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○ 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 configuration to create a virtual link.
Use EITHER the Authentication Key or the Message Digest (MD5) key.
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 filter routes, use prefix lists. OSPF applies prefix lists to incoming or outgoing routes.
Incoming routes must meet the conditions of the prefix lists. If they do not, OSPF does not add the route to the routing table.
Configure the prefix list in CONFIGURATION PREFIX LIST mode prior to assigning it to the OSPF process.
● Create a prefix list and assign it a unique name.
CONFIGURATION mode
ip prefix-list prefix-name
You are in PREFIX LIST mode.
● Create a prefix 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 prefix length to match (from 0 to 32).
○ le max-prefix-length: is the maximum prefix length to match (from 0 to 32).
For configuration information about prefix 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.
To redistribute routes, use the following command.
● Specify which routes are redistributed into OSPF process.
CONFIG-ROUTEROSPF-id mode
redistribute {bgp | connected | isis | rip | static} [metric metric-value | metric-type
type-value] [route-map map-name] [tag tag-value]
Configure the following required and optional parameters:
○ bgp, connected, isis, rip, static: enter one of the keywords to redistribute those routes.
○ metric metric-value: the range is from 0 to 4294967295.
○ metric-type metric-type: 1 for OSPF external route type 1. 2 for OSPF external route type 2.
Open Shortest Path First (OSPFv2)
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