MAC traceroute
Posted: Wed Aug 11, 2010 2:21 pm
by inertia
I need to do a MAC traceroute from RB1000. I want to see MAC address of every device that comes in between. Could i do it in winbox or any other software?
Re: MAC traceroute
Posted: Wed Aug 11, 2010 3:53 pm
by fewi
MAC addresses get replaced on layer 3 hops. There is no such thing as a MAC trace route on layer 2 networks.
Re: MAC traceroute
Posted: Thu Aug 12, 2010 8:27 pm
by Eising
IP traceroute in itself is a bit of a hack, because it exploits the fact that intermediate routers on a path will report an ICMP error if the TTL field is too low to go where the packet is destined. Switches, and other layer-2 devices do not have neither TTL nor any error reporting through ICMP which is why loops are dangerous on Layer 2.
If you need more hosts than traceroute can give you, you can sometimes use the record-route feature of standard ping. I'm not aware that this feature is available in RouterOS, but you can do it with a linux ping -R. It will, if it's supported and not blocked by intermediate hosts, tell you up to 9 ip-enabled hosts in your path. Some of them can be in your own broadcast domain, and is therefore the closest you will get to a "mac traceroute".