To manage an Ethernet switch remotely
through Telnet or the built-in Web server, the switch need to be assigned an IP
address. On H3C S5600 series Ethernet swithes, you can specify a management
VLAN through related command.
The management VLAN interface of a switch can
obtain an IP address in one of the following three ways:
l
Through the command used to configure IP address
l
Through BOOTP (In this case, the switch operates
as a BOOTP client.)
l
Through dynamic host configuration protocol (DHCP)
(In this case, the switch operates as a DHCP client)
The latest IP address obtained overwrites
the previous one. That is, the latest IP address obtained causes the previously
IP address to be released. For example, if you assign an IP address to a VLAN
interface by using the corresponding commands and then apply for another IP
address through BOOTP (using the ip address bootp-alloc command), the
former IP address will be released, and the final IP address of the VLAN interface
is the one obtained through BOOTP.
A static route is configured manually by an
administrator. You can make a network with relatively simple topology to
operate properly by simply configuring static routes for it. Configuring and using
static routes wisely helps to improve network performance and can guarantee
bandwidth for important applications.
The disadvantages of static route lie in
that: When a fault occurs or the network topology changes, static routes may
become unreachable, which in turn results in network failures. In this case,
manual configurations are needed to recover the network.
To access an S5600 series Ethernet switch
through networks, you can configure static routes for it.
1.2 Management VLAN Configuration
Before configuring the management VLAN, make
sure the VLAN operating as the management VLAN exists. If VLAN 1 (the default
VLAN) is the management VLAN, just go ahead.
Table 1-1 Configure
the management VLAN
|
Operation
|
Command
|
Description
|
|
Enter system view
|
system-view
|
—
|
|
Configure a specified VLAN to be the
management VLAN
|
management-vlan vlan-id
|
Required
By default, VLAN 1 operates as the
management VLAN.
|
|
Configure the default route
|
ip route-static 0.0.0.0 0.0.0.0 { null null-interface-number | next-hop
} [ preference preference-value ] [ reject | blackhole
] [ detect-group detect-group-id ] [ description text
]
|
Required
|
|
Create the management VLAN interface and
enter the corresponding VLAN interface view
|
interface vlan-interface vlan-id
|
Required
|
|
Assign an IP address to the management
VLAN interface
|
ip address
ip-address mask [ sub ]
|
Required
By default, the management VLAN interface
has no IP address.
|
|
Provide a description string for the
management VLAN interface
|
description string
|
Optional
By default, the description string of the
management VLAN interface is “Vlan-interface vlan-id Interface”.
|
|
Shut down
the management VLAN interface
|
shutdown
|
Optional
By
default, a management VLAN interface is down if all the Ethernet ports in the
management VLAN are down; a management VLAN interface is up if one or more
Ethernet ports in the management VLAN are up.
|
|
Bring up
the management VLAN interface
|
undo
shutdown
|
Caution:
l
To configure the management VLAN of a switch operating
as a cluster management device to be a cluster management VLAN (using the management-vlan
vlan-id command) successfully, make sure the vlan-id argument
provided in the management-vlan vlan-id command is consistent
with that of the management VLAN.
l
Bringing up or shutting down a management VLAN
interface has no effect on the up/down status of the Ethernet ports in the
management VLAN.
I. Network requirements
To manage
the switch SwitchA remotely through Telnet, These requirements are to be met: SwitchA
has an IP address, and the route between SwitchA and the remote console is reachable.
You need to configure the switch as
follows:
l
Assigning an IP address to the management VLAN
interface
l
Configuring the default route
II. Configuration procedure
# Enter system view.
<H3C> system-view
# Create VLAN 10 and configure VLAN 10 to
be the management VLAN.
[H3C] vlan 10
[H3C-vlan10] quit
[H3C] management-vlan 10
# Create the VLAN 10 interface and enter
VLAN interface view.
[H3C] interface vlan-interface 10
# Configure the IP address of VLAN 10 interface
to be 1.1.1.1.
[H3C-Vlan-interface10] ip address
1.1.1.1 255.255.255.0
[H3C-Vlan-interface10] quit
# Configure the default route.
[H3C] ip route-static 0.0.0.0 0.0.0.0
1.1.1.2
Table 1-2 Display
management VLAN configuration
|
Operation
|
Command
|
Description
|
|
Display the IP-related information about a
management VLAN interface
|
display ip interface [ brief [ Vlan-interface [ vlan-id ] ]
| [ Vlan-interface vlan-id ] ]
|
Optional
You can execute the display
commands in any view.
|
|
Display the information about a management
VLAN interface
|
display interface
vlan-interface [ vlan-id ]
|
|
Display summary information about the routing
table
|
display ip routing-table
|
|
Display detailed information about the routing
table
|
display ip routing-table verbose
|
|
Display the routes leading to a specified
IP address
|
display ip routing-table ip-address [ mask ] [ longer-match
] [ verbose ]
|
|
Display the routes leading to a specified
IP address range
|
display ip routing-table ip-address1 mask1 ip-address2 mask2 [
verbose ]
|
|
Display the routing information of the
specified protocol
|
display ip routing-table protocol protocol [ inactive | verbose ]
|
|
Display the routing table in a tree structure
|
display ip routing-table radix
|
|
Display the statistics on the routing
table
|
display ip routing-table statistics
|
As the network scale expands and the
network complexity increases, the network configurations become more and more
complex accordingly. It is usually the case that the computer locations change
(such as the portable computers in wireless networks) or the number of the
computers exceeds that of the available IP addresses. The dynamic host
configuration protocol (DHCP) is developed to meet these requirements. DHCP adopts
the client/server model, where DHCP clients request DHCP servers dynamically
for configuration information, and the DHCP servers in turn return
corresponding configuration information based on policies.
A typical DHCP implementation usually
involves a DHCP server and multiple clients (such as PCs and portable computers),
as shown in Figure 2-1.
Figure 2-1 A typical DHCP implementation
The interactions between a DHCP client and a
DHCP server are shown in Figure 2-2.
Figure 2-2
The interaction between a DHCP client and a DHCP server
To obtain a valid IP address dynamically, a
DHCP client exchanges different information with the DHCP server in different
phases. Usually, the following three phases are involved.
1)
The DHCP client accesses the network for the
first time
When a DHCP client accesses a network for
the first time, it goes through the following four phases to establish
connections with the DHCP server.
l
Discovery. The DHCP client tries to discover a
DHCP server by broadcasting DHCP_Discover packets in the network. Only DHCP
servers respond to this type of packets.
l
Offering IP addresses. Upon receiving
DHCP_Discover packets, each DHCP server selects a free IP address from an
address pool and sends a DHCP_Offer packet that carries the selected IP address
and other configuration information to the DHCP client.
l
Selecting the IP address to be used. The DHCP
client only accepts and processes the first-arrived DHCP_Offer packet (if multiple
DHCP servers send DHCP_Offer packets to it), and broadcasts a DHCP_Request
packet to each DHCP server. The packet contains the IP address carried in the DHCP_Offer
packet the DHCP client receives.
l
Acknowledgement. Upon receiving the DHCP_Request
packet, the DHCP server that owns the IP address carried in the DHCP_Request
sends a DHCP_ACK packet to the DHCP client. The packet contains the IP address
offered and other configuration information. The DHCP client binds TCP/IP
protocol components to its MAC address after receiving the packet.
IP addresses offered by other DHCP servers
(if any) through DHCP_Offer packets but not selected by the DHCP client are
still available for other clients.
2)
The DHCP client accesses the network for the
second and the followed time
In this case, the DHCP client establishes
connections with the DHCP server through the following steps.
l
After accessing the network successfully for the
first time, the DHCP client can access the network again by broadcasting a
DHCP_Request packet that contains the IP address assigned to it last time instead
of a DHCP_Discover packet.
l
Upon receiving the DHCP_Request packet and, when
the IP address applied by the client is available, the DHCP server that owns
the IP address responds with a DHCP_ACK packet to enable the DHCP client to use
the IP address again.
l
If the IP address is not available (for example,
it is assigned to another DHCP client), the DHCP server responds with a
DHCP_NAK packet, which enables the DHCP client to request for a new IP address
by sending a DHCP_Discover packet once again.
3)
The DHCP client extends the lease of an IP
address
IP addresses assigned dynamically are only valid
for a specified period of time and the DHCP servers reclaim their assigned IP
addresses at the expiration of these periods. Therefore, a DHCP client need to extend
the lease period if it is to use a dynamically assigned IP address for a period
longer than allowed.
By default, a DHCP client updates its IP
address lease automatically by sending DHCP_Request packets to the DHCP server
when half of the lease period expires. The DHCP server, in turn, responds with
a DHCP_ACK packet to notify the DHCP client of the new lease if the IP address
is still available. An S5600 series switch operating as a DHCP support this
lease auto-update process.
A BOOTP client can request the server for
an IP address through BOOTP. It goes through the following two phases to apply
for an IP address.
l
Sending a BOOTP request packet to the server
l
Processing the BOOTP response packet received from
the server
To obtain an IP address through BOOTP, a BOOTP
client first sends a BOOTP request packet to the server. Upon receiving the
request packet, the server returns a BOOTP response packet. The BOOTP client then
retrieves the assigned IP address from the response packet.
The BOOTP packets are sent using user
datagram protocol (UDP). To ensure reliable packet transmission, a timer is triggered
when a BOOTP client sends a request packet to the server. If no response packet
is received from the server after the timer times out, the client sends the
request packet again. BOOTP request packets are sent every five seconds and
three times at most. A BOOTP client stops sending BOOTP request packets if it
fails to obtain an IP address after sending three successive BOOTP request
packets.
An S5600 series Ethernet switch can operate
as a DHCP client or BOOTP client. In this case, the IP address of the
management VLAN interface is obtained through DHCP or BOOTP.
Before configuring the management VLAN, you
need to create the VLAN that is to act as the management VLAN. As VLAN 1 is the
default VLAN, there is no need to create it if you configure VLAN 1 to be the
management VLAN.
Table 2-1 Configure
a DHCP/BOOTP client
|
Operation
|
Command
|
Description
|
|
Enter system view
|
system-view
|
Required
|
|
Configure a specified VLAN to be the
management VLAN
|
management-vlan vlan-id
|
Required
By default, VLAN 1 operates as the
management VLAN.
|
|
Create the management VLAN interface and
enter VLAN interface view
|
interface vlan-interface vlan-id
|
Required
|
|
Configure the way in which the management
VLAN interface obtains an IP address
|
ip address
{ bootp-alloc | dhcp-alloc }
|
Required
By default, no IP address is assigned to the
management VLAN interface.
|
Caution:
Note that as a DHCP
client, an S5600 switch can occupy an IP address for up to 24 days. That is,
even if the lease period of the address pool on the DHCP server is longer than
24 days, the DHCP client can only obtain a 24-day lease.
I. Network requirements
To manage the switch SwitchA remotely,
which operates as a DHCP client, through Telnet, The following are required:
l
SwitchA obtains an IP address through DHCP
l
The route between SwitchA and the remote console
is reachable.
To achieve this, you need to perform the
following configuration for the switch:
l
Configuring the management VLAN interface to
obtain an IP address through DHCP
l
Configuring a default route
II. Configuration procedures
# Enter system view.
<H3C> system-view
# Create VLAN 10 and configure VLAN 10 to
be the management VLAN.
[H3C] vlan 10
[H3C-vlan10] quit
[H3C] management-vlan 10
# Create VLAN 10 interface and enter VLAN
interface view.
[H3C] interface vlan-interface 10
# Configure the management VLAN interface
to obtain an IP address through DHCP.
[H3C-Vlan-interface10] ip address
dhcp-alloc
[H3C-Vlan-interface10] quit
# Configure the default route.
[H3C] ip route-static 0.0.0.0 0.0.0.0
1.1.1.2
Table 2-2
Display the information about a DHCP/BOOTP client
|
Operation
|
Command
|
Description
|
|
Display the information about IP address
assignment on the DHCP client
|
display dhcp client [ verbose ]
|
Optional
You can execute the display
commands in any view.
|
|
Display the information about the BOOTP
client
|
display bootp client [ interface vlan-interface vlan-id ]
|
