ECS4660-28F_Management Guide-R03

C HAPTER 51 | IP Routing Commands
Open Shortest Path First (OSPFv2)
– 1774 –
packets. Neighbor routers must use the same key identifier and key
value.
◆ When changing to a new key, the router will send multiple copies of all
protocol messages, one with the old key and another with the new key.
Once all the neighboring routers start sending protocol messages back
to this router with the new key, the router will stop using the old key.
This rollover process gives the network administrator time to update all
the routers on the network without affecting the network connectivity.
Once all the network routers have been updated with the new key, the
old key should be removed for security reasons.
EXAMPLE
This example sets a message-digest key identifier and password.
Console(config)#interface vlan 1
Console(config-if)#ip ospf message-digest-key 1 md5 aiebel
Console(config-if)#
RELATED COMMANDS
ip ospf authentication (1769)
ip ospf priority This command sets the router priority used when determining the
designated router (DR) and backup designated router (BDR) for an area.
Use the no form to restore the default value.
SYNTAX
ip ospf [ip-address] priority priority
no ip ospf [ip-address] priority
ip-address - This parameter can be used to indicate a specific IP
address connected to the current interface. If not specified, the
command applies to all networks connected to the current interface.
priority - Sets the interface priority for this router. (Range: 0-255)
COMMAND MODE
Interface Configuration (VLAN)
DEFAULT SETTING
1
COMMAND USAGE
◆ A designated router (DR) and backup designated router (BDR) are
elected for each OSPF network segment based on Router Priority. The
DR forms an active adjacency to all other routers in the network
segment to exchange routing topology information. If for any reason
the DR fails, the BDR takes over this role.