need another clue: howto transparently bridge VLANs

RouterOS General
1

Background: goal is to insert MikroTik acting as a transparent bridge between Cisco and EtherSwitch. There are multiple (and increasing due to growth) VLANs in use on the pipe.

http://www.mikrotik.com/docs/ros/2.9/interface/vlan says in part:

And VLAN successfully passes through Ethernet bridges (for MikroTik RouterOS bridges you should set forward-protocols to ip, arp and other; for other bridges there should be analogical settings).

and http://www.mikrotik.com/docs/ros/2.9/interface/bridge says in part:

To add and enable a bridge interface that will forward all the protocols:

[admin@MikroTik] interface bridge> add; print
Flags: X - disabled, R - running
0 R name=“bridge1” mtu=1500 arp=enabled mac-address=61:64:64:72:65:73 stp=no
priority=32768 ageing-time=5m forward-delay=15s
garbage-collection-interval=4s hello-time=2s max-message-age=20s
[admin@MikroTik] interface bridge> enable 0

I’m not sure how to verify that the last sniplet accomplishes “set forward-protocols to ip, arp and other” and, if it does not, how to do so.

How do you achieve all packets (regardless VLAN id) passing through the [transparent] bridge?

The reason I ask is that the Cisco is claiming CRC erros when the MikroTik is inserted into the configuration and our Cisco guy thinks it is VLAN oriented.

thnx/ldv

2

You can verify what protocols are forwarded, by going to>
Interfaces/bridge1/bridge…
there you should see a check boxed for the protocols selected, we use IP, ARP and Other.

deselect IPv6, Apple-Talk and IPX.

This cofiguration will allow all packets through for the protocols selected to pass through the bridge.

Regards, Hugh

3

CRC errors are a physical level problem. It’s probably an ethernet duplex mismatch or something like that. Ciscos don’t always auto-negotiate ethernet settings well with other devices. In such a case, forcing an ethernet speed/duplex setting helps.