I need to understand the OSPF metric and have a level of confusion which I am hoping someone can clarify for me?
We have our MPLS WAN redistributing all the routes from BGP into OSPF
CE Router:
router ospf 1
log-adjacency-changes
redistribute bgp 64993 subnets
On my WAN switch (connected to CE router) I have a network 10.188.3.0 which shows as below.
O E2 10.188.3.0/24 [110/1] via 10.251.251.98, 00:00:54, FastEthernet1/0
According to my knowledge this has a Distance of 110 (OSPF) and a metric of 1 (Not exactly sure what this means?)
We also have a bakckup link which I want to affect traffic to go over.
So I make this change
CE Router:
router ospf 1
log-adjacency-changes
redistribute bgp 64993 subnets route-map BGP_to_OSPF
Currently the route-map does not exist??
But his happens on WAN switch
*Mar 1 18:18:47.235: RT: del 10.188.3.0/24 via 10.251.251.98, ospf metric [110/1]
*Mar 1 18:18:47.235: RT: delete subnet route to 10.188.3.0/24
*Mar 1 18:18:47.235: RT: NET-RED 10.188.3.0/24
*Mar 1 18:18:47.235: RT: NET-RED queued, Queue size 1
*Mar 1 18:18:47.235: RT: add 10.188.3.0/24 via 10.251.251.209, ospf metric [110/20]
*Mar 1 18:18:47.235: RT: NET-RED 10.188.3.0/24
Now sh ip route on WAN Switch shows this
O E2 10.188.3.0/24 [110/20] via 10.251.251.209, 00:01:45, FastEthernet0/0
It is now taking a different path because metric is now 20?
Why does redistributing with a route-map statement that does not exist cause this behaviour?
Many Thanks
Roger
