<![CDATA[(Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses]]>I have noticed that on at least Windows Server 2025, using the vates maintaned XCP-ng Windows Gust Tools (v9.1.146.0). XO (same in both 5 & 6) doesn't seem to collapse the IPv6 zeroes as expected. Leading to l00000ng addresses visually.

0ec56081-b186-44c9-90c1-ac98806d24cb-image.jpeg

]]>https://xcp-ng.org/forum/topic/12142/windows-guest-ipv6-address-doesn-t-collapse-zeroes-long-ipv6-addressesRSS for NodeMon, 10 Aug 2026 07:38:23 GMTTue, 05 May 2026 07:40:25 GMT60<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Mon, 01 Jun 2026 10:56:10 GMT]]>

@dinhngtu said:

I've taken a quick look, looks like it'll be solved as part of the Windows guest agent overhaul, so please look forward to that.

Thanks for the info. I will be looking forward to that, indeed.

]]>https://xcp-ng.org/forum/post/105856https://xcp-ng.org/forum/post/105856Mon, 01 Jun 2026 10:56:10 GMT<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Mon, 01 Jun 2026 09:42:09 GMT]]>I've taken a quick look, looks like it'll be solved as part of the Windows guest agent overhaul, so please look forward to that.

]]>https://xcp-ng.org/forum/post/105850https://xcp-ng.org/forum/post/105850Mon, 01 Jun 2026 09:42:09 GMT<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Mon, 25 May 2026 11:46:37 GMT]]>Still, something to fix 🙂

]]>https://xcp-ng.org/forum/post/105714https://xcp-ng.org/forum/post/105714Mon, 25 May 2026 11:46:37 GMT<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Mon, 25 May 2026 11:13:30 GMT]]>@poddingue

I have done some more testing.
Windows Server 2022 is also affected. 9.1.145-77

I also tried the latest WindowsPV drivers from Vates, on Windows Server 2025. 9.1.200-0. And the "problem" still persists.

It is a very low impact and low importance "problem". Since it is afaik purely costmetical.

]]>https://xcp-ng.org/forum/post/105713https://xcp-ng.org/forum/post/105713Mon, 25 May 2026 11:13:30 GMT<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Thu, 14 May 2026 10:58:20 GMT]]>Thanks for the ping and for narrowing it down; that live-migration repro is a really useful signal. 👍
I don't know enough about how the guest tools report IPs back through XAPI to say where the canonicalisation should happen, but it sounds like something @Team-Hypervisor-Kernel might want to look at since the trigger is on the agent side after migration. 🤷
If it turns out to be reproducible on another Windows guest version (2022, 2019), that might help narrow it further; no pressure though, you've already done the hard part. 🙏

]]>https://xcp-ng.org/forum/post/105405https://xcp-ng.org/forum/post/105405Thu, 14 May 2026 10:58:20 GMT<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Wed, 13 May 2026 08:58:12 GMT]]>ping @poddingue for visibility as I believe I've found the trigger for IPv6 expanding... Live Migrations

]]>https://xcp-ng.org/forum/post/105372https://xcp-ng.org/forum/post/105372Wed, 13 May 2026 08:58:12 GMT<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Wed, 06 May 2026 10:58:34 GMT]]>@TeddyAstie

I do not have Citrix ones. This VM was pretty much freshly installed to test Windows2025 on as pure Vates-maintained stack as possible.

Update: Please note my post above. Tha this seems to be triggered by live-migrating the vm

]]>https://xcp-ng.org/forum/post/105114https://xcp-ng.org/forum/post/105114Wed, 06 May 2026 10:58:34 GMT<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Wed, 06 May 2026 10:21:48 GMT]]>Do you have multiple guests agents in the VM (e.g Citrix and XCP-ng ones) that may step on each other for this IP ?

]]>https://xcp-ng.org/forum/post/105113https://xcp-ng.org/forum/post/105113Wed, 06 May 2026 10:21:48 GMT<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Wed, 06 May 2026 10:21:12 GMT]]>I believe I have a reproducible method to make it expand.
The trick aparently is Live migrating the VM.

After reboot

Pre live migration:
5f44f037-3b0a-4b26-927f-f4142399ea4d-image.jpeg

Post live migration:
52b4fcbf-d7bb-4810-b610-997dbf98530f-image.jpeg

]]>https://xcp-ng.org/forum/post/105112https://xcp-ng.org/forum/post/105112Wed, 06 May 2026 10:21:12 GMT<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Wed, 06 May 2026 10:17:17 GMT]]>I have now tried updating to the latest version included in the xcp-ng guest-tools.iso. Followed by a reboot.

At the moment, the zeroes are collapsed. But I won't count my chickens before they've hatched. So I will reply back if they expand out again (as seen before).

Thanks!

]]>https://xcp-ng.org/forum/post/105111https://xcp-ng.org/forum/post/105111Wed, 06 May 2026 10:17:17 GMT<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Wed, 06 May 2026 09:03:00 GMT]]>

@dinhngtu said:

@jr-m4 Could you check if your VMs are using XenServer or XCP-ng tools?

They are using the vates provided xcp-ng guest tools.
80a1bf8d-0557-4058-a094-c4f1d3611bc8-image.jpeg

]]>https://xcp-ng.org/forum/post/105108https://xcp-ng.org/forum/post/105108Wed, 06 May 2026 09:03:00 GMT<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Wed, 06 May 2026 08:59:00 GMT]]>@jr-m4 Could you check if your VMs are using XenServer or XCP-ng tools?

]]>https://xcp-ng.org/forum/post/105107https://xcp-ng.org/forum/post/105107Wed, 06 May 2026 08:59:00 GMT<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Wed, 06 May 2026 08:46:11 GMT]]>After applying latest updates and commits, to both xcp and XO. The zeroes were still non-collapsed.

However. Rebooting the VM resulted in the zeroes now collapse properly as expected.

I had previously rebooted the VM, so I don't believe that was the solution. But I did not check inbetween pulling latest source, and updating XCP. So I'm unsure which update solved it.

But this then has been resolved.
Update: Not solved! Now on fully updated XCP & XO, and the VM being rebooted as per post-details above.

]]>https://xcp-ng.org/forum/post/105099https://xcp-ng.org/forum/post/105099Wed, 06 May 2026 08:46:11 GMT<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Wed, 06 May 2026 04:56:13 GMT]]>

@olivierlambert said:

Well, I'm not seeing the same behavior here, fe80::4496:9d87:690d:ccc7 is collapsed, unlike in your screenshot 🤔

I'm now back with better information from the original pool.

xe vm-list uuid=0513005e-3626-1867-306d-9d5415cd6516 params=networks
networks (MRO)    : 0/ip: 192.168.97.60; 0/ipv4/0: 192.168.97.60; 0/ipv6/0: fe80:0000:0000:0000:a57c:c544:3b03:8910

I will apply latest updates to see if this has any bearing on the matter.

]]>https://xcp-ng.org/forum/post/105098https://xcp-ng.org/forum/post/105098Wed, 06 May 2026 04:56:13 GMT<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Tue, 05 May 2026 15:58:26 GMT]]>This seems to be specific to XenServer guest agents?

]]>https://xcp-ng.org/forum/post/105058https://xcp-ng.org/forum/post/105058Tue, 05 May 2026 15:58:26 GMT<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Tue, 05 May 2026 15:50:32 GMT]]>@olivierlambert

I will check back tomorrow when I'm back at that lab-pool. Sorry for taking your time thus far. I will provide more and better info tomorrow

]]>https://xcp-ng.org/forum/post/105057https://xcp-ng.org/forum/post/105057Tue, 05 May 2026 15:50:32 GMT<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Tue, 05 May 2026 14:41:06 GMT]]>Well, I'm not seeing the same behavior here, fe80::4496:9d87:690d:ccc7 is collapsed, unlike in your screenshot 🤔

]]>https://xcp-ng.org/forum/post/105051https://xcp-ng.org/forum/post/105051Tue, 05 May 2026 14:41:06 GMT<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Tue, 05 May 2026 16:35:32 GMT]]>

@olivierlambert said:

So is it a display issue from XO or a problem for the tools? (not sure to get it).

What's the output of xe CLI?

This is me (jr-m4) from another (private) account.

Update: Details below are incorrect information.

xe Output for another windows 2025 guest, where I'm seeing the same behaviour

[16:25 xcp ~]# xe vm-list uuid=3d3b8ba4-09c1-039d-8d58-ec797e7a05c3 params=networks
networks (MRO)    : 0/ip: 192.168.80.234; 0/ipv4/0: 192.168.80.234; 0/ipv6/0: fe80::4496:9d87:690d:ccc7
]]>https://xcp-ng.org/forum/post/105049https://xcp-ng.org/forum/post/105049Tue, 05 May 2026 16:35:32 GMT<![CDATA[Reply to (Windows) guest IPv6 address doesn't collapse zeroes -> Long IPv6 addresses on Tue, 05 May 2026 13:54:47 GMT]]>So is it a display issue from XO or a problem for the tools? (not sure to get it).

What's the output of xe CLI?

]]>https://xcp-ng.org/forum/post/105045https://xcp-ng.org/forum/post/105045Tue, 05 May 2026 13:54:47 GMT