RouterOS becomes unreachable

RouterOS Beginner Basics
1

I have a CRS312 which I have set up as a switch connected to a pfSense LAN interface. ROS obtains an IP address via DHCP and is initially reachable, but after some period of time becomes unreachable. By unreachable, I mean that the ROS web UI is unavailable nor does it respond to ARP queries. pfSense continues to show a valid DHCP lease. I have not done any significant configuration changes (I updated ROS, changed password, etc.)

In addition, if I insert another unmanaged layer 2 switch in between pfSense and ROS, I can get the web UI again. Also, ROS functions as a switch the entire time.

Is this a simple configuration problem I can fix? Does anyone have any troubleshooting suggestions? (I will try WinBox next time I observe the problem, as I understand it can operate entirely on layer 2).

2

continues to show a valid DHCP lease

This does not indicate that the CRS still has the IP assigned on its interface… What i would do is connect directly to the CRS either through MAC or Serial port and check Logs, DHCP client status etc…

3

Have you checked the lease time of the PFsense DHCP config? Could be the Mikrotik is receiving a different IP after the said period of time. Also check for loops in your connection.

4

Thanks for the feedback. I was able to fix this by changing my bridge “Protocol Mode” to RSTP.

5

That implies that you’ve got an Ethernet loop somewhere, since that’s the only problem [R]STP solves.

I recommend you go find that loop and put RSTP out of a job for now.

Leave RSTP running so it can save you the next time it happens, though. This is very much a “don’t shoot the messenger” sort of thing.

6

Something else is wrong in your Network, why RSTP was disabled ?
Have you checked all the logs for Loops ?