Alcatel-Lucent 7750 SR-OS, Configuration Manual

Page: 36 / 674

Configuring IP Router Parameters
Page 36 7750 SR OS Router Configuration Guide
Router ID
The router ID, a 32-bit number, uniquely identifies the router within an autonomous system (AS)
(see
Autonomous Systems (AS) on page 37 ). In protocols such as OSPF, routing information is
exchanged between areas, groups of networks that share routing information. It can be set to be the
same as the loopback address. The router ID is used by both OSPF and BGP routing protocols in
the routing table manager instance.
There are several ways to obtain the router ID. On each router, the router ID can be derived in the
following ways.
• Define the value in the config>router router-id context. The value becomes the router ID.
• Configure the system interface with an IP address in the config>router>interface ip-int-
name context. If the router ID is not manually configured in the config>router router-id
context, then the system interface acts as the router ID.
• If neither the system interface or router ID are implicitly specified, then the router ID is
inherited from the last four bytes of the MAC address.
• The router can be derived on the protocol level; for example, BGP.