I have a setup in which the Server IP is known, whereas the Client IP is changing. Thus, I rely on the Client to connect to the Server. I want the Client to keep the connection alive all the time though, so that the Server can also initiate a connection to the Server when needed. Both, client and server are behind a NAT/Router.

I would think, that the "PersistentKeepalive = 25" on the Client would ckeep the connection open. The connection works fine while used. But after a while, I cannot connect from the Server to the client anymore.

I would assume that a ping from the Client to the IP of the endpoint would help to re-alive the connection - but it does not.

Only after a wg-quick down and up all is fine again.

Below some more information.

Can you help me to find, what I am doing wrong?

Regards,

Hendrik

At the time of the problem "wg" shows on the Client:

interface: wgnet0
  public key: cebXSxxx=
  private key: (hidden)
  listening port: 60147
  fwmark: 0xca6c

peer:  oNjoixxx=
  endpoint: 92.210.7.177:51820
  allowed ips: 0.0.0.0/0
  latest handshake: 1 day, 7 hours, 44 minutes, 19 seconds ago
  transfer: 48.48 GiB received, 1.22 TiB sent
  persistent keepalive: every 25 seconds

and on the Server

 wg
interface: wgnet0
  public key: oNjoijXxxx=

  private key: (hidden)
  listening port: 51820

peer: cebXSxx=
  endpoint: 185.22.142.254:60147
  allowed ips: 10.192.122.3/32
  latest handshake: 1 day, 7 hours, 46 minutes, 5 seconds ago
  transfer: 67.24 MiB received, 651.37 MiB sent

peer: ZiTlYnxx=
  endpoint: 109.41.65.27:5935
  allowed ips: 10.192.122.2/32
  latest handshake: 2 days, 21 hours, 49 minutes, 25 seconds ago
  transfer: 11.98 MiB received, 127.11 MiB sent

Note the "transfer" being different between the two by far. I show the peer "ZiTIY" for completeness only. I do not think that it is relevant.

The Client config:

[Interface]

Address = 10.192.122.3/32

PrivateKey = xx=

[Peer]

PublicKey = yy=

Endpoint = Dyn.IP:51820

AllowedIPs = 0.0.0.0/0

PersistentKeepalive = 25

The Server config:

[Interface]

Address = 10.192.122.1/24

SaveConfig = true

PostUp = iptables -A FORWARD -i wgnet0 -j ACCEPT; iptables -A FORWARD -o wgnet0 -j ACCEPT; iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

PostDown = iptables -D FORWARD -i wgnet0 -j ACCEPT; iptables -D FORWARD -o wgnet0 -j ACCEPT; iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE

ListenPort = 51820

PrivateKey = aa=

[Peer]

PublicKey = bb=

AllowedIPs = 10.192.122.2/32

Endpoint = hidden:41646

[Peer]

PublicKey = cc=

AllowedIPs = 10.192.122.3/32

Endpoint = hidden:60147