Zoom Desktop Client with IPv6

[Cythrawl]

We have deployed Zoom Phone system with IP Phones etc at our offices along with Emergency addresses etc.
These all work just fine, and this is for people working remotely using the Desktop Client (on Windows).

Windows 11 has now started prioritizing IPv6 as the default protocol if it is available. So for example if you ping www.google.com in a command prompt it will respond with the IPv6 Address instead of the IPv4.

The problem with this is that the Zoom Client will complain that it cannot confirm my home address location and I will get the error at all times.

There are some workarounds.

1) Disable IPv6 on the router (not ideal)

2) Apply a registry fix to prioritize IPv4 over IPv6 on the OS (needs a reboot)

3) use command Prompt to manually set IPv4 Priority over IPv6 (Does not need a reboot but requires setting on subsequent reboots)

Once you have changed the priority and restart the desktop client the error goes away and it sets the Emergency Address correctly.

Is this behavior going to be addressed in a later version of the Desktop Client so it requires no user interaction?

Thanks

Shad

[Integris-JTran]

What's the Registry path/dwords for the #2 fix?

What's the command for the #3 fix?

Thanks in advance!

[Cythrawl]

Here is the Registry Settings to Prioritize TCPv4 over TCPv6

Spoiler

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters]
"DisabledComponents"=dword:00000020

Be aware this does NOT disable IPv6 you can still ping IPv6 clients, websites, etc but since Windows 11 now prioritizes IPv6 over IPv4 as default now, it gives issues with the location on the Zoom Desktop App and says it cannot get a location, this reverts it back to IPv4 as the priority.

to do this with command line, I will cut and paste the instructions here below..
I couldn't get it to stick after a reboot, so your mileage may vary.. 

Spoiler

This is slightly more complicated but you don't need to reboot your computer for the changes to take effect.

• Login to your computer.
• Open an elevated command prompt and type:

netsh interface ipv6 show prefixpolicies

You should see the following output:

Precedence  Label  Prefix
----------  -----  --------------------------------
        50      0  ::1/128
        40      1  ::/0
        35      4  ::ffff:0:0/96
        30      2  2002::/16
         5      5  2001::/32
         3     13  fc00::/7
         1     11  fec0::/10
         1     12  3ffe::/16
         1      3  ::/96

The first line with a precedence of 50 is the IPv6 localhost address. The second line with a precedence of 40 is all (global) IPv6 unicast addresses. The third with a precedence of 35 is all IPv4 to IPv6 mapped addresses. A complete list of IPv6 prefixes can be found here.

• To change the precedence you need to reorder the precedence of all prefix policies to ensure the IPv4 to IPv6 mapped addresses has the highest priority. All prefix policies must be entered. The higher the prefix value the more preferred it is. Hence, type or cut and paste the following at the elevated command prompt:

netsh interface ipv6 set prefixpolicy ::ffff:0:0/96 50 0
netsh interface ipv6 set prefixpolicy ::1/128 40 1
netsh interface ipv6 set prefixpolicy ::/0 30 2
netsh interface ipv6 set prefixpolicy 2002::/16 20 3
netsh interface ipv6 set prefixpolicy 2001::/32 5 5
netsh interface ipv6 set prefixpolicy fc00::/7 3 13
netsh interface ipv6 set prefixpolicy fec0::/10 1 11
netsh interface ipv6 set prefixpolicy 3ffe::/16 1 12
netsh interface ipv6 set prefixpolicy ::/96 1 4

• To confirm the changes have taken effect type the following:

netsh interface ipv6 show prefixpolicies

You will now see the precendence list has changed as follows:

Precedence  Label  Prefix
----------  -----  --------------------------------
        50      0  ::ffff:0:0/96
        40      1  ::1/128
        30      2  ::/0
        20      3  2002::/16
         5      5  2001::/32
         3     13  fc00::/7
         1     11  fec0::/10
         1     12  3ffe::/16
         1      4  ::/96

Now when you ping a host (for example), the IPv4 address (i.e. 127.0.0.1) will be used in preference to the IPv6 address (i.e. ::1). For example:

C:\>ping localhost

Pinging WORKSTATION [127.0.0.1] with 32 bytes of data:
Reply from 127.0.0.1: bytes=32 time<1ms TTL=128
Reply from 127.0.0.1: bytes=32 time<1ms TTL=128
Reply from 127.0.0.1: bytes=32 time<1ms TTL=128

To undo this change simply reset the precedence as follows:

netsh interface ipv6 reset

Hope this helps!

[sparrow]

Did you create a personal address for your remote/home location? You don't need to specify a IP subnet for your remote home location. The Zoom client automatically detects the public, private, and if using a wireless AP, it will save it once you create a personal address. If you did create a personal address? Are you getting an error?

[Integris-JTran]

No, we did not create a personal emergency address.

Our issue was nothing to do with the address (or so I think); it had to do with the IP versions that Zoom was propagating.

95% of our users are remote and some are switching locations daily. They use the softphone app and desktop client.

What led me to this particular forum post was that one of our Users said his softphone and headset worked fine.

On his laptop, sounds on all any application worked fine; until utilizing Zoom Phone via desktop client/workspace.

No voice/sound could be heard, incoming or outgoing... however, Meetings worked fine.

While comparing his settings to mine, the only difference we had was my Zoom Phone's Registered Server IP was an IPv4 and his was an IPv6. After disabling IPv6 on his laptop, everything worked perfectly fine for him.

I did re-enable IPv6 on his laptop (to avoid any interruptions to other apps and sites that he might access with IPv6) and we tested and the settings within Zoom phone kept the IPv4.
My concern is if he were to reboot or sometime down the line the registered server IP reverts back to IPv6; he will experience this same issue again.