Can't imagine that the Aruba returns packets over another link in the trunk. Does everything work if you bring down one of the links and run on a single link?
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Herman Robers
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If you have urgent issues, always contact your Aruba partner, distributor, or Aruba TAC Support. Check
https://www.arubanetworks.com/support-services/contact-support/ for how to contact Aruba TAC. Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.
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Original Message:
Sent: Apr 12, 2024 03:08 AM
From: Timo Ruiter
Subject: IPv6 Neighbor Discovery over aggregated links
I have a Cisco switch connected to an Aruba switch with an aggregated link. The Cisco is configured as router and has a L3 ether-channel:
interface GigabitEthernet1/0/23
no switchport
channel-group 23 mode active
end
interface GigabitEthernet1/0/23
channel-group 23 mode active
end
interface Port-channel23
no switchport
ipv6 address FDDA:577C:1965:420::81/64
ipv6 enable
ipv6 ospf 81 area 1
end
trunk 1/1-1/2 trk1 lacp
interface 1/1
untagged vlan 420
trunk trk1 lacp
exit
interface 1/2
untagged vlan 420
trunk trk1 lacp
exit
My Cisco switch reports to receive IPv6 ND DAD packets for address fdda:577c:1965:420::81, as well as its auto configured address fe80::3e26:e4ff:fe14:a7ff that exists on the same interface. These packets can only have originated from itself, so apparently the packets sent out by the Cisco are somehow returned to it by the Aruba. (There is no way another device is sending out these packets, there is no duplicate address.)
My guess is that, since ND packets are flooded, the Aruba receives the packet on one physical interface of the aggregated link and floods it out of the other physical interface, so the Cisco has its own packet returned.
My other guess is that this is not how things should behave...
Is there anything missing or wrong with above configuration? Or is this a bug on the Aruba side?
Timo