Configuration Guide

Table Of Contents
VSP 4000/7200/8000 release 5.0 or higher – redistribution of ISIS into OSPF and vise-
versa using External Metrics
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October 2021
123
Please note the following:
The ISIS metric type of external can be used instead of internal type
o
Prefix cost (external metric) with lowest cost will be preferred and if prefix cost is the
same, the routes are considered ECMP routes
A route-map can be used to specify metric type of none, internal or external; for example, a route-
map can be used to selectively set specific routes as external
When deciding which routes to add to the route table, a SPB router
o
Internal type routes
Always preferred over External type routes
Will always prefer the routes with the shortest path internal metric to the BEB
node advertising them
Will only use the route external cost (prefix-cost) as a tie breaker
configure terminal
no ip alternative-route
route-map "reject" 1
no permit
match metric-type-isis external
enable
exit
router ospf
as-boundary-router enable
redistribute isis
redistribute isis enable
exit
router isis
accept adv-rtr 0.90.01
accept adv-rtr 0.90.01 route-map "reject"
accept adv-rtr 0.90.01 enable
redistribute ospf
redistribute ospf metric-type external
redistribute ospf enable
exit
isis apply accept
isis apply redistribute ospf
ip ospf apply redistribute isis
configure terminal
no ip alternative-route
route-map "reject" 1
no permit
match metric-type-isis external
enable
exit
router ospf
as-boundary-router enable
redistribute isis
redistribute isis enable
exit
router isis
accept adv-rtr 0.90.02
accept adv-rtr 0.90.02 route-map "reject"
accept adv-rtr 0.90.02 enable
redistribute ospf
redistribute ospf metric-type external
redistribute ospf enable
exit
isis apply accept
isis apply redistribute ospf
ip ospf apply redistribute isis