Setup Guide

Version Description
9.1.(0.0) Introduced on the S4810 and Z9000.
8.4.2.5 Introduced on C-Series and E-Series TeraScale.
8.4.1.3 Introduced on E-Series ExaScale.
Usage
Information
When you bring a new router onto an OSPF network, you can configure the router to function as a stub
router by globally reconfiguring the OSPF link cost so that other routers do not use a path that forwards
traffic destined to other networks through the new router for a specified time until the router’s switching
and routing functions are up and running, and the routing tables in network routers have converged.
By using the max-metric router-lsa command, you force the link cost of all OSPF non-stub links to the
maximum link cost (65535). The advertisement of this maximum metric causes other routers to assign a
cost to the new router that is higher than the cost of using an alternate path. Because of the high cost
assigned to paths that pass through the new router, other routers will not use a path through the router
as a transit path to forward traffic to other networks.
Use the max-metric router-lsa command to gracefully shut down or reload a router without dropping
packets destined for other networks.
NOTE: If you enter the max-metric router-lsa command without an option (on-startup announce-
time or on-startup wait-for-bgp [wait-time]), the maximum metric of 65535 is always announced
in LSAs sent by the router.
Example
max-metric router-lsa
DellEMC(conf)#router ospf 10
DellEMC(conf-router_ospf)#log-adjacency-changes
DellEMC(conf-router_ospf)#network 4.1.1.0/24 area 0
DellEMC(conf-router_ospf)#network 1.1.1.0/24 area 1
DellEMC(conf-router_ospf)#max-metric router-lsa on-startup wait-for-bgp
DellEMC(conf-router_ospf)#exit
DellEMC(conf)#show ip ospf
Routing Process ospf 10 with ID 100.1.1.1 Virtual router default-vrf
Supports only single TOS (TOS0) routes
It is an Area Border Router
Originating router lsas with maximum metric
Time remaining 00:07:07
Condition : On-Startup while BGP is converging for 600 secs. State :
Active
SPF schedule delay 5 secs, Hold time between two SPFs 10 secs
Convergence Level 0
Min LSA origination 5 secs, Min LSA arrival 1 secs
Number of area in this router is 2, normal 2 stub 0 nssa 0
Area BACKBONE (0)
Number of interface in this area is 1
SPF algorithm executed 3 times
Area ranges are
Area 1
Number of interface in this area is 1
SPF algorithm executed 3 times
Area ranges are
DellEMC(conf)#show ip ospf database router
Exception Flag: Announcing maximum link costs
LS age: 198
Options: (No TOS-capability, DC)
LS Type: Router Links
Link State ID: 2.1.1.1
Advertising Router: 2.1.1.1
LS Seq Number: 80000005
Checksum: 0x9F5D
Length: 48
Number of Links: 2
Open Shortest Path First (OSPFv2 and OSPFv3)
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