You must first enable DHCP before performing other DHCP-related configurations. This configuration is necessary for both DHCP servers and DHCP relay agents.

Examples

# Enable DHCP.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp enable

1.1.2 dhcp select global

Syntax

VLAN interface view:

dhcp select global

undo dhcp select

System view:

dhcp select global { interface interface-type interface-number [ to interface-type interface-number ] | all }

undo dhcp select { interface interface-type interface-number [ to interface-type interface-number ] | all }

View

System view, VLAN interface view

Parameters

interface interface-type interface-number [ to interface-type interface-number ]: Specifies the interface(s) to operate in global address pool mode. The interface-type and interface-number arguments are the type and number of an interface. The to keyword separates the start and the end of an interface range.

all: Specifies all ports to operate in global address pool mode.

Description

Use the dhcp select global command to configure the specified interface(s) or all interfaces to operate in global DHCP address pool mode. Upon receiving a DHCP packet from a DHCP client through an interface operating in global DHCP address pool mode, the DHCP server chooses an IP address from a global DHCP address pool of the local DHCP server and assigns the address to the DHCP client.

Use the undo dhcp select command to restore the default DHCP packet processing mode.

By default, an interface operates in local DHCP server global address pool mode.

Examples

# Configure all interfaces to operate in global DHCP address pool mode, so that when a DHCP packet is received from a DHCP client through any interface, the DHCP server assigns an IP address in local global DHCP address pools to the DHCP client.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp select global all

1.1.3 dhcp select interface

Syntax

VLAN interface view:

dhcp select interface

undo dhcp select

System view:

dhcp select interface { interface interface-type interface-number [ to interface-type interface-number ] | all }

undo dhcp select { interface interface-type interface-number [ to interface-type interface-number ] | all }

View

System view, VLAN interface view

Parameters

interface interface-type interface-number [ to interface-type interface-number ]: Specifies the interface(s) to operate in interface address pool mode.

all: Specifies all interfaces to operate in interface address pool mode.

Description

Use the dhcp select interface command to configure the specified interface(s) to operate in DHCP interface address pool mode. Upon receiving a DHCP packet from a DHCP client through an interface operating in interface address pool mode, the DHCP server chooses an IP address from the interface address pool of the local DHCP server and assigns the address to the DHCP client.

Use the undo dhcp select command to restore the default DHCP packet processing mode.

By default, an interface operates in local DHCP server global address pool mode.

Examples

# Configure all interfaces to operate in interface address pool mode, so that when a DHCP packet is received from a DHCP client through any interface, the DHCP server assigns an IP address in the local interface address pool to the DHCP client.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp select interface all

1.1.4 dhcp server detect

Syntax

dhcp server detect

undo dhcp server detect

View

System view

Parameters

None

Description

Use the dhcp server detect command to enable the unauthorized DHCP server detecting function.

Use the undo dhcp server detect command to disable the unauthorized DHCP server detecting function.

By default, the unauthorized DHCP server detecting function is disabled.

With the unauthorized DHCP server detecting function enabled, a DHCP server tracks the information (such as the IP addresses and interfaces) of DHCP servers to enable the administrator to detect unauthorized DHCP servers in time and take proper measures.

Examples

# Enable the unauthorized DHCP server detecting function.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp server detect

1.1.5 dhcp server dns-list

Syntax

VLAN interface view:

dhcp server dns-list ip-address&<1-8>

undo dhcp server dns-list { ip-address | all }

System view:

dhcp server dns-list ip-address&<1-8> { interface interface-type interface-number [ to interface-type interface-number ] | all }

undo dhcp server dns-list { ip-address | all } { interface interface-type interface-number [ to interface-type interface-number ] | all }

View

System view, VLAN interface view

Parameters

ip-address&<1-8>: IP address of a DNS server. &<1-8> means you can provide up to eight DNS server IP addresses. When inputting more than one DNS server IP address, separate two neighboring IP addresses with a space.

interface interface-type interface-number [ to interface-type interface-number ]: Specifies the interface(s), through which you can specify the corresponding interface address pools.

all: (In comparison with the ip-address argument) Specifies all DNS server IP addresses.

all: (In comparison with the interface keyword) Specifies all interface address pools.

Description

Use the dhcp server dns-list command to configure DNS server IP address(es) for the DHCP address pool(s) of specified interface(s).

Use the undo dhcp server dns-list command to remove the DNS server IP address(es) configured for the DHCP address pool(s) of the specified interface(s).

By default, no DNS server IP address is configured for a DHCP interface address pool.

If you execute the dhcp server dns-list command repeatedly, the new configuration overwrites the previous one.

Related commands: dns-list.

Examples

# Configure the DNS server IP address 1.1.1.254 for the DHCP address pool of the VLAN-interface 1.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] interface Vlan-interface 1

[H3C-Vlan-interface1] dhcp server dns-list 1.1.1.254

1.1.6 dhcp server domain-name

Syntax

VLAN interface view:

dhcp server domain-name domain-name

undo dhcp server domain-name

System view:

dhcp server domain-name domain-name { interface interface-type interface-number [ to interface-type interface-number ] | all }

undo dhcp server domain-name { interface interface-type interface-number [ to interface-type interface-number ] | all }

View

System view, VLAN interface view

Parameters

domain-name: Domain name of the DHCP clients whose IP addresses are from the specified interface address pool(s). This argument is a string of 3 to 50 characters.

interface interface-type interface-number [ to interface-type interface-number ]: Specifies the interface(s), through which you can specify the corresponding interface address pool(s).

all: Specifies all interface address pools.

Description

Use the dhcp server domain-name command to configure a domain name for the DHCP clients whose IP addresses are from the specified interface address pool(s).

Use the undo dhcp server domain-name command to remove the configured domain name.

By default, no domain name is configured for the DHCP clients.

Related commands: domain-name.

Examples

# Set aabbcc.com as the domain name of the DHCP client whose IP address is obtained from the DHCP address pool of the current VLAN-interface 1.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] interface Vlan-interface 1

[H3C-Vlan-interface1] dhcp server domain-name aabbcc.com

1.1.7 dhcp server expired

Syntax

VLAN interface view:

dhcp server expired { day day [ hour hour [ minute minute ] ] | unlimited }

undo dhcp server expired

System view:

dhcp server expired { day day [ hour hour [ minute minute ] ] | unlimited } { interface interface-type interface-number [ to interface-type interface-number ] | all }

undo dhcp server expired { interface interface-type interface-number [ to interface-type interface-number ] | all }

View

System view, VLAN interface view

Parameters

day day: Specifies the number of days. The day argument ranges from 0 to 365.

hour hour: Specifies the number of hours. The hour argument ranges from 0 to 23.

minute minute: Specifies the number of minutes. The minute argument ranges from 0 to 59.

unlimited: Specifies that the lease time is unlimited. (But actually, the system limits the maximum lease time to about 25 years.)

interface interface-type interface-number [ to interface-type interface-number ]: Specifies the interface(s), through which you can specify the corresponding interface address pool(s).

all: Specifies all interface address pools.

Description

Use the dhcp server expired command to configure the lease time of the IP addresses in the specified interface address pool(s).

Use the undo dhcp server expired command to restore the default lease time.

The default lease time is one day.

Related commands: expired.

Examples

# Set the lease time of the IP addresses in all interface address pools to be 1 day, 2 hours and 3 minutes.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp server expired day 1 hour 2 minute 3 all

1.1.8 dhcp server forbidden-ip

Syntax

dhcp server forbidden-ip low-ip-address [ high-ip-address ]

undo dhcp server forbidden-ip low-ip-address [ high-ip-address ]

View

System view

Parameters

low-ip-address: IP address that is not available for being assigned to DHCP clients automatically (An IP address of this kind is known as a forbidden IP address). This argument also marks the lower end of the range of the forbidden IP addresses.

high-ip-address: IP address that is not available for being assigned to DHCP clients. This argument also marks the higher end of the range of the forbidden IP addresses. Note that this argument cannot be less than the low-ip-address argument. If you do not provide this argument, only the IP address specified by the low-ip-address argument is forbidden.

Description

Use the dhcp server forbidden-ip command to forbid the specified IP addresses in a DHCP address pool to be automatically assigned.

Use the undo dhcp server forbidden-ip command to cancel this configuration.

By default, all IP addresses in an address pool are allowed to be automatically assigned.

Note that the specified address range cannot contain statically-bound addresses when you use the undo dhcp server forbidden-ip command.

Related commands: dhcp server ip-pool, network, static-bind ip-address, dhcp server static-bind.

Examples

# Forbid the IP addresses in the range 10.110.1.1 to 10.110.1.63 to be automatically assigned.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp server forbidden-ip 10.110.1.1 10.110.1.63

1.1.9 dhcp server ip-pool

Syntax

dhcp server ip-pool pool-name

undo dhcp server ip-pool pool-name

View

System view

Parameters

pool-name: Name of a DHCP address pool, which uniquely identifies the address pool. This argument is a string of 1 to 35 characters.

Description

Use the dhcp server ip-pool command to create a global DHCP address pool and enter DHCP address pool view. If the address pool identified by the pool-name argument already exists, this command leads you to DHCP address pool view.

Use the undo dhcp server ip-pool command to remove a specified DHCP address pool.

By default, no global DHCP address pool is created.

Related commands: dhcp enable.

Examples

# Create DHCP address pool 0.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp server ip-pool 0

[H3C-dhcp-pool-0]

1.1.10 dhcp server nbns-list

Syntax

VLAN interface view:

dhcp server nbns-list ip-address&<1-8>

undo dhcp server nbns-list { ip-address | all }

System view:

dhcp server nbns-list ip-address&<1-8> { interface interface-type interface-number [ to interface-type interface-number ] | all }

undo dhcp server nbns-list { ip-address | all } { interface interface-type interface-number [ to interface-type interface-number ] | all }

View

System view, VLAN interface view

Parameters

ip-address&<1-8>: IP address of a WINS server. &<1-8> means you can provide up to eight WINS server IP addresses. When inputting more than one WINS server IP address, separate two neighboring IP addresses with a space.

interface interface-type interface-number [ to interface-type interface-number ]: Specifies the interface(s), through which you can specify the corresponding interface address pool(s).

all: (In comparison with the ip-address argument) Specifies all WINS server IP addresses.

all: (In comparison with the interface keyword) Specifies all interface address pools.

Description

Use the dhcp server nbns-list command to configure WINS server IP address(es) for the specified DHCP interface address pool(s).

Use the undo dhcp server nbns-list command to remove the WINS server IP address(es) configured for the specified DHCP interface address pool(s).

By default, no WINS server IP address is configured for a DHCP interface address pool.

If you execute the dhcp server nbns-list command repeatedly, the new configuration overwrites the previous one.

Related commands: nbns-list, dhcp server netbios-type.

Examples

# Configure the WINS server IP address 10.12.1.99 for all the DHCP interface address pools.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp server nbns-list 10.12.1.99 all

1.1.11 dhcp server netbios-type

Syntax

VLAN interface view:

dhcp server netbios-type { b-node | h-node | m-node | p-node }

undo dhcp server netbios-type

System view:

dhcp server netbios-type { b-node | h-node | m-node | p-node } { interface interface-type interface-number [ to interface-type interface-number ] | all }

undo dhcp server netbios-type { interface interface-type interface-number [ to interface-type interface-number ] | all }

View

System view, VLAN interface view

Parameters

b-node: Specifies the broadcast type. Nodes of this type acquire host name-to-IP address mapping by broadcasting.

p-node: Specifies the peer-to-peer type. Nodes of this type acquire host name-to-IP address mapping by communicating with the WINS server.

m-node: Specifies the m-typed mixed type. Nodes of this type are p-nodes with some broadcasting features. (The character m here stands for mixed.)

h-node: Specifies the hybrid type. Nodes of this type are b-nodes with peer-to-peer communicating features.

interface interface-type interface-number [ to interface-type interface-number ]: Specifies the interface(s), through which you can specify the corresponding interface address pools.

all: Specifies all interface address pools.

Description

Use the dhcp server netbios-type command to configure the NetBIOS node type of the DHCP clients whose IP addresses are from the specified interface address pool(s).

Use the undo dhcp server netbios-type command to restore the default NetBIOS node type.

By default, no NetBIOS node type is specified and the default NetBIOS node type is h-node.

Related commands: netbios-type, dhcp server nbns-list.

Examples

# Specify p-node as the NetBIOS node type of the DHCP clients whose IP addresses are from the DHCP address pool of VLAN-interface 1.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] interface vlan-interface 1

[H3C-Vlan-interface1] dhcp server netbios-type p-node

1.1.12 dhcp server option

Syntax

VLAN interface view:

dhcp server option code { ascii ascii-string | hex hex-string&<1-10> | ip-address ip-address&<1-8> }

undo dhcp server option code

System view:

dhcp server option code { ascii ascii-string | hex hex-string&<1-10> | ip-address ip-address&<1-8> } { interface interface-type interface-number [ to interface-type interface-number ] | all }

undo dhcp server option code { interface interface-type interface-number [ to interface-type interface-number ] | all }

View

System view, VLAN interface view

Parameters

code: Customized option number, ranging from 2 to 254. Note that this argument cannot be 3, 6, 15, 44, 46, 50 through 55, 57 through 59.

ascii ascii-string: Specifies a string that is of 1 to 63 characters. Note that each character of the string must be an ASCII character.

hex hex-string&<1-10>: Specifies strings, a hexadecimal number of 1 to 8 digits. &<1-10> means you can provide up to 10 such strings. When inputting more than one string, separate two neighboring strings with a space.

ip-address ip-address&<1-8>: Specifies IP addresses. &<1-8> means you can provide up to eight IP addresses. When inputting more than one IP address, separate two neighboring IP addresses with a space.

interface interface-type interface-number [ to interface-type interface-number ]: Specifies the interface(s), through which you can specify the corresponding interface address pools.

all: Specifies all interface address pools.

Description

Use the dhcp server option command to customize DHCP options for the specified DHCP interface address pool(s).

Use the undo dhcp server option command to remove the customized DHCP options.

If you execute the dhcp server option command repeatedly, the new configuration overwrites the previous one.

Related commands: option.

Examples

# Configure option 100 to be 0x11 and 0x22 for all DHCP interface address pools.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp server option 100 hex 11 22 all

1.1.13 dhcp server ping

Syntax

dhcp server ping { packets number | timeout milliseconds }

undo dhcp server ping { packets | timeout }

View

System view

Parameters

packets number: Specifies the number of the packets to be sent in a ping test. The number argument ranges from 0 to 10 and defaults to 2. Value 0 means no packet will be sent.

timeout milliseconds: Specifies the timeout time (in milliseconds) of each packet. The milliseconds argument ranges from 0 to 10,000 and defaults to 500.

Description

Use the dhcp server ping command to set the maximum number of the ICMP packets a DHCP server sends in a ping test and the maximum response timeout time of each ICMP packet.

Use the undo dhcp server ping command to restore the default settings.

Examples

# Set the maximum number of the packets the DHCP server sends in a ping test to 10, and the timeout time of each packet to 300 milliseconds.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp server ping packets 10

[H3C] dhcp server ping timeout 300

1.1.14 dhcp server static-bind

Syntax

dhcp server static-bind ip-address ip-address mac-address mac-address

undo dhcp server static-bind { ip-address ip-address | mac-address mac-address }

View

VLAN interface view

Parameters

ip-address: IP address to be statically bound. Note that the specified IP address must belong to the same network segment as that of the VLAN interface.

mac-address: MAC address to which the IP address is statically bound.

Description

Use the dhcp server static-bind command to statically bind an IP address of the current address pool to a MAC address.

Use the undo dhcp server static-bind command to cancel an IP-MAC address binding.

By default, no IP address in an address pool is statically bound.

It should be noted that:

l An IP address can be statically bound to only one MAC address. A MAC address can be bound with only one IP address statically.

l The IP address to be statically bound cannot be an interface IP address of the device; otherwise the static binding does not take effect. The device of the bound MAC address can also obtain another IP address.

Examples

# Statically bind the IP address 10.1.1.1 to the MAC address 0000-e03f-0305. (Assume that the interface address pool of VLAN-interface 1 already exists and the IP address belongs to the address pool.)

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] interface vlan-interface 1

[H3C-Vlan-interface1] dhcp server static-bind ip-address 10.1.1.1 mac-address 0000-e03f-0305

1.1.15 display dhcp server conflict

Syntax

display dhcp server conflict { all | ip ip-address }

View

Any view

Parameters

all: Specifies all IP addresses.

ip-address: Specifies an IP address.

Description

Use the display dhcp server conflict command to display the statistics of IP address conflicts on the DHCP server.

Related commands: reset dhcp server conflict.

Examples

# Display the statistics of IP address conflicts.

<H3C> display dhcp server conflict all

Address Discover Time

10.110.1.2 Jan 11 2003 11:57:07 PM

Table 1-1 Description on the fields of the display dhcp server conflict command

Field	Description
Address	Conflicting IP address
Discover Time	Time when the conflict is detected

1.1.16 display dhcp server expired

Syntax

display dhcp server expired { ip ip-address | pool [ pool-name ] | interface [ interface-type interface-number ] | all }

View

Any view

Parameters

ip ip-address: Specifies an IP address.

pool [ pool-name ]: Specifies a global address pool. The pool-name argument, a string of 1 to 35 characters, is the name of an address pool. If you do not provide this argument, this command applies to all global address pools.

interface [ interface-type interface-number ]: Specifies a VLAN interface. If you do not specify a VLAN interface, this command applies to all VLAN interfaces.

all: Specifies all DHCP address pools.

Description

Use the display dhcp server expired command to display the lease expiration information about an IP address, or the lease expiration information about all IP addresses in one or all DHCP address pools. When all the IP addresses in an address pool are assigned, the DHCP server assigns the IP addresses that are expired to DHCP clients.

Examples

# Display the lease expiration information about the IP addresses in all DHCP address pools.

<H3C> display dhcp server expired all

Global pool:

IP address Hardware address Lease expiration Type

Interface pool:

IP address Hardware address Lease expiration Type

--- total 0 entry ---

Table 1-2 Description on the fields of the display dhcp server expired command

Field	Description
Global pool	The information about the expired IP addresses of global address pools
Interface pool	The information about the expired IP addresses of interface address pools
IP address	Bound IP addresses
Hardware address	MAC addresses to which IP addresses are bound
Lease expiration	The time when a lease time expires
Type	Address binding type

1.1.17 display dhcp server free-ip

Syntax

display dhcp server free-ip

View

Any view

Parameters

None

Description

Use the display dhcp server free-ip command to display the free (that is, unassigned) IP addresses.

Examples

# Display the free IP addresses.

<H3C> display dhcp server free-ip

IP Range from 1.0.0.0 to 2.2.2.1

IP Range from 2.2.2.3 to 2.255.255.255

IP Range from 4.0.0.0 to 4.255.255.255

IP Range from 5.5.5.0 to 5.5.5.0

IP Range from 5.5.5.2 to 5.5.5.255

1.1.18 display dhcp server ip-in-use

Syntax

display dhcp server ip-in-use { ip ip-address | pool [ pool-name ] | interface [ interface-type interface-number ] | all }

View

Any view

Parameters

ip ip-address: Specifies an IP address.

interface [ interface-type interface-number ]: Specifies a VLAN interface. If you do not specify a VLAN interface, this command applies to all VLAN interfaces.

all: Specifies all address pools.

Description

Use the display dhcp server ip-in-use command to display the address binding information of an IP address, the specified DHCP address pool(s) or all DHCP address pools.

Related commands: reset dhcp server ip-in-use.

Examples

# Display the address binding information of all DHCP address pools.

<H3C> display dhcp server ip-in-use all

Global pool:

IP address Hardware address Lease expiration Type

2.2.2.2 4444-4444-4444 NOT Used Manual

Interface pool:

IP address Hardware address Lease expiration Type

5.5.5.1 0050-ba28-930a NOT Used Manual

--- total 2 entry ---

Table 1-3 Description on the fields of the display dhcp server ip-in-use command

Field	Description
Global pool	Address binding information of global DHCP address pools
Interface pool	Address binding information of interface DHCP address pools
IP address	Bound IP address
Hardware address	MAC address to which the IP address is bound
Lease expiration	Time when the lease expires
Type	Address binding type

1.1.19 display dhcp server statistics

Syntax

display dhcp server statistics

View

Any view

Parameters

None

Description

Use the display dhcp server statistics command to display the statistics on a DHCP server.

Related commands: reset dhcp server statistics.

Examples

# Display the statistics on a DHCP server.

<H3C> display dhcp server statistics

Global Pool:

Pool Number: 5

Binding

Auto: 0

Manual: 1

Expire: 0

Interface Pool:

Pool Number: 1

Binding

Auto: 1

Manual: 0

Expire: 0

Boot Request: 6

Dhcp Discover: 1

Dhcp Request: 4

Dhcp Decline: 0

Dhcp Release: 1

Dhcp Inform: 0

Boot Reply: 4

Dhcp Offer: 1

Dhcp Ack: 3

Dhcp Nak: 0

Bad Messages: 0

Table 1-4 Description on the fields of the display dhcp server statistics command

Field	Description
Global Pool	Statistics about global address pools
Interface Pool	Statistics about interface address pools
Pool Number	Number of address pools
Auto	Number of the automatically bound IP addresses
Manual	Number of the manually bound IP addresses
Expire	Number of the expired IP addresses
Boot Request: 6 Dhcp Discover: 1 Dhcp Request: 4 Dhcp Decline: 0 Dhcp Release: 1 Dhcp Inform: 0	Statistics about the DHCP packets received from DHCP clients
Boot Reply: 4 Dhcp Offer: 1 Dhcp Ack: 3 Dhcp Nak: 0	Statistics about the DHCP packets sent to DHCP clients
Bad Messages	Number of the error DHCP packets

1.1.20 display dhcp server tree

Syntax

display dhcp server tree { pool [ pool-name ] | interface [ interface-type interface-number ] | all }

View

Any view

Parameters

interface [ interface-type interface-number ]: Specifies a VLAN interface. If you do not specify a VLAN interface, this command applies to all VLAN interfaces.

all: Specifies all address pools.

Description

Use the display dhcp server tree command to display information about address pool tree.

Examples

# Display the information about address pool tree.

<H3C> display dhcp server tree all

Global pool:

Pool name: 5

network 10.10.1.0 mask 255.255.255.0

Child node:6

Sibling node:7

option 10 ip-address 255.0.0.0

expired 1 0 0

Pool name: 6

static-bind ip-address 10.10.1.2 mask 255.0.0.0

static-bind mac-address 000f-e2fc-0001

Parent node:5

option 10 ip-address 255.255.0.0

expired 1 0 0

Pool name: 7

network 10.10.1.64 mask 255.255.255.192

PrevSibling node:5

option 10 ip-address 255.0.0.0

gateway-list 2.2.2.2

dns-list 1.1.1.1

domain-name 444444

nbns-list 3.3.3.3

expired 1 0 0

Table 1-5 Description on the fields of the display dhcp server tree command

Field	Description
Global pool	Information about global address pools
Interface pool	Information about interface address pools
Pool name	Address pool name
network	Assignable IP address range
static-bind ip-address 10.10.1.2 mask 255.0.0.0 static-bind mac-address 000f-e2fc-0001	Statically bound IP and MAC addresses
Child node:6	The address pool 6 is the child node of this node. This field can display the information about the following types of node: Child node: Displays the information about an address pool that is a child of the current address pool. Parent node: Displays the information about the address pool that is the parent of the current address pool. Sibling node: Displays the information about the next sibling address pool of the current address pool. (The order of sibling address pools are determined by the time when they are configured.) PrevSibling node: Displays the information about the previous sibling address pool of the current address pool.
option	Customized DHCP options
expired	The address lease time (in terms of number of days, hours, and minutes)
gateway-list	List of the gateways configured for the DHCP clients
dns-list	List of the DNS servers configured for the DHCP clients
domain-name	The domain name configured for the DHCP clients
nbns-list	List of the WINS servers configured for the DHCP clients

1.1.21 dns-list

Syntax

dns-list ip-address&<1-8>

undo dns-list { ip-address | all }

View

DHCP address pool view

Parameters

ip-address&<1-8>: IP address of a DNS server. &<1-8> string means you can provide up to eight DNS server IP addresses. When inputting more than one IP address, separate two neighboring IP addresses with a space.

all: Specifies all configured DNS server IP addresses.

Description

Use the dns-list command to configure one or multiple DNS server IP addresses for a global DHCP address pool.

Use the undo dns-list command to remove one or all DNS server IP addresses configured for the DHCP address pool.

By default, no DNS server IP address is configured.

If you execute the dns-list command repeatedly, the new configuration overwrites the previous one.

Related commands: dhcp server dns-list, dhcp server ip-pool.

Examples

# Configure the DNS server IP address 1.1.1.254 for global DHCP address pool 0.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp server ip-pool 0

[H3C-dhcp-pool-0] dns-list 1.1.1.254

1.1.22 domain-name

Syntax

domain-name domain-name

undo domain-name

View

DHCP address pool view

Parameters

domain-name: Domain name for the DHCP clients of a global DHCP address pool, a string of 3 to 50 characters.

Description

Use the domain-name command to configure a domain name for the DHCP clients of a global DHCP address pool.

Use the undo domain-name command to remove the domain name.

By default, no domain name is configured for the DHCP clients of a global DHCP address pool.

Related commands: dhcp server ip-pool, dhcp server domain-name.

Examples

# Configure the domain name “mydomain.com” for the DHCP clients of the global DHCP address pool 0.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp server ip-pool 0

[H3C-dhcp-pool-0] domain-name mydomain.com

1.1.23 expired

Syntax

expired { day day [ hour hour [ minute minute ] ] | unlimited }

undo expired

View

DHCP address pool view

Parameters

day day: Specifies the number of days. The day argument ranges from 0 to 365.

hour hour: Specifies the number of hours. The hour argument ranges from 0 to 23.

minute minute: Specifies the number of minutes. The minute argument ranges from 0 to 59.

unlimited: Specifies that the lease time is unlimited. (But actually, the system limits the maximum lease time to about 25 years.)

Description

Use the expired command to configure the lease time of the IP addresses in a global DHCP address pool.

Use the undo expired command to restore the default lease time.

The default lease time is one day.

Related commands: dhcp server ip-pool, dhcp server expired.

Examples

# Set the lease time of the IP addresses in the global DHCP address pool 0 to 1 day, 2 hours and 3 minutes.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp server ip-pool 0

[H3C-dhcp-pool-0] expired day 1 hour 2 minute 3

1.1.24 gateway-list

Syntax

gateway-list ip-address&<1-8>

undo gateway-list { ip-address | all }

View

DHCP address pool view

Parameters

ip-address&<1-8>: IP address of a gateway. &<1-8> means you can provide up to eight gateway IP addresses. When inputting more than one IP address, separate two neighboring IP addresses with a space.

all: Specifies all configured gateway IP addresses.

Description

Use the gateway-list command to configure one or multiple gateway IP addresses for the DHCP clients of a DHCP address pool.

Use the undo gateway-list command to remove one or all the configured gateway IP addresses configured for the DHCP address pool.

By default, no gateway IP address is configured.

If you execute the gateway-list command repeatedly, the new configuration overwrites the previous one.

Examples

# Configure the gateway IP address 10.110.1.99 for the global DHCP address pool 0.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp server ip-pool 0

[H3C-dhcp-pool-0] gateway-list 10.110.1.99

1.1.25 nbns-list

Syntax

nbns-list ip-address&<1-8>

undo nbns-list { ip-address | all }

View

DHCP address pool view

Parameters

ip-address&<1-8>: IP address of a WINS server. &<1-8> means you can provide up to eight WINS server IP addresses. When inputting more than one IP address, separate two neighboring IP addresses with a space.

all: Specifies all configured WINS server IP addresses.

Description

Use the nbns-list command to configure one or multiple WINS server IP addresses for the DHCP clients of a global DHCP address pool.

Use the undo nbns-list command to remove one or all WINS server IP addresses configured for the DHCP clients.

By default, no WINS server IP address is configured.

If you execute the nbns-list command repeatedly, the new configuration overwrites the previous one.

Related commands: dhcp server ip-pool, dhcp server nbns-list, netbios-type.

Examples

# Configure the WINS server IP address 10.12.1.99 for the global DHCP address pool 0.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp server ip-pool 0

[H3C-dhcp-pool-0] nbns-list 10.12.1.99

1.1.26 netbios-type

Syntax

netbios-type { b-node | h-node | m-node | p-node }

undo netbios-type

View

DHCP address pool view

Parameters

b-node: Specifies the broadcast type. Nodes of this type acquire host name-to-IP address mapping by broadcasting.

p-node: Specifies the peer-to-peer type. Nodes of this type acquire host name-to-IP address mapping by communicating with the WINS server.

m-node: Specifies the mixed type. Nodes of this type are p-nodes with some broadcasting features.

h-node: Specifies the hybrid type. Nodes of this type are b-nodes with peer-to-peer communicating features.

Description

Use the netbios-type command to configure the DHCP clients of a global address pool to be of specified NetBIOS node type.

Use the undo netbios-type command to restore the default NetBIOS node type.

By default, no NetBIOS node type is specified. In this case, the client uses h-node.

Related commands: dhcp server ip-pool, dhcp server netbios-type, nbns-list.

Examples

# Configure the DHCP clients of the global DHCP address pool 0 to be of b-node type.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp server ip-pool 0

[H3C-dhcp-pool-0] netbios-type b-node

1.1.27 network

Syntax

network ip-address [ mask mask ]

undo network

View

DHCP address pool view

Parameters

ip-address: IP address of a network segment, used to specify an IP address range.

mask mask: Specifies a subnet mask in dotted decimal notation. If you do not specify the mask argument, the default subnet mask is used.

Description

Use the network command to configure a dynamically assigned IP address range (where IP addresses will be dynamically assigned to DHCP clients).

Use the undo network command to remove a dynamically assigned IP address range.

By default, no such IP address range is configured for a DHCP address pool.

Note that you can configure only one such IP address range for a DHCP address pool. If you execute the network command repeatedly, the new configuration overwrites the previous one.

Related commands: dhcp server ip-pool, dhcp server forbidden-ip.

Examples

# Configure the dynamically assigned IP address range 192.168.8.0/24 for the global DHCP address pool 0.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp server ip-pool 0

[H3C-dhcp-pool-0] network 192.168.8.0 mask 255.255.255.0

1.1.28 option

Syntax

option code { ascii ascii-string | hex hex-string&<1-10> | ip-address ip-address&<1-8> }

undo option code

View

DHCP address pool view

Parameters

code: Customized option number ranging from 2 to 254. Note that this argument cannot be 3, 6, 15, 44, 46, 50 through 55, 57 through 59.

ascii ascii-string: Specifies a string that is of 1 to 63 ASCII characters.

hex hex-string&<1-10>: Specifies strings, a hexadecimal number of 1 to 8 digits. &<1-10> means that you can provide up to 10 such strings. When entering more than one strings, separate two neighboring strings with a space.

ip-address ip-address&<1-8>: Specifies IP addresses. &<1-8> means that you can provide up to eight IP addresses. When entering more than one IP address, separate two neighboring IP addresses with a space.

Description

Use the option command to customize DHCP options for a global DHCP address pool.

Use the undo option command to remove the customized DHCP options.

If you execute the option command repeatedly, the new configuration overwrites the previous one.

Related commands: dhcp server ip-pool, dhcp server option.

Examples

# Configure option 100 to be 0x11 and 0x22 for the global DHCP address pools.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp server ip-pool 0

[H3C-dhcp-pool-0] option 100 hex 11 22

1.1.29 reset dhcp server conflict

Syntax

reset dhcp server conflict { all | ip ip-address }

View

User view

Parameters

ip ip-address: Specifies an IP address, whose conflict statistics will be cleared.

all: Clears all address conflict statistics.

Description

Use the reset dhcp server conflict command to clear address conflict statistics.

Related commands: display dhcp server conflict.

Examples

# Clear all address conflict statistics.

<H3C> reset dhcp server conflict all

1.1.30 reset dhcp server ip-in-use

Syntax

reset dhcp server ip-in-use { all | interface [ interface-type interface-number ] | ip ip-address | pool [ pool-name ] }

View

User view

Parameters

all: Clears the dynamic address binding information about all IP addresses.

interface [ interface-type interface-number ]: Clears the dynamic address binding information about a specified interface address pool. If you do not specify the interface-number argument, this command clears the dynamic address binding information about all interface address pools.

ip ip-address: Clears the dynamic address binding information about a specified IP address.

pool [ pool-name ]: Clears the dynamic address binding information about a specified address pool. The pool-name argument, a string of 1 to 35 characters, is the name of an address pool. If you do not provide this argument, this command clears the dynamic address binding information about all global address pools.

Description

Use the reset dhcp server ip-in-use command to clear the specified or all dynamic address binding information.

Related commands: display dhcp server ip-in-use.

Examples

# Clear the dynamic address binding information about the IP address 10.110.1.1.

<H3C> reset dhcp server ip-in-use ip 10.110.1.1

1.1.31 reset dhcp server statistics

Syntax

reset dhcp server statistics

View

User view

Parameters

None

Description

Use the reset dhcp server statistics command to clear the statistics on a DHCP server, such as the number of DHCP unrecognized packets/request packets/response packets.

Related commands: display dhcp server statistics.

Examples

# Clear the statistics on a DHCP server.

<H3C> reset dhcp server statistics

1.1.32 static-bind ip-address

Syntax

static-bind ip-address ip-address [ mask mask ]

undo static-bind ip-address

View

DHCP address pool view

Parameters

ip-address: IP address to be bound.

mask mask: Subnet mask of the specified IP address. If you do not specify the mask argument, the default subnet mask is used.

Description

Use the static-bind ip-address command to specify an IP address to be statically bound to a MAC address.

Use the undo static-bind ip-address command to remove a statically bound IP address.

By default, no IP address is statically bound.

Note that:

l The static-bind ip-address command must be used together with the static-bind mac-address command, to specify a statically bound IP address or MAC address.

l If you execute the static-bind ip-address command repeatedly, the new configuration overwrites the previous one.

Related commands: dhcp server ip-pool, static-bind mac-address.

Examples

# Bind the IP address 10.1.1.1 (with the subnet mask 255.255.255.0) to the MAC address 0000-e03f-0305.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp server ip-pool 0

[H3C-dhcp-pool-0] static-bind ip-address 10.1.1.1 mask 255.255.255.0

[H3C-dhcp-pool-0] static-bind mac-address 0000-e03f-0305

1.1.33 static-bind mac-address

Syntax

static-bind mac-address mac-address

undo static-bind mac-address

View

DHCP address pool view

Parameters

mac-address: MAC address of the host to which the IP address is to be bound. You need to provide this argument in the form of H-H-H.

Description

Use the static-bind mac-address command to specify a MAC address to which an IP address will be bound statically.

Use the undo static-bind mac-address command to remove such a MAC address.

By default, no such MAC address is specified.

Note that:

l The static-bind ip-address command must be used together with the static-bind mac-address command, to respectively specify a statically bound IP address and MAC address.

l If you execute the static-bind mac-address command repeatedly, the new configuration overwrites the previous one.

Related commands: dhcp server ip-pool, static-bind ip-address.

Examples

# Bind the IP address 10.1.1.1 (with the subnet mask 255.255.255.0) to the MAC address 0000-e03f-0305.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp server ip-pool 0

[H3C-dhcp-pool-0] static-bind ip-address 10.1.1.1 mask 255.255.255.0

[H3C-dhcp-pool-0] static-bind mac-address 0000-e03f-0305

Chapter 2 DHCP Relay Agent Configuration Commands

2.1 DHCP Relay Agent Configuration Commands

2.1.1 address-check

Syntax

address-check enable

address-check disable

View

VLAN interface view

Parameters

None

Description

Use the address-check enable command to enable the address checking function of the DHCP relay agent.

Use the address-check disable command to disable the address checking function of the DHCP relay agent.

By default, the address checking function of the DHCP relay agent is disabled on a VLAN interface.

Examples

# Enable the address checking function of the DHCP relay agent on VLAN-interface 1.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] interface vlan-interface 1

[H3C-Vlan-interface1] address-check enable

2.1.2 address-check dhcp-relay

Syntax

address-check dhcp-relay enable

address-check dhcp-relay disable

View

VLAN interface view

Parameters

None

Description

Use the address-check dhcp-relay enable command to validate the dynamic entries generated by the DHCP relay agent.

Use the address-check dhcp-relay disable command to invalidate the dynamic entries generated by the DHCP relay agent.

By default, the dynamic entries generated by the DHCP relay agent are valid.

This configuration will take effect only after the address checking function of the DHCP relay agent on the VLAN interface is enabled.

Examples

# Invalidate the dynamic entries generated by the DHCP relay agent.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] interface Vlan-interface 1

[H3C-Vlan-interface1] address-check enable

[H3C-Vlan-interface1] address-check dhcp-relay disable

2.1.3 address-check no-matched

Syntax

address-check no-matched enable

address-check no-matched disable

View

VLAN interface view

Parameters

None

Description

Use the address-check no-matched enable command to forbid freely-connected clients to pass DHCP security check.

Use the address-check no-matched disable command to allow freely-connected clients to pass DHCP security check.

By default, freely-connected clients are not allowed to pass DHCP security check.

Freely-connected clients refer to the clients whose IP addresses and MAC addresses are not in the DHCP security table.

This configuration will take effect only after the address checking function of the DHCP relay agent on the VLAN interface is enabled.

Examples

# Configure to not allow freely-connected clients to pass DHCP security check on VLAN-interface 1.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] interface Vlan-interface 1

[H3C-Vlan-interface1] address-check enable

[H3C-Vlan-interface1] address-check no-matched enable

2.1.4 dhcp relay information enable

Syntax

dhcp relay information enable

undo dhcp relay information enable

View

System view

Parameters

None

Description

Use the dhcp relay information enable command to enable option 82 supporting on a DHCP relay agent, through which you can enable the DHCP relay agent to insert option 82 into DHCP request packets sent to a DHCP server.

Use the undo dhcp relay information enable command to disable option 82 supporting on a DHCP relay agent, through which you can disable the DHCP relay agent from inserting option 82 into DHCP request packets sent to a DHCP server.

By default, this function is disabled.

Related commands: dhcp relay information strategy.

Examples

# Enable option 82 supporting on a DHCP relay agent.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp relay information enable

2.1.5 dhcp relay information strategy

Syntax

dhcp relay information strategy { drop | keep | replace }

undo dhcp relay information strategy

View

System view

Parameters

drop: Specifies to discard the DHCP request packets that carry option 82.

keep: Specifies to remain the DHCP request packets that carry option 82 unchanged.

replace: Specifies to replace option 82 carried by a DHCP request packet with that of the DHCP relay agent.

Description

Use the dhcp relay information strategy command to instruct a DHCP relay agent to perform specified operations to DHCP request packets that carry option 82.

Use the undo dhcp relay information strategy command to instruct a DHCP relay agent to perform the default operations to DHCP request packets that carry option 82.

By default, the DHCP relay agent replaces the option 82 carried by a DHCP request packet with its own option 82.

Related commands: dhcp relay information enable

Examples

# Instruct the DHCP relay agent to drop the DHCP request packets that carry option 82.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp relay information strategy drop

2.1.6 dhcp-security static

Syntax

dhcp-security static ip-address mac-address

undo dhcp-security { ip-address | all | dynamic | static }

View

System view

Parameters

ip-address: User IP address.

mac-address: User MAC address.

all: Removes all user address entries.

dynamic: Removes dynamic user address entries.

static: Removes static user address entries.

Description

Use the dhcp-security static command to configure a static user address entry.

Use the undo dhcp-security command to remove one or all user address entries, or all user address entries of a specified type.

Related commands: display dhcp-security.

Examples

# Configure a user address entry for the DHCP server group, with the user IP address being 1.1.1.1 and the user MAC address being 0005-5D02-F2B3.

<H3C> system-view

System View: return to User View with Ctrl+Z

[H3C] dhcp-security static 1.1.1.1 0005-5D02-F2B3

2.1.7 dhcp-server

Syntax

dhcp-server groupNo

undo dhcp-server

View

VLAN interface view

Parameters

groupNo: DHCP server group number. This argument ranges from 0 to 19.

Description

Use the dhcp-server command to map the current VLAN interface to a DHCP server group.

Use the undo dhcp-server command to cancel the mapping.

Related commands: dhcp-server ip, display dhcp-server, display dhcp-server interface vlan-interface.

Examples

# Specify that VLAN-interface 1 corresponds to DHCP server group 1.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] interface vlan-interface 1

[H3C-Vlan-interface1] dhcp-server 1

2.1.8 dhcp-server ip

Syntax

dhcp-server groupNo ip ip-address&<1-8>

undo dhcp-server groupNo

View

System view

Parameters

groupNo: DHCP server group number, ranging from 0 to 19.

ip-address&<1-8>: IP address of the DNS server. &<1-8> indicates that up to eight IP addresses can be input, with any two IP addresses separated by a space.

Description

Use the dhcp-server ip command to configure the DHCP server IP address(es) in a specified DHCP server group.

Use the undo dhcp-server command to remove all DHCP server IP addresses in a DHCP server group.

Related commands: dhcp-server, display dhcp-server.

Examples

# Configure three DHCP server IP addresses 1.1.1.1, 2.2.2.2, and 3.3.3.3 for DHCP server group 1, so that this group contains three DHCP servers (server 1, server 2 and server 3).

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp-server 1 ip 1.1.1.1 2.2.2.2 3.3.3.3

2.1.9 display dhcp-security

Syntax

display dhcp-security [ ip-address | dynamic | static ]

View

Any view

Parameters

ip-address: IP address. This argument is used to display the user address entry with the specified IP address.

dynamic: Displays the dynamic user address entries.

static: Displays the static user address entries.

Description

Use the display dhcp-security command to display one or all user address entries, or a specified type of user address entries in the valid user address table of a DHCP server group.

Examples

# Display all user address entries contained in the valid user address table of the DHCP server group.

<H3C> display dhcp-security

IP Address MAC Address IP Address Type

2.2.2.3 0005-5d02-f2b2 Static

3.3.3.3 0005-5d02-f2b3 Dynamic

--- 2 dhcp-security item(s) found ---

Table 2-1 Description on the fields of the display dhcp-security command

Field	Description
IP Address	IP address of a user of the DHCP server group
MAC Address	MAC address of the user of the DHCP server group
IP Address Type	Type of the user address entry (static/dynamic)

2.1.10 display dhcp-server

Syntax

display dhcp-server groupNo

View

Any view

Parameters

groupNo: DHCP server group number, ranging from 0 to 19.

Description

Use the display dhcp-server command to display information about a specified DHCP server group.

Related commands: dhcp-server ip, dhcp-server, display dhcp-server interface vlan-interface.

Examples

# Display information about DHCP server group 0.

<H3C> display dhcp-server 0

IP address of DHCP server group 0: 1.1.1.1

IP address of DHCP server group 0: 2.2.2.2

IP address of DHCP server group 0: 3.3.3.3

IP address of DHCP server group 0: 4.4.4.4

IP address of DHCP server group 0: 5.5.5.5

IP address of DHCP server group 0: 6.6.6.6

IP address of DHCP server group 0: 7.7.7.7

IP address of DHCP server group 0: 8.8.8.8

Messages from this server group: 0

Messages to this server group: 0

Messages from clients to this server group: 0

Messages from this server group to clients: 0

DHCP_OFFER messages: 0

DHCP_ACK messages: 0

DHCP_NAK messages: 0

DHCP_DECLINE messages: 0

DHCP_DISCOVER messages: 0

DHCP_REQUEST messages: 0

DHCP_INFORM messages: 0

DHCP_RELEASE messages: 0

BOOTP_REQUEST messages: 0

BOOTP_REPLY messages: 0

Table 2-2 Description on the fields of the display dhcp-server command

Field	Description
IP address of DHCP server group 0:	DHCP server IP addresses of DHCP server group 0
Messages from this server group	Number of packets received from the DHCP server group
Messages to this server group	Number of packets sent to the DHCP server group
Messages from clients to this server group	Number of packets received from the DHCP clients
Messages from this server group to clients	Number of packets sent to the DHCP clients
DHCP_OFFER messages	Number of received DHCP-OFFER packets
DHCP_ACK messages	Number of received DHCP-ACK packets
DHCP_NAK messages	Number of received DHCP-NAK packets
DHCP_DECLINE messages	Number of received DHCP-DECLINE packets
DHCP_DISCOVER messages	Number of received DHCP-DISCOVER packets
DHCP_REQUEST messages	Number of received DHCP-REQUEST packets
DHCP_INFORM messages	Number of received DHCP-INFORM packets
DHCP_RELEASE messages	Number of received DHCP-RELEASE packets
BOOTP_REQUEST messages	Number of BOOTP request packets
BOOTP_REPLY messages	Number of BOOTP response packets

2.1.11 display dhcp-server interface

Syntax

display dhcp-server interface Vlan-interface vlan-id

View

Any view

Parameters

vlan-id: VLAN ID.

Description

Use the display dhcp-server interface command to display information about the DHCP server group to which a VLAN interface is mapped.

Related commands: dhcp-server, display dhcp-server.

Examples

# Display information about the DHCP server group to which VLAN 2 interface is mapped.

<H3C> display dhcp-server interface vlan-interface 2

The DHCP server group of this interface is 0

The above display information indicates the VLAN 2 interface is mapped to DHCP server group 0.

2.1.12 reset dhcp-server

Syntax

reset dhcp-server groupNo

View

User view

Parameters

groupNo: DHCP server group number, ranging from 0 to 19.

Description

Use the reset dhcp-server command to clear the statistics information of the specified DHCP server group.

Related commands: dhcp server, display dhcp-server.

Examples

# Clear the statistics information of DHCP server group 2.

<H3C> reset dhcp-server 2

Chapter 3 DHCP Snooping Configuration Commands

3.1 DHCP Snooping Configuration Commands

3.1.1 dhcp-snooping

Syntax

dhcp-snooping

undo dhcp-snooping

View

System view

Parameters

None

Description

Use the dhcp-snooping command to enable the DHCP snooping function, so as to allow the switch to listen to the DHCP broadcast packets.

Use the undo dhcp-snooping command to disable the DHCP snooping function.

By default, the DHCP snooping function is disabled.

Related commands: display dhcp-snooping.

Examples

# Enable the DHCP snooping function.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp-snooping

3.1.2 dhcp-snooping trust

Syntax

dhcp-snooping trust

undo dhcp-snooping trust

View

Ethernet port view

Parameters

None

Description

Use the dhcp-snooping trust command to specify an Ethernet port as a trusted port.

Use the undo dhcp-snooping trust command to restore an Ethernet port to an untrusted port.

DHCP snooping security allow you to specify a port as a trusted port or an untrusted port, so that DHCP clients can obtain IP addresses from valid DHCP servers.

l Trusted ports can be used to connect DHCP servers or ports of other switches. Untrusted ports can be used to connect DHCP clients or networks.

l Trusted ports forward any received DHCP packets to ensure that DHCP clients can obtain IP addresses from valid DHCP servers. Untrusted ports discard the DHCP-ACK and DHCP-OFFER responses received from DHCP servers.

By default, all the ports of a switch are untrusted ports.

Related commands: display dhcp-snooping trust.

Examples

# Specify the Ethernet 2/0/1 port as a trusted port.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] interface Ethernet2/0/1

[H3C-Ethernet2/0/1] dhcp-snooping trust

3.1.3 dhcp-snooping information enable

Syntax

dhcp-snooping information enable

undo dhcp-snooping information enable

View

System view

Parameters

None

Description

Use the dhcp-snooping information enable command to enable DHCP-Snooping option 82.

Use the undo dhcp-snooping information enable command to disable DHCP-Snooping option 82.

DHCP-Snooping option 82 is disabled by default.

Examples

# Enable DHCP-Snooping option 82.

<H3C> system-view

System View: return to User View with Ctrl+Z.

[H3C] dhcp-snooping information enable

DHCP snooping option 82 is enabled globally.

3.1.4 display dhcp-snooping

Syntax

display dhcp-snooping

View

Any view

Parameters

None

Description

Use the display dhcp-snooping command to display the IP-MAC mapping relations recorded by the DHCP snooping-enabled switch.

Related commands: dhcp-snooping.

Examples

# Display the IP-MAC mapping relations recorded by the DHCP snooping-enabled switch.

<H3C> display dhcp-snooping

DHCP snooping is enabled globally.

Type : D--Dynamic , S--Static

Type IP Address MAC Address Lease VLAN Interface

==== =============== =============== ========= ==== =================

--- 0 DHCP snooping item(s) found ---

3.1.5 display dhcp-snooping count

Syntax

display dhcp-snooping count

View

Any view

Parameters

None

Description

Use the display dhcp-snooping count command to display the total number of DHCP-Snooping entries.

Examples

# Display the total number of DHCP-Snooping entries.

<H3C> display dhcp-snooping count

1 dhcp-snooping item(s) found

3.1.6 display dhcp-snooping trust

Syntax

display dhcp-snooping trust

View

Any view

Parameters

None

Description

Use the display dhcp-snooping trust command to display the (enabled/disabled) state of the DHCP snooping function and the trusted ports.

Related commands: dhcp-snooping trust.

Examples

# Display the state of the DHCP snooping function and the trusted ports.

<H3C> display dhcp-snooping trust

Interface Trusted

=================================

Ethernet3/0/3 Trusted

The above information indicates that the Ethernet 3/0/3 port is a trusted port.

3.1.7 display dhcp-snooping vlan

Syntax

display dhcp-snooping vlan { vlan-list | all }

View

Any view

Parameters

vlan-list: Displays the VLAN lists in the specified VLAN range, in the format of vlan-list = { vlan-id [ to vlan-id ] }&<1-10>. where, vlan-id is in the range of 1 to 4094, and &<1-10> means that you can specify up to 10 VLANs or VLAN ranges for this argument.

all: Displays all the IP-MAC mapping relations recorded by the DHCP-Snooping-enabled switch.

Description

Use the display dhcp-snooping vlan command to display the IP-MAC mapping relations recorded by the DHCP-Snooping-enabled switch in the specified VLAN.

Examples

# Display the IP-MAC mapping relations recorded by the DHCP-Snooping-enabled switch in VLAN 2.

<H3C> display dhcp-snooping vlan 2

DHCP snooping is enabled globally.

The client binding table for untrusted ports on the VLANs assigned.

Type : D--Dynamic , S--Static

Type IP Address MAC Address Lease VLAN Interface

==== =============== =============== ========= ==== =================

D 3.3.3.2 0012-3f83-6eef 20 2 Ethernet3/0/1

--- 1 dhcp snooping item(s) found ---

3.1.8 reset dhcp-snooping

Syntax

reset dhcp-snooping [ ip-address ]

View

User view

Parameters

ip-address: Clears the IP-MAC mapping relations recorded by the DHCP-Snooping-enabled switch.

Description

Use the reset dhcp-snooping command to clear the specified IP-MAC mapping relation or all the IP-MAC mapping relations recorded by the DHCP-Snooping-enabled switch.

Related commands: dhcp server, display dhcp-server.

Examples

# Clear the 10.1.1.1-MAC mapping relation recorded by the DHCP-Snooping-enabled switch.

<H3C> reset dhcp-snooping 10.1.1.1

H3C S7500 Series Command Manual(Release 3100 Series)-(V1.04)

3.1.8 reset dhcp-snooping

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