Cisco 3550 to MT connection stalling

My ISP is supplying a subnet to their Cisco 3550. I’m bridging this subnet across a parking lot to my facility. The connection “dies” at different intervals. The point of failure is between the NIC on the MT and the Ethernet port on the Cisco.

Coming in from a workstation on the remote with winbox, I can see that the radios are up and the connection speeds are fine. I can ping the MT connected to the Cisco and also admin it.

If I disable and then re-enable the ether1 interface, the connection is restored and runs nicely for a while before stalling.

The support engineer at my ISP says that he does not see the MACs of the MT devices in the ARP table on the 3550. He does see the traffic that is moving when it is working, but not the MACs.

I’ve set the interface to 10Mbps, full duplex with auto-negotiate turned OFF. This matches the settings on the Cisco.

The actual bridge configuration is using WDS with MAC-to-MAC connectivity.

(Yes, I have checked and changed out the network cables. Yes, both devices are on a UPS. No lightning storms lately. No, if it was my choice, I would not use Cisco.)

Any help is sincerely appreciated.

Bill

What kind of device is used as MikroTik router ?
Is it RouterBOARD or x86 box ?
Try to put cheap switch between Cisco and NIC on MikroTik router, try with default settings for ‘interface ethernet’ as well it would be good to check with another NIC too.