BGP with several ISP's

RouterOS Forwarding Protocols
1

Hello,

I have a situation with mikrotik which i can’t slove so i need a help.

I have a mikrotik with 3 ISP’s. i made BGP and get connected to first ISP nd it works fine, now when i get the new ISP’s i can’t even ping the peer IP from mikrotik, i think because it goe’s through the default gateway 0.0.0.0/0 which points to the first ISP peer address.

Is there a way to fix that out? how to tell mikrotik to use 0.0.0.0/0 for all internet traffic except the traffic which I try to send to other ISP? and/or how can I reach the other peer ip?

Regards.

2

Is it multihop or direct connection?
In first case you add static route to remote peer. In second case you do not need to do anything because connected route is used and problem is elsewhere.

3

My mikrotik is connected directly to all ISP’s.
My first ISP works fine.
The new (ISP 2) is my problem, i can’t ping ISP’s peer ip, neither the ISP ping’s my peer ip.
the default route is 0.0.0./0 to my first ISP’s peer.

4

if you have your WAN / Serial side IP’s configured correctly on both sides (your router & ISP # 2), then you should be able to ping the other side … (this would be a connected route, and thus not going via the routing table)…

If you are not able to do that, then you have a physical layer connectivity issue.

5

Thanks Faisali for your post.

I have a strange situaation as i said. let me present what i’m trying to do.

i have a cisco 6500 switch with bgp connectivity. another cisco 3550 L3 switch, and then mikrotik with BGP also.

ISP1—>6500---->3550----->mikrotik<------ISP1 again.

i have a bgp on my 6500 established to ISP1. then i made a vlan 100 to the mikrotik and send the peer ip to mikrotik through 3500, and trying to make a ibgp between 6500 and mikrotik.

i can ping mikrotik peer ip, and 6500 peer ip from the 3550 switch. but can’t ping between 6500 and mikrotik.

6

Faisali you were right. it was a cable problem, when i change it it just worked fine.

regards

7

Well I guess the problem is still apear.
I didn’t solve my problem.

It’s like This.

ISP#1 -----> Mikrotik ----> ISP#1

My mikrotik is in the middle, and connected to the same ISP twice, so at first interface, i can ping my ISP peer ip and have established BGP session, but on the other way, i have a problem that i can’t ping my ISP peer from other interface, so i can’t make a BGP session. i made an update for mikrotik to version 5.26 now and still have the same problem, in fact I have the same situation with 4 mikrotiks and the same scenario.
One location is working fine but i have a different ISP.
ISP#2 ----> mikrotik ----> ISP#1 and this is working fine.
Any idea’s ?


Regards.

8

Post your config… sounds like you may have something mis-configured.