Vlan Interfaces Disappearing

RouterOS General
1

Help!

We had at least two vlans disappear last night!

  • Nothing out of the ordinary shows up in the log or history.
  • I can’t add a new vlan interface with the same interface/vlan-id. I get the error message: “Couldn’t add New Interface - already have such vlan (6)”.
  • This happened once before but it was an unimportant vlan. When it happened before I did reboot the router but to no avail.
  • The IP on the router is still there. In winbox it’s interface shows “unknown”. It’s pingable from my machine.
  • Other IPs on that vlan are not accessible.
  • Version 6.11 (x86)

Any Ideas?

Thanks

2

Are you looking in Winbox or at the command line?

3

Winbox originally but it also doesn’t show up in the command line.

[rob@Boman Router] /interface vlan> :put [ /interface vlan get [ /interface vlan f
ind where vlan-id=120 ]]
no such item

It also dosn’t show up with just a /interface vlan print

4

I saw an odd behavior on VLANs on an earlier v6.xx at one point - I suggest that you update the ROS version and see if the problem disappears.

5

I’ll try that but It will have to wait until early morning. I’ve routed the vlans/subnets though an intermediate router for now.

6

Upgrade did the trick. Thanks~

7

I’ve had a situation with RouterOS v6.17 where almost all of my bridge interfaces were lost. A reboot of the device solved it, for now. It’s kind of strange though, as some of the traffic was still flowing through the device. So I wonder… whether it will happen again :wink:

8

Ugh, that’s scary…

9

Yes, the same situation at

RouterOS 6.34.6 na CCR1036-8G-2S+ FW:3.27

During making changes “ip route rules” all virtual interfaces simply disappear. No bridge, no vpls, no eoip. IP address assigned to this interface stay in the routing table with no assigned interface => but some traffic pass. Icmp echo to bridge interface pass. Newly created ip address is not listed in routing table. Reboot fix this state. Now is upgraded to 6.39.3 and 3.41. I will make some investigations about memory and look at capacitor health.

10

CPU stats from incident … one or two cpu cores goes up to 100%
https://ibb.co/n0vTWw