Hi,

Just reporting this here because I can't make a support case for it (production equipment, and just wanted to get it up and running ASAP).

I have a BGP signaled MPLS network across a few sites with CCR routers. This morning I had a port flapping on one of the CCRs, so I decided to upgrade the firmware on the affected router from 6.20 through to 6.28 to rule that out as a cause.

When the router rebooted, my OSPF sessions were dropping every 10-30 seconds and resetting. After trying a large amount of things I figured out what it was.


After simplifying the network down to two CCRs, both with 6.28, I have a static IP on an interface facing each other. I then have OSPF running to advertise their loopback addresses. That works fine, and they can receive and ping each others loopback.

Then I enabled BGP onto of the OSPF sessions by using the loopback address of each for the peer address. Each peer was added with l2vpn as the address type in BGP, not ipv4.

This works fine and the connection establishes.

Then you go into the VPLS menu and create a BGP VPLS. As soon as you enable this setting you can see in the debug logs that the VPLS gets installed, then instantly the OSPF session will drop, meaning the loopback routes are removed, the BGP session will disconnect, and the VPLS will be removed.

The OSPF will then reconnect a few seconds later, and as soon as the BGP timer expires and restarts the BGP session, the BGP VPLS will connect, and the OSPF will die again.... Repeat x100000.


It seems the combo of BGP signaled VPLS on a OSPF base layer is stuffed in .28.

Exact same config and rolled back to 6.20 and it works perfectly (however my original port flapping problem may reappear now).

I hit this very same bug yesterday when bringing up a BGP-signalled VPLS on a CCR1036-8G-2S+ running 6.28 on an OSPF-routed backbone.

I was going to spend time today labbing up a simplified setup to rule out any more complex underlying cause with my network, but you've saved me the trouble by boiling it down to the basics, thanks!

Incidentally, it's worth noting that when I later successfully reproduced the same behaviour on a (much) less critical RB951G, I ran a CPU profile and found about 80% of CPU being used by the Routing process group.

Thanks for the post, always good to have someone else with the same problem!

I'm going to see if I can find some spare hardware and generate some logs for Mikrotik so we can get a confirmed fix in upcoming versions.

I'm going to see if I can find some spare hardware and generate some logs for Mikrotik so we can get a confirmed fix in upcoming versions.

Sounds good!

Did you end up filing a support request about this?
I'm happy to do so if you haven't, just don't want to create duplicate work for the support team.

I hit the same bug, and part of my network went down, 6.27 was fine but upgrading to 6.28 killed the network, looking at the change log it did not show anything on the ospf/bgp/mpls was changed. Thanks !

Hello,

Something similar happed to me with version 6.28 and 6.29RC22.

Here is a video: https://www.youtube.com/watch?v=ayO32xlww7U
Here are the configuration files: https://www.dropbox.com/sh/145kbzpw27ts ... hLQAa?dl=1

The problem with the tunnel happens only when you set to dynamically add it to the bridge.

In version 6.27 the BGP VPLS the tunnel works but if you reboot the router then it doesn’t come up automatically. I need to disable and then enable the BGP VPLS configuration in both sides.

Best regards.