Guys i have been reading about Local Preference. Wanted to clear my scenario. Input will be appreciated. Following is the
Sorry guys, LINES SHOULD BE SHOWING TO BE CONNECTED FROM R2 TO R4. Can't seem to create a straight line between R2 and R4
R-1 and R-2 both are running IBGP (Same AS).
R-3 and R-4 are running IBGP.
R-1 is connected to R-3 ( EBGP Connection)
R-2 is connected to R-4 ( EBGP connection).
Now the scenario is R-3 and R-4 both are sending the same set of Networks towards R1 and R2 respectively for eg (10.10.10.0/24). As the above connection is showing through EBGP.
What i want to acheive is What ever network R4 is sending towards R2. I want R-2 to access it going through R-1 and then to R-3. The networks coming from R-4 to R-2 i wanted to leave as it is with route-maps, just incase R-1 and R-2 connection goes down then R-2 has a way of knowing as to how to get to 10.10.10.0/24.
Let's say R-3 is sending 10.10.10.0/24 to R-1 and R-4 is sending 10.10.10.0/24 to R-2.
When i use Route-map on R-2, my local preference should be like this correct me if i am wrong
route-map R1_to_R2_IN permit
match ip address R1_to_R2_IN
set local-preference 200 <---------------- This is correct or not
As you may know, higher local preference is preferred. Hence, set the local preference to a higher value for Route(s) learnt from R3 on R1 and to a lower value on R2 for route(s) learnt from R4. Thus, all your IBGP/Internal routers would choose the path via R1-->R3 as the preferred path to get to 10.10.10.0/24. Local preference attribute is applicable only within an AS and therefore, you don't have to worry about filtering it on outbound updates to EBGP peers.
You need a configuration like the one noted below.
You have put the Local-preference 200 on Router # 1 so that 10.10.10.0/24 is prioritized from Router # 3
When i create a BGP neighbor on Router # 2 and Router # 1. Don't i have to define that 10.10.10.0/24 network is allowed to come in from Router 1 into Router 2 (IBGP connection) as mentioned in my notes above, and hosts on Router # 2 wants to access 10.10.10.0/24 then due to High local preference use the Router # 1.
Unless, you are filtering any prefixes all routes should be advertised to all other BGP peers. I presume you don't want to filter anything you are learning from R1 and hence, there's no need to use route maps there. BGP table on R2 will have 2 paths for 10.10.10.0/24 and it will choose the one via R1 as the preferred path based on the higher local preference.
I do not want all routes to be advertised through R1 coming out of R2 and vice versa. That's why i am trying to control it through Route-maps.
Only those networks which R4 and R3 ( Same) are sending to R2 and R1 respectively. That's why i am putting a route-map on Router # 2 of networks which i wanted to learn from Router # 1 and saying if any hosts on Router # 2 wants to access this , then prefer this path. So in our example 10.10.10.0/24 i have put it in route-map in on Router # 2 coming from Router # 1 and have put a local-preference on it. So wouldn't this path will be prioritzed.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.