BGP Issue / Duplicate remote RouterID:

RouterOS Forwarding Protocols
1

Hello,

We are experiencing a very strange issue... If any one can shed some light, it would be great.

Background: We have more than a hand full of X-86 RouterOS Routers working as Edge Routers in different parts of our network, some of them with as many as 80-90 BGP Peering sessions (connecting to different peering exchanges).

We have one such router(i7 x-86) been operating for more then 6 months, with about 30 or more BGP peering sessions, chugging away perfectly fine...

Last week, we needed to bring up one more bgp peering session, but this time, when we try to bring the session up, we immediately get error message in the log.
route, bgp, error Duplicate remote Routerid: xx.xx.xx.xx < where xx.xx.xx.xx is our router ID/ loopback IP.
RemoteAddress= yy.yy.yy.yy < where yy.yy.yy.yy is the remote IP of the new bpg peer.

Router is running ROS 6.37.5 (originally we saw this error when run ROS.6.32.4, we upgraded, and still have the same error).

Any thoughts and suggestions ?

Here is the debug..

===============================
May/15/2017 10:43:26 route,bgp,debug RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug,state Entering Connect state
May/15/2017 10:43:26 route,bgp,debug,state RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,info TCP connection established
May/15/2017 10:43:26 route,bgp,info RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug,state Entering OpenSent state
May/15/2017 10:43:26 route,bgp,debug,state RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,info Connection opened by remote host
May/15/2017 10:43:26 route,bgp,info RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug New incoming bgp connection
May/15/2017 10:43:26 route,bgp,debug LocalAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug LocalPort=179
May/15/2017 10:43:26 route,bgp,debug RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug RemotePort=37658
May/15/2017 10:43:26 route,bgp,debug,packet,raw Sent OPEN message
May/15/2017 10:43:26 route,bgp,debug,packet,raw RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug,packet,raw Length=45
May/15/2017 10:43:26 route,bgp,debug,packet,raw FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
May/15/2017 10:43:26 route,bgp,debug,packet,raw 00 2D 01 04 F4 B6 00 B4 17 5C 0E FD 10 02 0E 02
May/15/2017 10:43:26 route,bgp,debug,packet,raw 00 41 04 00 00 F4 B6 01 04 00 01 00 01
May/15/2017 10:43:26 route,bgp,debug,packet Sent OPEN message
May/15/2017 10:43:26 route,bgp,debug,packet RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug,packet Length=45
May/15/2017 10:43:26 route,bgp,debug,packet,raw Sent OPEN message
May/15/2017 10:43:26 route,bgp,debug,packet,raw RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug,packet,raw Length=45
May/15/2017 10:43:26 route,bgp,debug,packet,raw FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
May/15/2017 10:43:26 route,bgp,debug,packet,raw 00 2D 01 04 F4 B6 00 B4 17 5C 0E FD 10 02 0E 02
May/15/2017 10:43:26 route,bgp,debug,packet,raw 00 41 04 00 00 F4 B6 01 04 00 01 00 01
May/15/2017 10:43:26 route,bgp,debug,packet Sent OPEN message
May/15/2017 10:43:26 route,bgp,debug,packet RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug,packet Length=45
May/15/2017 10:43:26 route,bgp,debug,packet OPEN Message
May/15/2017 10:43:26 route,bgp,debug,packet RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug,packet MessageLength=45
May/15/2017 10:43:26 route,bgp,debug,packet,raw Received OPEN packet
May/15/2017 10:43:26 route,bgp,debug,packet,raw RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug,packet,raw Length=45
May/15/2017 10:43:26 route,bgp,debug,packet,raw FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
May/15/2017 10:43:26 route,bgp,debug,packet,raw 00 2D 01 04 F4 B6 00 B4 17 5C 0E FD 10 02 0E 02
May/15/2017 10:43:26 route,bgp,debug,packet,raw 00 41 04 00 00 F4 B6 01 04 00 01 00 01
May/15/2017 10:43:26 route,bgp,error Duplicate remote RouterId: xx.xx.xx.xx
May/15/2017 10:43:26 route,bgp,error RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug,packet OPEN Message
May/15/2017 10:43:26 route,bgp,debug,packet RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug,packet MessageLength=45
May/15/2017 10:43:26 route,bgp,debug,packet,raw Received OPEN packet
May/15/2017 10:43:26 route,bgp,debug,packet,raw RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug,packet,raw Length=45
May/15/2017 10:43:26 route,bgp,debug,packet,raw FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
May/15/2017 10:43:26 route,bgp,debug,packet,raw 00 2D 01 04 F4 B6 00 B4 17 5C 0E FD 10 02 0E 02
May/15/2017 10:43:26 route,bgp,debug,packet,raw 00 41 04 00 00 F4 B6 01 04 00 01 00 01
May/15/2017 10:43:26 route,bgp,error Duplicate remote RouterId: xx.xx.xx.xx
May/15/2017 10:43:26 route,bgp,error RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug,packet,raw Sent NOTIFICATION message
May/15/2017 10:43:26 route,bgp,debug,packet,raw RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug,packet,raw Length=21
May/15/2017 10:43:26 route,bgp,debug,packet,raw OPEN error: bad router-id
May/15/2017 10:43:26 route,bgp,debug,packet,raw FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
May/15/2017 10:43:26 route,bgp,debug,packet,raw 00 15 03 02 03
May/15/2017 10:43:26 route,bgp,debug,packet Sent NOTIFICATION message
May/15/2017 10:43:26 route,bgp,debug,packet RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug,packet Length=21
May/15/2017 10:43:26 route,bgp,debug,packet,raw Sent NOTIFICATION message
May/15/2017 10:43:26 route,bgp,debug,packet,raw RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug,packet,raw Length=21
May/15/2017 10:43:26 route,bgp,debug,packet,raw OPEN error: bad router-id
May/15/2017 10:43:26 route,bgp,debug,packet,raw FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
May/15/2017 10:43:26 route,bgp,debug,packet,raw 00 15 03 02 03
May/15/2017 10:43:26 route,bgp,debug,packet Sent NOTIFICATION message
May/15/2017 10:43:26 route,bgp,debug,packet RemoteAddress=yy.yy.yy.yy
May/15/2017 10:43:26 route,bgp,debug,packet Length=21
May/15/2017 10:43:26 route,bgp,debug,packet KEEPALIVE Message

2

Is it possible you’ve used a RFC1918 IP as your loopback IP and just out of sheer luck and coincidence this peer used the same one?

A troubleshooting step would be just to change your router-id in the BGP instance. Sadly this will (should) reset the BGP sessions you have causing routes to flap once likely.

3

The router IP is a public IP so there is no IP duplication.

Your suggestion on trying a different router-ip is a valid one, let me see if we can try that and see what happens.

Will report back.

4

Tried to use a different IP for the Router-ID, the session is still complaining but now with the new Router-ID (duplicate-id).

:frowning:

5

Just to be triple sure:

routing bgp instance print

The router-id value shown is what you’d expect? You keep saying router IP. A RID actually doesn’t have to be an IP on the system and can in fact be set to whatever you want. By default this should be the highest IP in the system.

6

We use a public IP for the Router Loopback interface, and we use that same IP address as the Router-ID (in the bgp instance).

Yes, I did change the Router-ID in the bgp instance (default instance), and verified..
This particular peer, when I enable it, gives me the same error message, duplicate router-id… (it give the changed router-id, after the router-id change).

7

Any chance the remote router ID is in use in any other BGP session?

8

Not with that peer… I have also shutdown all of my bgp session on this Edge Router, and then just turn up this particular peer, and I still get the same duplicate router-id message.

9

I’d probably be doing a packet capture at this point and reviewing the peering conversation on each side. That will probably yield some insight.

10

Thank you all for your suggestions and comments… I feel incredibly stupid… after staring at it and doing the packet capture… I realized that I was using my-own IP address (as assigned by the Peering Exchange) for the other peers remote address.

:frowning:

11

At least you got to the bottom of it. We’ve all had our own face-palm moments in this business. :slight_smile:

12

Peering with yourself :wink:

13

Even it is 2023 it can happen…I did the same error and I feel the same way…