Subject: Re: [PATCH net-next v2 3/4] selftests/net: Add env for container based tests

From: Jakub Kicinski <[email-masked]>
Date: Tue, 3 Mar 2026 15:47:58 -0800

On Sun,  1 Mar 2026 21:33:14 -0800 David Wei wrote:
> +class NetDrvContEnv(NetDrvEpEnv):
> +    """
> +    Class for an environment with a netkit pair setup for forwarding traffic
> +    between the physical interface and a network namespace.
> +      NETIF           = "eth0"
> +      LOCAL_V6        = "2001:db8::1"
> +      REMOTE_V6       = "2001:db8::2"
> +      LOCAL_PREFIX_V6 = "fd00:cafe::"

Since you have to respin for the Makefile issue - could you rewrite this
to use 2001:db8 for all addresses? ULA is a funny and odd thing.

LOCAL_V6        = "2001:db8:1::1"
REMOTE_V6       = "2001:db8:1::2"
LOCAL_PREFIX_V6 = "2001:db8:2::0/64"

?
> +        try:
> +            net = ipaddress.IPv6Network(local_prefix, strict=False)
> +        except ValueError:
> +            net = ipaddress.IPv6Network(f"{local_prefix}::/64", strict=False)

dunno if the fallback is really necessary, not including the prefix
length is a bit of a bug IMO.