Brocade TurboIron 24X Series Configuration Guide - Manual (Page 704)

670 Brocade TurboIron 24X Series Configuration Guide
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Basic configuration tasks
NOTE
Layer 3 Switches use the same router ID for both OSPF and BGP4. If the router is already configured
for OSPF, you may want to use the router ID that is already in use on the router rather than set a new
one. To display the router ID, enter the show ip CLI command at any CLI level.
To change the router ID, enter a command such as the following.
TurboIron(config)#ip router-id 10.157.22.26
Syntax: ip router-id <ip-addr>
The <ip-addr> can be any valid, unique IP address.
NOTE
You can specify an IP address used for an interface on the Layer 3 Switch, but do not specify an IP
address in use by another device.
Setting the local AS number
The local AS number identifies the AS the BGP4 router is in. The AS number can be from 1 –
65535. There is no default. AS numbers 64512 – 65535 are the well-known private BGP4 AS
numbers and are not advertised to the Internet community.
To set the local AS number, enter commands such as the following.
TurboIron(config)#router bgp
BGP4: Please configure 'local-as' parameter in order to enable BGP4.
TurboIron(config-bgp-router)#local-as 10
TurboIron(config-bgp-router)#write memory
Syntax: [no] local-as <num>
The <num> parameter specifies the local AS number.
Adding a loopback interface
You can configure the router to use a loopback interface instead of a specific port or virtual routing
interface to communicate with a BGP4 neighbor. A loopback interface adds stability to the network
by working around route flap problems that can occur due to unstable links between the router and
its neighbors.
Loopback interfaces are always up, regardless of the states of physical interfaces. Loopback
interfaces are especially useful for IBGP neighbors (neighbors in the same AS) that are multiple
hops away from the router. When you configure a BGP4 neighbor on the router, you can specify
whether the router uses the loopback interface to communicate with the neighbor. As long as a
path exists between the router and its neighbor, BGP4 information can be exchanged. The BGP4
session is not associated with a specific link but instead is associated with the virtual interfaces.
You can add up to 24 IP addresses to each loopback interface.
NOTE
If you configure the Layer 3 Switch to use a loopback interface to communicate with a BGP4
neighbor, the peer IP address on the remote router pointing to your loopback address must be
configured.
To add a loopback interface, enter commands such as those shown in the following example.