Mac address on routed ports belonging to separate VRFs are same

SN2100: MLNX-OS Rev 4.40 software version 3.6.1102

I’m following below steps

  1. create vrf1

  2. create 1st routed port Eth1/5 in vrf1

  3. create 2nd routed port Eth1/6 in default-vrf

  4. create 3rd routed port Eth1/7 in default-vrf

Observe mac address on all these interfaces are changed from their default values to a “router” mac address (which is set to system mac address 7c:fe:90:f8:e5:00 + 1)

The switch uses this “router” mac address as source mac instead of the per interface mac address on egress packets (say ping). why is this so ?

Specifically, can someone explain why

  1. mac addresses for multiple interfaces within VRF are same.

  2. mac addresses on interfaces across multiple VRFs are same.

One would expect to have a separate mac address at least per vrf level.

Thanks in advance for any help.

switch-2ce986 [standalone: master] # show run

vrf definition vrf1

ip routing vrf default

interface ethernet 1/5 no switchport force

interface ethernet 1/5 vrf forwarding vrf1

interface ethernet 1/6 no switchport force

interface ethernet 1/7 no switchport force

switch-2ce986 [standalone: master] # show interfaces ethernet 1/5

Eth1/5

Admin state: Enabled

Operational state: Down

Last change in operational status: Never

Description: N\A

Mac address: 7c:fe:90:f8:e5:01 <<<<<<<<<<<<<

MTU: 1500 bytes(Maximum packet size 1522 bytes)

Fec: auto

Flow-control: receive off send off

Actual speed: 40 Gbps

Width reduction mode: Not supported

DHCP client: Disabled

Arp timeout: 1500 seconds

VRF: vrf1 <<<<<<<<<<<<<

MAC learning mode: Enabled

Last clearing of “show interface” counters : Never

60 seconds ingress rate: 0 bits/sec, 0 bytes/sec, 0 packets/sec

60 seconds egress rate: 0 bits/sec, 0 bytes/sec, 0 packets/sec

switch-2ce986 [standalone: master] # show interfaces ethernet 1/6

Eth1/6

Admin state: Enabled

Operational state: Down

Last change in operational status: Never

Description: N\A

Mac address: 7c:fe:90:f8:e5:01 <<<<<<<<<<<<<<

MTU: 1500 bytes(Maximum packet size 1522 bytes)

Fec: auto

Flow-control: receive off send off

Actual speed: 40 Gbps

Width reduction mode: Not supported

DHCP client: Disabled

Arp timeout: 1500 seconds

VRF: default <<<<<<<<<<<<<<

MAC learning mode: Enabled

Last clearing of “show interface” counters : Never

60 seconds ingress rate: 0 bits/sec, 0 bytes/sec, 0 packets/sec

60 seconds egress rate: 0 bits/sec, 0 bytes/sec, 0 packets/sec

Eth1/7

Admin state: Enabled

Operational state: Down

Last change in operational status: Never

Description: N\A

Mac address: 7c:fe:90:f8:e5:01 <<<<<<<<<<<<<<

MTU: 1500 bytes(Maximum packet size 1522 bytes)

Fec: auto

Flow-control: receive off send off

Actual speed: 40 Gbps

Width reduction mode: Not supported

DHCP client: Disabled

Arp timeout: 1500 seconds

VRF: default <<<<<<<<<<<<<<

MAC learning mode: Enabled

Last clearing of “show interface” counters : Never

60 seconds ingress rate: 0 bits/sec, 0 bytes/sec, 0 packets/sec

60 seconds egress rate: 0 bits/sec, 0 bytes/sec, 0 packets/sec

With any way can we check arp table and mac address-table in vrf instances? is this possible? when I tried to see the mac address and details through switch 3560, I was unable to see other detail. also, check out Belkin n300 Router Support https://www.belkinroutersupportnumber.com/belkin-n300-router/ for Belkin issues.

Is this an incomplete configuration? I don’t see IP addresses on these interfaces. Is IP routing configured, and vrf route distinguisher. The interfaces shown are all down. Do the mac addresses displayed change once they are UP?