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I have Cisco Nexus tor switch connected with multiple servers on 25G nic. When I am pinging from server1 to server2 I am seeing higher latency in ping. After tcpdump found server replying ping reply with tor switch gateway mac address. In short MAC getting changed which redirecting packet via VRF1.

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In tcpdump i found

ping 1.1.1.3 from 1.1.1.2 [ src: b:b:b:b dst: c:c:c:c ]

when server2 reply back it use [ src: c:c:c:c dst: a:a:a:a ]

Technically it should use server1 mac address in icmp reply because they are in local LAN. This is EVPN fabric leaf switch. I have native + tagged vlan configured on switch.

#EDIT

interface Vlan10 no shutdown mtu 9216 vrf member MGMT ip address 10.10.10.1/24 fabric forwarding mode anycast-gateway interface Vlan11 no shutdown mtu 9216 vrf member L3GW ip address 1.1.1.1/24 fabric forwarding mode anycast-gateway interface Ethernet1/1 description server1 switchport switchport mode trunk switchport trunk native vlan 10 spanning-tree port type edge trunk spanning-tree bpduguard enable mtu 9216 interface Ethernet1/2 description server2 switchport switchport mode trunk switchport trunk native vlan 10 spanning-tree port type edge trunk spanning-tree bpduguard enable mtu 9216

I have notice one thing on server2 in ip neigh output where entry is STALE. We have arp suppression enabled on cisco evpn fabric.

root@server2:~# ip neigh show | grep b:b:b:b 1.1.1.2 dev vlan11 lladdr b:b:b:b STALE 10.10.10.2 dev ens2f0 lladdr b:b:b:b REACHABLE
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  • We'll need to see the switch configuration (in text format, using the editor's {} preformat option). Commented Mar 21 at 19:53
  • I have edited my question with cisco switch config, look like server2 not able validate arp mac and may be its not able to communicate and that is why sending packet to gw. Commented Mar 21 at 20:58
  • Have you tried sending a gratuitous arp from server 1? Commented Mar 22 at 13:58
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    What is the arp table in server1? I see you use native vlan 10, and your server is on vlan 11 - do your servers add vlan 11 tag? Commented Mar 22 at 19:17
  • Yes, I do have vlan10 ip on physical nic eth0 and vlan11 on eth0.11 Commented Mar 24 at 16:31

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