• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 1136
  • Last Modified:

Running HSRP with BGP in dual homed multi-isp configuration

Hi..

My current setup is as follows: I have 2 7200's peering with two separate ISPs and i am running IBGP between the edge routers.

I am concerned that if the ethernet interface on any of the 7200 fails, will the ISP routers be informed that the route no longer exists and if so, can i run HSRP to track the ethernet interface, so that all the traffic gets routed over the second edge router.

Thanks in advance...

Hassan
0
babanmutum
Asked:
babanmutum
1 Solution
 
Scotty_ciscoCommented:
Hassan;

Your answer is if your router running BGP does not have an interface or a static route to the advertised network your router will not advertise the network. Hence your ISP should no longer advertise the network and everything will reconverge through the second ISP.  This does not solve your basic problem on best path selection I have answered that seperatly below.  for instance lets say you are advertising the 166.30.35.0/24 network and your Fastethernet on your primary router is 166.30.35.2 and the secondary router is 166.30.35.3 and you have no static route in any of the routers pointing to 166.30.35.0 when the fastehernet on the primary router fails all routes you are advertising for the 166.30.35.0; in that router only; get deleated from the routing table; and then the new routing table is re-advertised to your ISP minus the 166.30.35.0 network.

I had this exact same issue and the way I corrected may not work for you when it comes to best path selection.  I have 2 Fastethernet interfaces and used a crossover cable between the 2 routers between the second interfaces and created a new neigbor for both routers.  There is one Key thing that you must do if you do this however; that is in your Router BGP configuration make sure you issue this command "no synchronization".  This speeds up the process of routes updating especially if your ISP does not flush the routes.

0

Featured Post

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Tackle projects and never again get stuck behind a technical roadblock.
Join Now