On Wed, Sep 25, 2019 at 11:06:18AM +1000, Brassy Panache wrote:
> I have a kernel without IPv6 support.  I've noticed when running:
>
> $ wg-quick down vpn
>
>
> I receive the following errors:
>
> [#] ip -4 rule delete table 51820
> [#] ip -4 rule delete table main suppress_prefixlength 0
> RTNETLINK answers: Address family not supported by protocol
> Dump terminated
> RTNETLINK answers: Address family not supported by protocol
> Dump terminated
> [#] ip link delete dev vpn
> [#] resolvconf -d vpn -f
>
>
> This is caused by the assumption that the command:
>
> $ ip -6 rule show
>
>
> will run on the system.  I have made a change to my local wg-quick script
> which first tests if the command runs successfully before it clears the
> rules.  The same should probably also be done prior to running the IPv4
> version of the command.

Would this work?

diff --git a/src/tools/wg-quick/linux.bash b/src/tools/wg-quick/linux.bash
index e690944d..612ecd77 100755
--- a/src/tools/wg-quick/linux.bash
+++ b/src/tools/wg-quick/linux.bash
@@ -102,10 +102,10 @@ del_if() {
                while [[ $(ip -4 rule show) == *"from all lookup main suppress_prefixlength 0"* ]]; do
                        cmd ip -4 rule delete table main suppress_prefixlength 0
                done
-               while [[ $(ip -6 rule show) == *"lookup $table"* ]]; do
+               while [[ $(ip -6 rule show 2>/dev/null) == *"lookup $table"* ]]; do
                        cmd ip -6 rule delete table $table
                done
-               while [[ $(ip -6 rule show) == *"from all lookup main suppress_prefixlength 0"* ]]; do
+               while [[ $(ip -6 rule show 2>/dev/null) == *"from all lookup main suppress_prefixlength 0"* ]]; do
                        cmd ip -6 rule delete table main suppress_prefixlength 0
                done
        fi