Hello Rene
Please update the lesson on BGP Conditional Advertising / Advertise MAP.
If already in the lesson list, Please share the URL/Link.
regards
Raj
Hello Raj
As far as I know, there is no material yet on BGP conditional advertising. If you would like to suggest a lesson idea, feel free to go to the following link and post your idea. Others on the forum may have also suggested a similar lesson, and you can vote on the lessons you would like to see on the site in the near future.
In the meantime, take a look at these two Cisco documentations that may help you in looking at this particular feature.
As well as some case studies that may help…
I hope this has been helpful!
Laz
Hi raj,
the whole idea of Conditional advertising you could easly find the materials online.
it is used to play a role in multihomed architecture where you will only advertise routes to 1 ISP, if the link faills then the router sees the link down and immediately change to advertise the routes to the 2nd ISP.
you achieve this behavior using route-map and you inherit the route-map into the advertise-map in the bgp command options
for example:
access-list 1 permit host 1.1.1.1
access-list 2 permit any - this command is only an example
route-map NEIGHBOR1 permit 10
match ip address 1
route-map MYROUTES permit 10
match ip address 2
router bgp 1
neighbor 2.2.2.2 advertise-map MYROUTES non-exist-map NEIGHBOR1
in the above configuration, the router will check it’s RIB (routing table) and search the host route of 1.1.1.1 as included in the NEIGHBOR1 route-map.
the “non-exist-map” feature will make that process and if the route doesnt exist, the router would advertise neighbor 2.2.2.2 the “MYROUTES” routes included in that route-map.
you could specify any network you want to advertise or in this case I want to advertise everything to neighbor 2.2.2.2.
if the non-exist-map find the route for host 1.1.1.1 then the router wouldn’t advertise anything that included in the “MYROUTES” route-map to neighbor 2.2.2.2.
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