0x00 Problem
I got this error message when I started wgcf.service.
6月 27 06:55:32 neon-push-3.localdomain wg-quick[2495]: [#] ip link add wgcf type wireguard
6月 27 06:55:32 neon-push-3.localdomain wg-quick[2495]: [#] wg setconf wgcf /dev/fd/63
6月 27 06:55:32 neon-push-3.localdomain wg-quick[2495]: [#] ip -4 address add 172.16.0.2/32 dev wgcf
6月 27 06:55:32 neon-push-3.localdomain wg-quick[2495]: [#] ip -6 address add fd01:5ca1:ab1e:82e0:e8e3:6864:b42e:5c5e/128 dev wgcf
6月 27 06:55:32 neon-push-3.localdomain wg-quick[2495]: [#] ip link set mtu 1280 up dev wgcf
6月 27 06:55:32 neon-push-3.localdomain wg-quick[2495]: [#] mount `8.8.8.8 2001:4860:4860::8888' /etc/resolv.conf
6月 27 06:55:32 neon-push-3.localdomain wg-quick[2495]: [#] wg set wgcf fwmark 51820
6月 27 06:55:32 neon-push-3.localdomain wg-quick[2495]: [#] ip -4 route add 0.0.0.0/0 dev wgcf table 51820
6月 27 06:55:32 neon-push-3.localdomain wg-quick[2495]: [#] ip -4 rule add not fwmark 51820 table 51820
6月 27 06:55:32 neon-push-3.localdomain wg-quick[2495]: [#] ip -4 rule add table main suppress_prefixlength 0
6月 27 06:55:32 neon-push-3.localdomain wg-quick[2495]: Error: argument "suppress_prefixlength" is wrong: Failed to parse rule type
6月 27 06:55:32 neon-push-3.localdomain wg-quick[2495]: [#] umount /etc/resolv.conf
6月 27 06:55:32 neon-push-3.localdomain wg-quick[2495]: [#] ip -4 rule delete table 51820
6月 27 06:55:32 neon-push-3.localdomain wg-quick[2495]: [#] ip link delete dev wgcf
6月 27 06:55:32 neon-push-3.localdomain systemd[1]: wg-quick@wgcf.service: main process exited, code=exited, status=255/n/a
6月 27 06:55:32 neon-push-3.localdomain systemd[1]: Failed to start WireGuard via wg-quick(8) for wgcf.
-- Subject: Unit wg-quick@wgcf.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit wg-quick@wgcf.service has failed.
--
-- The result is failed.
0x01 Solution
Another VPS's wgcf.service is normal, I am compared to their differences, guessing is the version of ip command.
So I updated its version:
[root@neon ~]# yum -y update iproute
Then it works.