Users Guide

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
Dell(conf)#router ospf 10
Dell(conf-router_ospf)#log-adjacency-changes
Dell(conf-router_ospf)#network 4.1.1.0/24 area 0
Dell(conf-router_ospf)#network 1.1.1.0/24 area 1
Dell(conf-router_ospf)#max-metric router-lsa on-startup wait-for-
bgp
Dell(conf-router_ospf)#exit
Dell(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
Dell(conf)#show ip ospf database router
Exception Flag: Announcing maximum link costs
LS age: 198
Open Shortest Path First (OSPFv2 and OSPFv3) 1317