IPv6 VPN: Routing issue with macos client

[Nico Schottelius]

Hello,

when using IPv6 only VPNs on macos, IPv4 traffic outside of the local
network stops working. I am using the latest macos client as found in
the app store.

I have seen similar issues with the Android client
before, where DNS resolution will fail with IPv6 only VPNs, because the
regular IPv4 nameservers are not being used or reachable anymore - there
the "fix" was to add IPv6 nameservers to the wireguard configuration.

Is there any way to only send IPv6 traffic through wireguard with macos?

Best,

Nico


# Wireguard on:
--- 185.203.112.17 ping statistics ---
2 packets transmitted, 0 packets received, 100.0% packet loss
lily:.ctt verysanghee$ ping6 -c2 ungleich.ch
PING6(56=40+8+8 bytes) 2a0a:e5c1:113::42 --> 2a0a:e5c0::2:400:b3ff:fe39:795c
16 bytes from 2a0a:e5c0::2:400:b3ff:fe39:795c, icmp_seq=0 hlim=61 time=27.821 ms
16 bytes from 2a0a:e5c0::2:400:b3ff:fe39:795c, icmp_seq=1 hlim=61 time=34.119 ms

--- ungleich.ch ping6 statistics ---
2 packets transmitted, 2 packets received, 0.0% packet loss
round-trip min/avg/max/std-dev = 27.821/30.970/34.119/3.149 ms
lily:.ctt verysanghee$ ping -c2 ungleich.ch
PING ungleich.ch (185.203.112.17): 56 data bytes
ping: sendto: No route to host
ping: sendto: No route to host
Request timeout for icmp_seq 0

--- ungleich.ch ping statistics ---
2 packets transmitted, 0 packets received, 100.0% packet loss

lily:.ctt verysanghee$ traceroute -n 185.203.112.17
traceroute: findsaddr: write: No such process


# Wireguard off
lily:.ctt verysanghee$ ping6 -c2 ungleich.ch
ping6: UDP connect: No route to host
lily:.ctt verysanghee$ ping -c2 ungleich.ch
PING ungleich.ch (185.203.112.17): 56 data bytes
64 bytes from 185.203.112.17: icmp_seq=0 ttl=46 time=36.526 ms
64 bytes from 185.203.112.17: icmp_seq=1 ttl=46 time=25.020 ms

--- ungleich.ch ping statistics ---
2 packets transmitted, 2 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 25.020/30.773/36.526/5.753 ms
lily:.ctt verysanghee$



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