Users Guide

area area-id virtual-link router-id [hello-interval seconds | retransmit-interval seconds
| transmit-delay seconds | dead-interval seconds | authentication-key key | message-
digest-key keyid md5 key]
– area ID: assigned earlier (the range is from 0 to 65535 or A.B.C.D).
– 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).
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Open Shortest Path First (OSPFv2)