Brocade Communications Systems Layer 3 Routing Configuration ICX 6650 - Manual (Page 49)

Brocade ICX 6650 Layer 3 Routing Configuration Guide 31
53-1002603-01
Configuring IP parameters – Layer 3 Switches
Changing the router ID
In most configurations, a Layer 3 Switch has multiple IP addresses, usually configured on different
interfaces. As a result, a Layer 3 Switch identity to other devices varies depending on the interface
to which the other device is attached. Some routing protocols, including Open Shortest Path First
(OSPF) and Border Gateway Protocol version 4 (BGP4), identify a Layer 3 Switch by just one of the
IP addresses configured on the Layer 3 Switch, regardless of the interfaces that connect the Layer
3 Switches. This IP address is the router ID.
NOTE
Routing Information Protocol (RIP) does not use the router ID.
NOTE
If you change the router ID, all current BGP4 sessions are cleared.
By default, the router ID on a Brocade Layer 3 Switch is one of the following:
• 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 192.168.9.9/24:
- Loopback interface 1, 192.168.9.9/24
- Loopback interface 2, 192.168.4.4/24
- Loopback interface 3, 192.168.1.1/24
• If the device does not have any loopback interfaces, the default router ID is the lowest
numbered IP interface configured on the device.
If you prefer, you can explicitly set the router ID to any valid IP address. The IP address cannot be in
use on another device in the network.
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 command at any CLI level.
To change the router ID, enter a command such as the following.
Brocade(config)# ip router-id 192.168.22.26
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.
Specifying a single source interface for specified
packet types
When the Layer 3 Switch originates a packet of one of the following types, the source address of
the packet is the lowest-numbered IP address on the interface that sends the packet:
• Telnet