Table of Contents

Chapter 1 DHCP Snooping Configuration Commands. 1-1

1.1 DHCP Snooping Configuration Commands. 1-1

1.1.1 dhcp-snooping. 1-1

1.1.2 dhcp-snooping trust 1-1

1.1.3 display dhcp-snooping. 1-2

1.1.4 display dhcp-snooping trust 1-3

Chapter 2 DHCP/BOOTP Client Configuration. 2-1

2.1 DHCP Client Configuration Commands. 2-1

2.1.1 debugging dhcp client 2-1

2.1.2 debugging dhcp irf xha. 2-1

2.1.3 display dhcp client 2-2

2.1.4 ip address dhcp-alloc. 2-3

2.2 BOOTP Client Configuration Commands. 2-4

2.2.1 display bootp client 2-4

2.2.2 ip address bootp-alloc. 2-5

 

Chapter 1  DHCP Snooping Configuration Commands

1.1  DHCP Snooping Configuration Commands

1.1.1  dhcp-snooping

Syntax

dhcp-snooping

undo dhcp-snooping

View

System view

Parameter

None

Description

Use the dhcp-snooping command to enable the DHCP snooping function.

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

By default, the DHCP snooping function is disabled.

Related command: display dhcp-snooping.

Example

# Enter system view.

<H3C> system-view

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

# Enable the DHCP snooping function.

[H3C] dhcp-snooping

1.1.2  dhcp-snooping trust

Syntax

dhcp-snooping trust

undo dhcp-snooping trust

View

Ethernet port view

Parameter

None

Description

Use the dhcp-snooping trust command to set an Ethernet port to 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 set a port to a trusted port or an untrusted port, so that DHCP clients can obtain IP addresses from only 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 command: display dhcp-snooping trust.

Example

# Enter system view.

<H3C> system-view

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

# Set the Ethernet1/0/1 port to a trusted port.

[H3C-Ethernet1/0/1] dhcp-snooping trust

1.1.3  display dhcp-snooping

Syntax

display dhcp-snooping [ unit unit-id ]

View

Any view

Parameter

unit unit-id: Displays the DHCP-snooping information on other devices in fabric when the switch is in fabric. unit-id indicates the number of the device whose DHCP-snooping information needs to be viewed.

Description

Use the display dhcp-snooping command to display the user IP-MAC address mapping entries recorded by the DHCP snooping function.

Related command: dhcp-snooping.

Example

# Display the user IP-MAC address mapping entries recorded by the DHCP snooping function.

<H3C> display dhcp-snooping

DHCP-Snooping is enabled.

The client binding table for all untrusted ports.     

 Type : D--Dynamic , S--Static

 Unit ID : 1

 Type IP Address      MAC Address     Lease     VLAN Interface

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

---   0 dhcp-snooping item(s) of unit 1 found   ---

1.1.4  display dhcp-snooping trust

Syntax

display dhcp-snooping trust

View

Any view

Parameter

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 command: dhcp-snooping trust.

Example

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

<H3C> display dhcp-snooping trust

DHCP-Snooping is enabled.

 DHCP-Snooping trust become effective.

 Interface                 Trusted

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

 Ethernet1/0/10         Trusted 

The above display information indicates that the DHCP snooping function is enabled, and the Ethernet1/0/10 port is a trusted port.

 

Chapter 2  DHCP/BOOTP Client Configuration

2.1  DHCP Client Configuration Commands

2.1.1  debugging dhcp client

Syntax

debugging dhcp client { all | error | event | packet }

undo debugging dhcp client { all | error | event | packet }

View

User view

Parameter

all: Enables all types of debugging for dynamic host configuration protocol (DHCP) or bootstrap protocol (BOOTP) client.

error: Enables debugging for DHCP/BOOTP client error messages (including the information about unidentified packets).

event: Enables debugging for DHCP/BOOTP client events (including address allocation and data update).

packet: Enables debugging for packets received/transmitted by a DHCP/BOOTP client.

Description

Use the debugging dhcp client command to enable a specified type of debugging for the DHCP/BOOTP client.

Use the undo debugging dhcp client command to disable debugging output.

By default, debugging for DHCP/BOOTP client is disabled.

As debugging occupies system resources, disable debugging if it is not needed.

Example

# Enable debugging for DHCP/BOOTP client events.

<H3C> debugging dhcp client event

2.1.2  debugging dhcp irf xha

Syntax

debugging dhcp irf xha

undo debugging dhcp irf xha

View

User view

Parameter

None

Description

Use the debugging dhcp irf xha command to enable the hot backup debugging for the DHCP/BOOTP client.

Use the undo debugging dhcp irf xha command to disable the hot backup debugging for the DHCP/BOOTP client.

The hot backup debugging for the DHCP/BOOTP client is disabled by default.

Example

# Enable the hot backup debugging for the DHCP/BOOTP client.

<H3C> debugging dhcp irf xha

2.1.3  display dhcp client

Syntax

display dhcp client [ verbose ]

View

Any view

Parameter

verbose: Displays the detailed address allocation information.

Description

Use the display dhcp client command to display the information about the address allocation of DHCP clients.

Example

# Display the information about the address allocation of DHCP clients.

<H3C> display dhcp client verbose

DHCP client statistic information:

Vlan-interface1:

Current machine state: BOUND

Allocated IP: 169.254.0.2 255.255.0.0

Allocated lease: 86400 seconds, T1: 43200 seconds, T2: 75600 seconds

Lease from 2002.09.20 01:05:03   to   2002.09.21 01:05:03

Server IP: 169.254.0.1

Transaction ID = 0x3d8a7431

Default router: 2.2.2.2

Next timeout will happen after 0 days 11 hours 56 minutes 1 seconds.

The output information above shows that:

l           The IP address 169.254.0.2/16 is allocated to VLAN interface1.

l           The current state of the client state machine is BOUND.

l           The lease period of the address is 86,400 seconds.

l           The value of the renewal timer and rebinding timer is 43,200 seconds and 75,600 seconds.

l           The lease period dates from 2002.09.20 01:05:03 to 2002.09.21 01:05:03.

l           The IP address of the DHCP server is 169.254.0.1.

l           The IP address of the gateway is 2.2.2.2.

l           Next timeout will happen after 11 hours 56 minutes 1 second.

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

Field	Description
Vlan-interface1	VLAN interface operating as a DHCP client to obtain an IP address dynamically
Current machine state	The state of the client state machine
Allocated IP	IP address allocated to the DHCP client
lease	Lease period
T1	Renewal timer setting
T2	Rebinding timer setting
Lease from….to….	The starting and end time of the lease period
Server IP	IP address of the DHCP server selected
Transaction ID	Transaction ID
Default router	Gateway address

 

2.1.4  ip address dhcp-alloc

Syntax

ip address dhcp-alloc

undo ip address dhcp-alloc

View

VLAN interface view

Parameter

None

Description

Use the ip address dhcp-alloc command to configure a VLAN interface to obtain an IP address through DHCP.

Use the undo ip address dhcp-alloc command to cancel the configuration.

By default, a VLAN interface does not use DHCP to obtain an IP address.

Example

# Configure the management VLAN interface to obtain an IP address through DHCP. (Assume that VLAN 1 is the management VLAN.)

<H3C> system-view

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

[H3C] interface Vlan-interface 1

[H3C-Vlan-interface1] ip address dhcp-alloc

2.2  BOOTP Client Configuration Commands

2.2.1  display bootp client

Syntax

display bootp client [ interface Vlan-interface vlan-id ]

View

Any view

Parameter

vlan-id: ID of the management VLAN interface.

Description

Use the display bootp client command to display BOOTP client-related information, including the MAC address of the BOOTP client and the IP address obtained.

Example

# Display the BOOTP client-related information.

<H3C> display bootp client interface Vlan-interface 1

Vlan-interface1:

Allocated IP: 169.254.0.2 255.255.0.0

Transaction ID = 0x3d8a7431

Mac Address  00e0-fc0a-c3ef

Table 2-2 Description on the fields of the display bootp client command

Field	Description
Vlan-interface1	Management VLAN interface 1 is configured to obtain an IP address through BOOTP.
Allocated IP	IP address allocated to the VLAN interface
Transaction ID	Value of the XID field in BOOTP packets
Mac Address	MAC address of the BOOTP client

 

2.2.2  ip address bootp-alloc

Syntax

ip address bootp-alloc

undo ip address bootp-alloc

View

VLAN interface view

Parameter

None

Description

Use the ip address bootp-alloc command to configure a VLAN interface to obtain an IP address through BOOTP.

Use the undo ip address bootp-alloc command to cancel the configuration.

By default, a VLAN interface does not use BOOTP to obtain an IP address.

Related command: display bootp client.

Example

# Configure the management VLAN interface to obtain an IP address through BOOTP. (Assume that VLAN 1 is the management VLAN.)

<H3C> system-view

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

[H3C] interface Vlan-interface 1

[H3C-Vlan-interface1] ip address bootp-alloc