Cannot pass IPv6 packets using HP 5830s

[GRC-DL-NSC-SA]

I'm in the process of enabling IPv6 in our domain. At this point I'm working with a very small subset of servers and devices. I'm only working with a single VLAN, too. It's more of a proof-of-concept than a full-scale deployment.

Right now im working with a firewall, two 5830s, two DCs (Windows, virtual), one physical server (Windows), and one web server (Windows, virtual). Everything is configured for IPv6 at this point. The problem? I cannot get the 5830s to pass IPv6 packets. No combination of pings work from any devices to another. Instead, i just get "Destination Host Unreachable"

If i try to ping from the firewall to any device, nothing. If i try to ping from the switches to any device, nothing. If i try to ping from server to any device, nothing. The oddest part? If i try to ping via fe80 addresses, that works.

At this point i've narrowed down the problem to the switches. afaik, they are configured correctly. I have given them unique IPv6 addresses. I've enabled IPv6; I've enabled IPv6 for the VLAN in question. I have specified a default route. Lord knows what else i've tried. im sure im forgetting stuff at this point.

We were running a very old firmware on them. just last week we updated the latest, and it's still a no-go.

We run a pretty simple domain. We dont have a myriad of different protocols. the switches act as top-of-rack pass-throughs with a few VLANs. That's it. We're not running IRF, or BGP, or OSMP or any of thsoe.

To prove that im not losing my mind, i took a separate HP switch, outside of this domain and gave it a random IPv6 address. I assigned an IPv6 address to a server connected to that switch. That's the only 2 things i did and they ping each other just fine. So what's wrong w/ these 5830s?

If anyone needs images or screenshots, let me know. I'm totally and completely stuck at this point. Thanks!

[GRC-DL-NSC-SA · Accepted solution]

For anyone encountering the same issue, we did figure it out eventually.

I compared our switch config to another, identical switch that had not been modified. It is part of a separate domain. They were nearly identical, except for a single line. At some point I had enabled Neighbor Discovery on the switches. This is disabled by default when IPv6 is enabled. As soon as I disabled ND, via the CLI, the switches started to pass IPv6 packets.

Quite the odd one - I would never have thought that ND would completely render IPv6 useless on these switches.

[Apachez-]

Sounds like you might have something else broken because ND is part of IPv6.

ND is the IPv6 edition of ARP:

https://en.wikipedia.org/wiki/Neighbor_Discovery_Protocol

[GRC-DL-NSC-SA]

Yeah, i know ND is part of IPv6, which is why i enabled it in the 1st place. On these switches, by default, ND is disabled. As soon as I disabled it again, things started working. I have no idea why.

[16again]

What's the exact command you entered to fix this?
Pinging LinkLocal fe80 addresses worked right away, seems to me like ND is also required for those addresses

[GRC-DL-NSC-SA]

by default, ND is disabled when IPv6 is enabled. I thought, at the time, that ND would be good and necessary, so i enabled it w/ some command like "neighbor discovery enable". When i disabled it again, i typed something like "undo neighbor discovery enable."

sorry, i dont remember right off w/o going back to a manual to find it.