Posted on March 10, 2021 2:24 am
 |  Asked by Udo Lapuschkin
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I am using several vEOS systems on a KVM host in the lab.
As soon as an interface is configured with “no switchport” the MAC address changes.
From this moment on the macvTab interface is not reachable from outside, because the KVM host does not know this new mac address.
Therefore I want to use the mac-address command on this interface.
Although there is no error message this command does not work?

leaf21#show ver
Hardware version:
Serial number:
System MAC address: 5254.0060.af93

Software image version: 4.23.2F
Architecture: i686
Internal build version: 4.23.2F-15405360.4232F
Internal build ID: 4cde5c53-3642-4934-8bcc-05691ffd79b3

Uptime: 0 weeks, 0 days, 18 hours and 44 minutes
Total memory: 8121744 kB
Free memory: 7202384 kB

leaf21#conf t
leaf21(config)#int eth8
leaf21(config-if-Et8)#mac-address 00aa.00bb.00cc
leaf21(config-if-Et8)#show int eth8
Ethernet8 is up, line protocol is up (connected)
Hardware is Ethernet, address is 5254.0060.af93
Description: mgmt
Internet address is
Broadcast address is
IP MTU 1500 bytes (default)

Posted by Brad Brad
Answered on March 11, 2021 6:19 pm

Same problem with 4.25.2F in ESXi on NSX-T segments between routers. With a custom mac learning policy I can loosen the restrictions to make them connect, but then each veos-lab instance starts using 4Ghz of CPU while doing nothing. This could be DPDK mode, but unlike the cloud .ova there's no /mnt/flash/veos-config to go look at or disable it, so... painful.

Posted by Tamas Plugor
Answered on March 11, 2021 9:24 pm

@Udo using the mac address command in vEOS-lab is not supported today (it's a hardware-only feature), will file a bug to throw an error, without the macvtap driver this works fine, I can do a bit more digging if it can be made to work with macvtap, can you tell me the use case in the meantime please?

@Brad you can create the veos-config file in flash in vEOS-lab and change the MAC and SN,etc, it's been like that from the beginning. The file doesn't exist by default on vEOS-lab; on cloudEOS it does as there we also set the DPDK mode (sfe) by default, so it shouldn't be a problem on vEOS-lab either. You can also guestmount the disk and create the veos-config file before booting it

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