10-17-2013 12:39 AM - edited 03-04-2019 09:20 PM
Hey All,
I configured Cisco 1941 Router with two WAN.
1. ISP_1 i configured with Dynamic routing protocol (BGP), and ISP_2 (VSAT) is VSAT IDU.
2. For ISP_2 we configured static router with 230 metric.
Now the problem i having, when sent packet to my remote network then it is going through ISP_1 but return packets are comming through ISP_2.
I cant understand what to do....please suggest..
10-17-2013 01:36 AM
Can you diagram the setup?
Thanks
10-17-2013 04:16 AM
Hey Devils,
this is the topology that im using.
10-17-2013 04:42 AM
It sounds like what is happening, is that, outbound, it's obviously taking the correct link. When the return traffic comes back, other BGP routers, are choosing the path through the other ISP. This can happen because of a veriety of different reasons.
Are you advertsing out any networks via BGP, or is this extra link, simply for redundancy. I'm assuming you're advertising different networks out.
If the above is true, then you will need to tell Internet BGP routers, that you have attributes that will make the second link undesirable, so that return traffic goes through ISP1.
The best way to accomplish this IMO, is my pre-pending your AS. So if your local AS is 100, other routers will see just [100], when being advertised out each network. You can pre-pend it by [100. 100. 100] through your second ISP, when advertising your networks, thereby making it less desirable, and return traffic will come through ISP1.
I'll take a look at the wireshark file, one I get to work, while drinking coffee unless someone beats me too it.
Hope this helped some
10-17-2013 04:53 AM
Hey john,
Im using second link for redundancy. As for that link configured only static route with 230 metric.
10-17-2013 07:00 AM
When you see the data coming back, on the redundant link, is this from the laptop user?
10-17-2013 05:10 PM
send us a traceroute mate, for the rest, Are you saying you have no BGP between your 2911 that connects you with CE_VSAT_IDU? In which case you will not be able to influence the upstream path, using AS path prepending.
In which case, you will probably have to liaise with your provider and re-iterate your requirements.
=============================
Please remember to rate useful posts, by clicking on the stars below.
=============================
10-19-2013 07:07 AM
Hey Dennis,
CE_VSAT_IDU is managed by ISP, they only provide me IP address for my use. Now i have two way to use it First one is i connect that link in switch and give each client(PC) manual IP address in rage of device(CE_VSAT_IDU) that is very hectic, Second one is terminate link in router and configure STATIC ROUTE with METRIC value.
I choose the second way and configuration that i done on router are correct. As we told our ISP after configuring CE_VSAT_IDU we are facing such problem that whenever user send data out to our network then it goes from primary path(MPLS) but when user receive data it comes from secondary ISP (CE_VSAT_IDU). After troubleshoot by ISP the problem get resolved. Now both path working fine.
ISP1(MPLS_VPN network) Service provider BSNL
ISP2(VSAT)Service provider BSNL
My worry is i want to know what was the issue is this. Because ISP don't share this issue with us.
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide