Configuration Guide User guide

FastIron Configuration Guide 1353
53-1002494-02
Basic configuration tasks required for BGP4
• If the router has loopback interfaces, the default router ID is the IP address configured on the
lowest numbered loopback interface configured on the Layer 3 switch. For example, if you
configure loopback interfaces 1, 2, and 3 as follows, the default router ID is 9.9.9.9/24:
• Loopback interface 1, 9.9.9.9/24
• Loopback interface 2, 4.4.4.4/24
• Loopback interface 3, 1.1.1.1/24
• If the device does not have any loopback interfaces, the default router ID is the lowest
numbered IP interface address configured on the device.
NOTE
Brocade 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.
Brocade(config)#ip router-id 209.157.22.26
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 Brocade 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 Brocade BGP4 router is in. The AS number can be from 1
through 65535. There is no default. AS numbers 64512 through 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.
Brocade(config)#router bgp
BGP4: Please configure 'local-as' parameter in order to enable BGP4.
Brocade(config-bgp-router)#local-as 10
Brocade(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.