Posted on May 1, 2020 7:14 pm
 |  Asked by Martin Wolf
 |  150 views
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Hello,

I was wondering what is defined as the Router port in the MAC address table.

When I do a show mac address-table:switch$sh mac address-table
Mac Address Table
——————————————————————

Vlan Mac Address Type Ports Moves Last Move
—- ———– —- —– —– ———
:
1001 002a.6512.7700 STATIC Router

 

I was wondering how the does learn these Router Port Mac entries and where do they originating from.

 

Thanks.

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Answered on May 1, 2020 8:08 pm

This is most likely the MAC address of the switch itself. Do you have an SVI  configured on this device (perhaps even VARP - virtual-router)?

The following commands should help you checking:

show version (shows various details regarding the device including the system mac address)show interfaces status (shows the interfaces on the device)
show ip virtual-router (shows the details regarding VARP configuration including vIP/vMAC)
show interfaces vlan [vlan-name] (shows the details regarding the SVI for the particular VLAN)

Hello Diogo, Thank you for your advice. When I ran 'show ip virtual-router': lh-7280yc-01a-80v#sh ip virtual-router IP virtual router is configured with MAC address: 001c.7300.0034 IP router is not configured with Mlag peer MAC address MAC address advertisement interval: 30 seconds No interface with virtual IP address Is there any way to suppress the population of the virtual router's MAC address?
(Martin Wolf at May 5, 2020 3:12 pm)
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Posted by Aniket Bhowmick
Answered on May 5, 2020 6:45 pm

Hi Martin,

The mac address- " 002a.6512.7700" (actually- 001a.6512.7700) belongs to some Seluxit NIC (based on MAC OUI lookup- https://www.wireshark.org/tools/oui-lookup.html).There is no MAC OUI based on 002a.65. But 001a.65 belongs to Seluxit NICs. So it might be possible that Seluxit is using this mac (002a.65) for some special service which required to modify the bit. Are you aware of any such service on Seluxit or any other vendor device where this mac might be configured?

The port "Router" mapped to a mac address means, any packet received on the switch, that has DMAC as the mac address mapped to "Router", will get routed. So the mac is used to take decision whether the packet should be routed or not.

But this is odd, as the mac mapped to port "Router" is not Arista but some other vendor. So if Arista switch receives any packet with DMAC=002a.6512.7700 (Seluxit NIC mac), the Arista switch will route it. This doesn't seem right.

Can you share the "show running-config" output from the switch? If you can attach a "show tech-support" file as well, it will be good.

Thanks,

Aniket

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