Connection works, ping does not

[Hendrik Friedel]

Hello,

(I posted this a while ago, but it never appeared on the list; if the list is the wrong place for this question, please let me know; I would appreciate a hint for a more appropriate place)

I am using wireguard to connect two machines.
My local server is connected  to the internet via a router. I am using theis Server also for connecting other devices (e.g. mobile phones) to my home network. This works great.

But when connecting to another server (both debian 10), I only get a successful connection, but no ping.
*My server:*

wg show
interface: wgnet0
   public key: xxxxx=
   private key: (hidden)
   listening port: 51820

peer: sdfsdfsdfsdfsdfsdf=
   endpoint: 109.41.64.83:15167
   allowed ips: 10.192.122.2/32
   latest handshake: 1 minute, 7 seconds ago
   transfer: 10.95 MiB received, 40.35 MiB sent

peer: yyyy=
   endpoint: 185.22.142.254:51380
   allowed ips: 10.192.122.3/32
   transfer: 0 B received, 5.20 KiB sent

peer: yyyy=
   endpoint: 93.214.229.137:64119
   allowed ips: 10.192.122.4/32

peer: yyyy=
   endpoint: 93.214.225.116:49819
   allowed ips: 10.192.122.5/32

peer: yyyy=
   allowed ips: 10.192.122.6/32

peer: yyyy=
   allowed ips: 10.192.122.7/32


more /etc/wireguard/wgnet0.conf
[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 = aaa=

[Peer]
PublicKey = yyyy=
AllowedIPs = 10.192.122.2/32
Endpoint = 123.41.67.233:18314

[Peer]
PublicKey = xxx=
AllowedIPs = 10.192.122.3/32
Endpoint = 123.22.142.254:51380





ip route
default via 192.168.177.1 dev eth0 proto static
10.192.122.0/24 dev wgnet0 proto kernel scope link src 10.192.122.1

and the other side/server:

interface: wgnet0
   public key: xxxxx=
   private key: (hidden)
   listening port: 54004
   fwmark: 0xca6c

peer: yyyyy=
   endpoint: [2003:cb:aaa:bbb:9ec7:a6ff:fefd:3a6d]:51820
   allowed ips: 0.0.0.0/0
   transfer: 0 B received, 2.75 KiB sent
   persistent keepalive: every 25 seconds



   more wgnet0.conf
[Interface]
Address = 10.192.122.3/32
PrivateKey = xxxxx=

[Peer]
PublicKey = yyyyy=
Endpoint = v.myfritz.net:51820
AllowedIPs = 0.0.0.0/0
PersistentKeepalive = 25

It seems to me, that the connection is successfully established , but data is only transmitted in one direction.

How can I find the reason?

Regards,
Hendrik