Changing the router ID number in the config>routercontext causes the new value to overwrite the router ID configured on the protocol level, system interface level, or the value inherited from the MAC address. Changing the router ID on a router could cause configuration inconsistencies if associated values are not also modified.
When configuring a new router ID, protocols are not automatically restarted with the new router ID. The next time a protocol is (re) initialized the new router ID is used. An interim period of time can occur when different protocols use different router IDs. To force the new router ID, issue the shutdown and no shutdown commands for each protocol that uses the router ID or restart the entire router.
Use the following syntax to change a router ID.
config>router# router-id router-id
config>router# router-id 10.10.10.104
config>router# no shutdown
config>router>bgp# shutdown
config>router>bgp# no shutdown
ALA-A>config>router# info
#------------------------------------------
# IP Configuration
#------------------------------------------
interface "system"
address 10.10.10.104/32
exit
interface "to-103"
address 10.0.0.104/24
port 1/1/1
exit
autonomous-system 100
router-id 10.10.10.104
#------------------------------------------
ALA-B>config>router#