1 Reply Latest reply on Oct 24, 2017 8:12 AM by cmm

    Mac address on routed ports belonging to separate VRFs are same

    atiyyagura

      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

      3. 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