Posted on March 26, 2020 2:31 am
 |  Asked by Mencken Davidson
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Hello.   I’m trying to model some of our production devices using a cEOS lab, and seem to have *just* about everything working correctly (mlag, vxlan, etc…) *but* I can’t seem to get routed .1q subinterfaces to operate correctly.  The CLI configuration is accepted, and the interface status is “up”, but it shows an all-zeroes for the mac-address (which I read as a sign that something’s not right.)   Results are consistent with docker-assigned MAC address and with Arista-OUI MACs taken from a prod switch (written to /mnt/flash/system_mac_address)

I vaguely recall .1q not being supported on earlier VEOS and CEOS versions, but on the 4.23.2.F CEOS image, VLAN operations seems fine, and the dot1q sub-interface configuration seemed to be accepted, so maybe I got my hopes up prematurely?


020540#sh run interf eth12
interface Ethernet12
no switchport
ip address
020540#sh run interf eth12.100
interface Ethernet12.100
encapsulation dot1q vlan 100
ip address

020540#sh interf eth12
Ethernet12 is up, line protocol is up (connected)
Hardware is Ethernet, address is 444c.a8bf.1e99
Internet address is
Broadcast address is
IP MTU 1500 bytes
Full-duplex, Unconfigured, auto negotiation: off, uni-link: n/a
Up 30 seconds
Loopback Mode : None
2 link status changes since last clear
Last clearing of “show interface” counters never
5 minutes input rate 0 bps (- with framing overhead), 0 packets/sec
5 minutes output rate 0 bps (- with framing overhead), 0 packets/sec
0 packets input, 0 bytes
Received 0 broadcasts, 0 multicast
0 runts, 0 giants
0 input errors, 0 CRC, 0 alignment, 0 symbol, 0 input discards
0 PAUSE input
0 packets output, 0 bytes
Sent 0 broadcasts, 0 multicast
0 output errors, 0 collisions
0 late collision, 0 deferred, 0 output discards
0 PAUSE output
020540#sh interf eth12.100
Ethernet12.100 is up, line protocol is up (connected)
Hardware is Subinterface, address is 0000.0000.0000
IP MTU 1500 bytes (default)
Up 5 minutes, 41 seconds

020540#sh ip route connected | inc Ethernet12
C is directly connected, Ethernet12


Any assistance greatly appreciated!

Posted by Wei Su
Answered on April 1, 2020 7:11 pm

I have the same issue running 4.23.2F. Only difference is the other end is in a vrf. Wondering if I missed something?

Posted by Sreelekha
Answered on April 15, 2020 3:09 am

Hi Mencken and Wei,

The cEOS releases till 4.23.2F do not support sub-interfaces. More details are present in this discussion



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