I’ve used wireguard for a pretty long time on my server and the phone as a client. I’ve had the same configuration for at least 4-5 years and never had issues. Last week I moved to using pihole in a container with a macvlan interface, so it has a different IP address than my physical server. Then I went and changed the DNS server IP on the wireguard config on the phone. When I reconnected I see I can’t connect to any local IP address like I used to and I can’t figure out why.
The local LAN is 10.11.12.0/24, the VPN is on 10.11.13.0/24.
Here’s the server wireguard config:
[Interface]
Address = 10.11.13.1
ListenPort = 11194
PrivateKey = ...
PostUp = iptables -A FORWARD -i %i -j ACCEPT; iptables -A FORWARD -o %i -j ACCEPT; iptables -t nat -A POSTROUTING -o enp3s0 -j MASQUERADE
PostDown = iptables -D FORWARD -i %i -j ACCEPT; iptables -D FORWARD -o %i -j ACCEPT; iptables -t nat -D POSTROUTING -o enp3s0 -j MASQUERADE
[Peer]
# Galaxy S20+
PublicKey = U59JZqVbk2eFxTb7tteyu0WHlMTZsk68E7CF7v2AX2U=
AllowedIPs = 10.11.13.5/32
[Peer]
# narwhal - T480 job
PublicKey = Ja9OL13IoZA17GJq0/LbwizB9s2dRQLHHgW2C4TcFyY=
AllowedIPs = 10.11.13.7/32
And here’s the phone’s wireguard config:
Address = 10.11.13.5/24
DNS = 10.11.12.55
PrivateKey = ....
[Peer]
AllowedIPs = 10.11.0.0/16
Endpoint = my_dyndns_hostname:11194
PublicKey = 6aF1cJhH9oeQWr9LYOpH3wk+lN4k9/tSiAqV6LkUQ1Y=
I am able to connect and can ping 10.11.12.77, the IP address of the server, but nothing else. I have two RPis running as mpd servers and I used to be able to connect to them too, but not anymore. Their IP addresses are 10.11.12.105 and .106.
Also, before the dns change I was able (of course!) to use the local DNS I set up on the pihole, but now I’m not able to connect to the new DNS (.55) so I can’t get any local address to resolve.
I’m looking for some hints on what I’m doing wrong. Please help.
Try changing your NAT rule to
“iptables -t nat -A POSTROUTING -s 10.11.13.0/24 -o eth1 -j MASQUERADE”
Also try changing your AllowedIPs to 10.11.13.0/24
The other issue may be the ability of the host/server to reach the IP address of the pihole macvlan interface. Have a look at this page, it’s helped me out before -> https://adventurenotvacation.com/2020/12/01/docker-macvlan-and-debian/
You only need the masquerade rule.
iptables -t nat -A POSTROUTING -s 10.11.13.0/24 -o enp3s0 -j MASQUERADE
didn’t help, unfortunatelly.
Did you enable forwarding via sysctl?
sysctl net.ipv4.ip_forward
This should report
1
Yes. That was one of the first checks I did.
Coming back to this: it was a case of “did you turn it off and then back on?” I did some server upgrades a day before setting up wireguard and it’s possible there were some changes that needed a reboot. I just rebooted today and everything works as expected.