Showing which VLAN each MAC address is in on ports with several VLANs
9 posts
If you don't mind, I would like to suggest a new feature after dealing with the previous bug. On ports where there are multiple MAC addresses and multiple VLANs, you don't see which VLAN is applied to each MAC/IP combination; it would be a cool thing to add.
Best regards,
Matteo
Good idea, and it looks doable. The switch already records which VLAN each MAC address was learnt in, we just haven't been showing it.
Switches report this in different ways though, and on some it can't be used at all, so I'd like to look at real data first. Could you run SnmpWalk from OID 1 against a switch where you see this and send me the CSV export? One M4250 and one Zyxel would be ideal, as they are likely to do it differently.
Please also tell me the port, and a couple of the MAC addresses on it with the VLAN each one is in, so I can check the result against what you know.
Hello, I will be able to provide the snmpwalks next week since I am on vacation and don't have remote access to the Netgears.
Best regards,
Matteo
Hello, here are the two snmpwalks (zyxel with single vlan and netgear with multiple vlans).
Let me know if you need anything else.
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The Zyxel one came through fine, but the Netgear walk timed out in the RMON statistics, which are huge on that switch, before it got to the part I need. Could you run it once more on the M4250 with 1.3.6.1.2.1.17 as the starting OID instead of 1? That skips the statistics and should finish quickly.
Please also tell me which port you looked at and two or three MAC addresses on it with the VLAN each one is in.
Here is an updated snmpwalk for the Netgear. I had to limit the data between OID 1.3.6.1.2.1.17 and 1.3.6.1.2.1.32 to avoid timeouts, but it should contain all the required data for this case.
An example of a multivlan port without too much data to filter is port 23, with 00:1B:66:38:87:ED on vlan 139 and 00:1B:66:38:87:EF on vlan 250.
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Thanks, that was exactly what I needed. There is now a MAC VLAN column showing the VLAN each MAC address was learnt in. It is off by default, so turn it on under View → Columns → MAC VLAN and scan again. It's in the current version on the download page.
Let me know if it works on your switches.
Hello, I can confirm that it works as shown on all edge ports (where devices are connected), while on uplinks I see some duplication of MACs (which I guess talks to multiple VLANs; I see this on downstream switches or upstream switches and firewall MACs).
Best regards, Matteo
Those uplink MAC addresses really are learnt in several VLANs, but repeating the whole row for each one wasn't much use, so I've changed it. Each MAC address now has a single row, and the MAC VLAN column lists every VLAN it was learnt in, for example 11, 250. The VLAN name is shown only when there is just one.
It's in the current version on the download page.