folks
if i have two isp connections passing a default route to my routers and i want to set up a failover environment
how do i pass both default routes to my routers but mark one as the preferred route and the other as a less preferred route, i.e. metric 0 and metric 10
do i use 'set metric' and a route map?
i'd be grateful to anyone with a related config
thanks to anyone taking the time to respond and apolgies if i'm a bit vague or lacking sufficient detail
Solved! Go to Solution.
Hello,
If they are eBGP, and you are the customer, you can use the local-preference to set a preferred route.
Would be something like that:
access-list 10 permit 0.0.0.0 OR ip prefix-list default permit 0.0.0.0/0
route-map default-route permit 10
match ip address 10 OR match ip prefix-list default
set local-preference 200
router bgp
neighbor <preferred neighbor> route-map default-route in
If you are the provider, as you said, you can use the metric. the only thing that would change is on the route-map, would be "set metric X", where this metric would be a valuer higher than the preferred route's metric.
Then do a soft reset and this should be good.
Regards,
Bruno Silva.
Hello,
If they are eBGP, and you are the customer, you can use the local-preference to set a preferred route.
Would be something like that:
access-list 10 permit 0.0.0.0 OR ip prefix-list default permit 0.0.0.0/0
route-map default-route permit 10
match ip address 10 OR match ip prefix-list default
set local-preference 200
router bgp
neighbor <preferred neighbor> route-map default-route in
If you are the provider, as you said, you can use the metric. the only thing that would change is on the route-map, would be "set metric X", where this metric would be a valuer higher than the preferred route's metric.
Then do a soft reset and this should be good.
Regards,
Bruno Silva.
bruno
many thanks for your reply
i'll run this on gns and test it out
Do you mean pass the default-routes from your BGP routers to your internal routers ? If so what routing protocol are you running between your BGP routers and the interior routers.
Or do you mean make one BGP router the preferred path once the traffic has arrived at the BGP routers ?
Jon
jon
thanks for helping out
my problem is how should i pass the default route from my routers peering with the ISP to the routers below as the less favourable route so i can force traffic out my primary link
if the primary link fails then the less preferred route should move from the bgp table into the routing table
sorry if i'm confusing things
thanks
Hi Mul,
I assume you have setup as above and there is IBGP between R1 and R2 along with HSRP for high availability, you dont have to redistribute those defaults in your IGP.
Consider R1 is HSRP Active.
Now R1's BGP table will have 2 prefixes for the default route.
1. EBGP prefix
2. IBGP Prefix
Now, if BGP on R1 fails, packets would automatically take path via R2.
Hope it was useful.
Ameya
ameya
many thanks for your reply
i resolved the issue using the bgp default local-preference 150 command
i only needed to influence my own AS group so the local-preference command seemed the best option
thanks to everyone who replied and my apologies if i confused or didn't clarify the issues