Users Guide

– router ID: IP address associated with the virtual link neighbor.
– hello interval seconds: the range is from 1 to 8192 (the default is 10).
– retransmit interval seconds: the range is from 1 to 3600 (the default is 5).
– transmit delay seconds: the range is from 1 to 3600 (the default is 1).
– dead interval seconds: the range is from 1 to 8192 (the default is 40).
– authentication key: eight characters.
– message digest key keyid: the range is from 1 to 255.
– md5 key: 16 characters.
If you do not enter other parameters, the defaults are used.
Only the area ID and router ID require conguration to create a virtual link.
Use EITHER the Authentication Key or the Message Digest (MD5) key.
Example of Viewing Virtual Links
Use the show ip ospf process-id virtual-links command to view the virtual link.
Dell#show ip ospf 1 virtual-links
Virtual Link to router 192.168.253.5 is up
Run as demand circuit
Transit area 0.0.0.1, via interface TenGigabitEthernet 13/16, Cost of using 2
Transmit Delay is 1 sec, State POINT_TO_POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
Hello due in 00:00:02
Dell#
Creating Filter Routes
To lter routes, use prex lists. OSPF applies prex lists to incoming or outgoing routes.
Incoming routes must meet the conditions of the prex lists. If they do not, OSPF does not add the route to the routing table.
Congure the prex list in CONFIGURATION PREFIX LIST mode prior to assigning it to the OSPF process.
• Create a prex list and assign it a unique name.
CONFIGURATION mode
ip prefix-list prefix-name
You are in PREFIX LIST mode.
• Create a prex list with a sequence number and a deny or permit action.
CONFIG- PREFIX LIST mode
seq sequence-number {deny |permit} ip-prefix [ge min-prefix-length] [le max-prefix-
length]
The optional parameters are:
– ge min-prefix-length: is the minimum prex length to match (from 0 to 32).
– le max-prefix-length: is the maximum prex length to match (from 0 to 32).
For conguration information about prex lists, refer to Access Control Lists (ACLs).
Redistributing Routes
You can add routes from other routing instances or protocols to the OSPF process.
With the redistribute command, you can include RIP, static, or directly connected routes in the OSPF process.
NOTE: Do not route iBGP routes to OSPF unless there are route-maps associated with the OSPF redistribution.
614
Open Shortest Path First (OSPFv2)