Community discussions

MikroTik App
 
User avatar
Caci99
Forum Guru
Forum Guru
Topic Author
Posts: 1075
Joined: Wed Feb 21, 2007 2:26 pm
Location: Tirane
Contact:

Mac address of device attached to the CRS

Sat Jul 05, 2014 10:30 am

Is there any chance to know the mac address of computers connected to the ethernet interfaces of CRS-s, even better the IP address :)?
 
User avatar
rextended
Forum Guru
Forum Guru
Posts: 11982
Joined: Tue Feb 25, 2014 12:49 pm
Location: Italy
Contact:

Re: Mac address of device attached to the CRS

Sat Jul 05, 2014 10:43 am

Is there any chance to know the mac address of computers connected to the ethernet interfaces of CRS-s, even better the IP address :)?
sniff traffic... ;)
 
User avatar
Caci99
Forum Guru
Forum Guru
Topic Author
Posts: 1075
Joined: Wed Feb 21, 2007 2:26 pm
Location: Tirane
Contact:

Re: Mac address of device attached to the CRS

Sat Jul 05, 2014 10:52 am

Well, I have configured it as a switch, all interfaces are slaves to ether1, and I have disabled connection tracking on firewall. So it is not possible to sniff traffic.
I was hoping that the switch would learn and know the mac addresses of the devices attached to it, as a matter of fact it must do it since it is considered a Layer3 switch. But where to find this info?
 
User avatar
docmarius
Forum Guru
Forum Guru
Posts: 1222
Joined: Sat Nov 06, 2010 12:04 pm
Location: Timisoara, Romania
Contact:

Re: Mac address of device attached to the CRS

Sat Jul 05, 2014 1:27 pm

Create a bridge and put the port in question on it.
It will allow you to see the MACs under bridge/hosts.

I use a permanent bridge on the master port. Fast path will minimize the impact of the bridge on the system performance (it will do Gb traffic on that port without any issues).
And just get the port out of the switch and move it temporary to the bridge.
Take care not to lock yourself out of the device if it is in a remote location :-)
 
User avatar
Caci99
Forum Guru
Forum Guru
Topic Author
Posts: 1075
Joined: Wed Feb 21, 2007 2:26 pm
Location: Tirane
Contact:

Re: Mac address of device attached to the CRS

Sat Jul 05, 2014 3:44 pm

Create a bridge and put the port in question on it.
It will allow you to see the MACs under bridge/hosts.
Kind of a workaround, but shouldn't the switch learn the mac addresses of the devices attached to it? This information got to be somewhere on it :). MikroTik could kindly make it available.
 
User avatar
docmarius
Forum Guru
Forum Guru
Posts: 1222
Joined: Sat Nov 06, 2010 12:04 pm
Location: Timisoara, Romania
Contact:

Re: Mac address of device attached to the CRS

Sat Jul 05, 2014 7:33 pm

The information is "in" it, the problem is, can it be read from the switch chip, and if yes, what amount of resources would it require...
 
User avatar
Caci99
Forum Guru
Forum Guru
Topic Author
Posts: 1075
Joined: Wed Feb 21, 2007 2:26 pm
Location: Tirane
Contact:

Re: Mac address of device attached to the CRS

Sat Jul 05, 2014 8:33 pm

The information is "in" it, the problem is, can it be read from the switch chip, and if yes, what amount of resources would it require...
I don't think that collecting 24 mac addresses is that much resource hungry. If the switch can survive a bridge interface, which is a "software" interface, and gather information from it, then ...
 
User avatar
docmarius
Forum Guru
Forum Guru
Posts: 1222
Joined: Sat Nov 06, 2010 12:04 pm
Location: Timisoara, Romania
Contact:

Re: Mac address of device attached to the CRS

Sat Jul 05, 2014 9:42 pm

I'm not thinking about the router, but about the switch chip. Reading the switching table (again, if possible, we don't know that) could disrupt normal switching.
Then again, this would make a nice feature request for the CRS series.
 
rwaters
just joined
Posts: 19
Joined: Sat Jan 28, 2012 5:56 pm
Location: USA

Re: Mac address of device attached to the CRS

Mon Jul 07, 2014 1:00 am

It should "learn" MAC addresses and store it in the switch chips forwarding database (FDB). In winbox I can goto the switch menu, FDBs and see all the learned MAC and what port learned from in the Unicast FDB tab
You do not have the required permissions to view the files attached to this post.
 
User avatar
Caci99
Forum Guru
Forum Guru
Topic Author
Posts: 1075
Joined: Wed Feb 21, 2007 2:26 pm
Location: Tirane
Contact:

Re: Mac address of device attached to the CRS

Mon Jul 07, 2014 12:05 pm

@rwaters
Nice spotting, that was it :)

Who is online

Users browsing this forum: No registered users and 28 guests