OSX 15.1.1 and ipv6 cause route problem

[atoy40]

Hi,

It seems the last OSX update (15.1.1) cause a problem with the OpenVPN Connect client.

If the client is connected to an ipv4-only network, no problem, the client connect and setup his routes. But if the client is connected on an ipv4/ipv6 network, then the beahvior change :

first, even if the vpn remote is IPV4, the log show the use of a NAT64 address :

[Dec 3, 2024, 15:13:34] Connecting to [1.2.3.4]:1194 (64:ff9b::0102:0304) via UDP

Then an error occurs when the ovpn connect client add the route to the remote :

/sbin/route add -net -inet6 64:ff9b::0102:0304 -prefixlen 128 fe80:b::600f:6bff:fe01:ad64%en0%en0
fe80:b::600f:6bff:fe01:ad64%en0%en0: nodename nor servname provided, or not known

The problem seems to be the repetition of the target interface add the end of the nexthop (%en0%en0)

If the remote is an ipv6 address, same problem happens. for the user, the client seems connected, but there is a lot off "no route to host" message in the OpenVPN Connect log view.

The work arround we found is to disable ipv6 on the interface using the following command :

networksetup -setv6off Wi-Fi

thanks
Anthony.

[Admiral Ackbar]

Hello,

We are currently facing the exact same issue, the last update of the OpenVPN client didn't fix it unfortunately.
On a IPv4-only network, there is no problem. It only occurs on a IPv4/IPv6 network

As for OP, the only fix we could find until now is to block IPv6 in the advanced settings of the OVPN Connect client.

MacOS 15.2
OpenVPN Connect 3.6.0 (5410)

When looking at the logs, we still have the same error even though the user think he is connected.

/sbin/route add -net -inet6 xxxx:xxxx:c:10::5 -prefixlen 128 xxxx:e::xxxx:xxxx:xxxx:xxxx%en0%en0
xxxx:e::xxxx:xxxx:xxxx:xxx%en0%en0: nodename nor servname provided, or not known

UDP send exception: send: No route to host

We hoped the 3.6.0 version would fix the issue but still the same problem since MacOS 15.1.1 (the same happens for users on 14.7.1 also).

Is the issue acknowledged already by the OpenVPN team?

Thank you for your help!