ARP not working for one VLAN in trunk

johnwcalder — Thu, 12 Sep 2024 10:58:21 GMT

I have a X460G2-24x-10G4 connected to a customer's Cisco Catalyst C8200 on port 23 with VLANs 12 and 21 tagged there.
I can see the MAC address from the Catalyst on VLAN 12 but not VLAN 21
The tagging of the VLANs is identical in the Extreme switch and from what I can tell it is identical in the C8200

EXOS config
show fdb port 23
MAC VLAN Name( Tag) Age Flags Port / Virtual Port List
------------------------------------------------------------------------------------------------------
e4:4e:2d:4d:47:f1 VLAN12(0012) 0000 dhm 23

show port 23 vlan
Untagged
Port /Tagged VLAN Name(s)
-------- -------- ------------------------------------------------------------
23 Untagged None
Tagged VLAN12, VLAN21

Catalyst config
show running-config int gigabitEthernet 0/0/1.12
Building configuration…

Current configuration : 287 bytes
!
interface GigabitEthernet0/0/1.12
description Biz-Internet TLOC
encapsulation dot1Q 12
ip address 172.30.202.90 255.255.255.252
no ip redirects
ip mtu 1500
ip nat outside
endpoint-tracker dia-biz-inet
arp timeout 1200
service-policy output shape_GigabitEthernet0/0/1.12
end

show running-config int gigabitEthernet 0/0/1.21
Building configuration…

Current configuration : 155 bytes
!
interface GigabitEthernet0/0/1.21
encapsulation dot1q 21
ip address 172.30.203.89 255.255.255.252
no ip redirects
ip mtu 1500
ip nat outside
endpoint-tracker dia-pub-inet
arp timeout 1200
service-policy output shape_GigabitEthernet0/0/1.21
end

The configuration in the Extreme switch is identical to another switch I have in a different datacenter that is also connected to a Catalyst, however both VLANs see the MAC from the catalyst there.

Re: ARP not working for one VLAN in trunk

Chris_H — Thu, 12 Sep 2024 12:55:10 GMT

I can't comment on the Catalyst side, but can you paste the output of "show vlan21"?

Also you're sure that there was traffic flowing that made the switch learn an FDB entry on VLAN21?

topic ARP not working for one VLAN in trunk in ExtremeSwitching (EXOS/Switch Engine)

ARP not working for one VLAN in trunk

Re: ARP not working for one VLAN in trunk