Can't ping other clients when connected to vpn server

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apache8080
OpenVpn Newbie
Posts: 16
Joined: Fri May 22, 2020 12:51 am

Can't ping other clients when connected to vpn server

Post by apache8080 » Thu Jul 23, 2020 10:50 pm

I have clients successfully connecting to my oepnvpn server and I can ping the clients from the server but when I try to ping clients from other clients it times out. Any ideas on how to fix this?

I have the following client config. This is the config at the top of an ovpn file:

Code: Select all

client
dev tun
proto udp
remote xxxx 1194
resolv-retry infinite
nobind
user nobody
group nogroup
persist-key
persist-tun
remote-cert-tls server
cipher AES-128-CBC
auth SHA256
comp-lzo
tun-mtu 1500
mssfix 1400
fragment 1300
verb 3
key-direction 1
script-security 2
up /etc/openvpn/update-resolv-conf
down /etc/openvpn/update-resolv-conf
I have the following server config:

Code: Select all

port 1194 
proto udp 
dh /etc/openvpn/dh2048.pem 
server 10.8.0.0 255.255.252.0 
ifconfig-pool-persist /etc/openvpn/ipp.txt 
keepalive 10 60 
ca /etc/openvpn/ca.crt 
cert /etc/openvpn/server.crt 
key /etc/openvpn/server.key 
crl-verify /etc/openvpn/crl.pem 
dev tun 
tun-mtu 1500 
mssfix 1400 
fragment 1300 
script-security 2 
tls-auth /etc/openvpn/ta.key 0 
tls-version-min 1.0 
route 10.11.0.0 255.255.0.0 
push "route 10.11.0.0 255.255.0.0" 
client-config-dir /etc/openvpn/ccd 
cipher AES-128-CBC 
auth SHA256 
comp-lzo 
persist-key 
status /etc/openvpn/openvpn-status.log 
verb 3
Here are the client logs:

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Thu Jul 23 22:21:05 2020 OpenVPN 2.4.4 x86_64-pc-linux-gnu [SSL (OpenSSL)] [LZO] [LZ4] [EPOLL] [PKCS11] [MH/PKTINFO] [AEAD] built on May 14 2019
Thu Jul 23 22:21:05 2020 library versions: OpenSSL 1.1.1  11 Sep 2018, LZO 2.08
Thu Jul 23 22:21:05 2020 NOTE: the current --script-security setting may allow this configuration to call user-defined scripts
Thu Jul 23 22:21:05 2020 Outgoing Control Channel Authentication: Using 256 bit message hash 'SHA256' for HMAC authentication
Thu Jul 23 22:21:05 2020 Incoming Control Channel Authentication: Using 256 bit message hash 'SHA256' for HMAC authentication
Thu Jul 23 22:21:05 2020 TCP/UDP: Preserving recently used remote address: [AF_INET]54.70.149.21:1194
Thu Jul 23 22:21:05 2020 Socket Buffers: R=[212992->212992] S=[212992->212992]
Thu Jul 23 22:21:05 2020 UDP link local: (not bound)
Thu Jul 23 22:21:05 2020 UDP link remote: [AF_INET]54.70.149.21:1194
Thu Jul 23 22:21:05 2020 NOTE: UID/GID downgrade will be delayed because of --client, --pull, or --up-delay
Thu Jul 23 22:21:06 2020 TLS: Initial packet from [AF_INET]54.70.149.21:1194, sid=a87a882e 76a8a999
Thu Jul 23 22:21:06 2020 VERIFY OK: xxxx
Thu Jul 23 22:21:06 2020 VERIFY KU OK
Thu Jul 23 22:21:06 2020 Validating certificate extended key usage
Thu Jul 23 22:21:06 2020 ++ Certificate has EKU (str) TLS Web Server Authentication, expects TLS Web Server Authentication
Thu Jul 23 22:21:06 2020 VERIFY EKU OK
Thu Jul 23 22:21:06 2020 VERIFY OK: xxxx
Thu Jul 23 22:21:06 2020 Control Channel: TLSv1.3, cipher TLSv1.3 TLS_AES_256_GCM_SHA384, 256 bit EC, curve: prime256v1
Thu Jul 23 22:21:06 2020 [server] Peer Connection Initiated with [AF_INET]54.70.149.21:1194
Thu Jul 23 22:21:07 2020 SENT CONTROL [server]: 'PUSH_REQUEST' (status=1)
Thu Jul 23 22:21:07 2020 PUSH: Received control message: 'PUSH_REPLY,route 10.11.0.0 255.255.0.0,route 10.8.0.1,topology net30,ping 10,ping-restart 60,ifconfig 10.8.0.18 10.8.0.17,peer-id 1,cipher AES-256-GCM'
Thu Jul 23 22:21:07 2020 OPTIONS IMPORT: timers and/or timeouts modified
Thu Jul 23 22:21:07 2020 OPTIONS IMPORT: --ifconfig/up options modified
Thu Jul 23 22:21:07 2020 OPTIONS IMPORT: route options modified
Thu Jul 23 22:21:07 2020 OPTIONS IMPORT: peer-id set
Thu Jul 23 22:21:07 2020 OPTIONS IMPORT: adjusting link_mtu to 1629
Thu Jul 23 22:21:07 2020 OPTIONS IMPORT: data channel crypto options modified
Thu Jul 23 22:21:07 2020 Data Channel: using negotiated cipher 'AES-256-GCM'
Thu Jul 23 22:21:07 2020 Outgoing Data Channel: Cipher 'AES-256-GCM' initialized with 256 bit key
Thu Jul 23 22:21:07 2020 Incoming Data Channel: Cipher 'AES-256-GCM' initialized with 256 bit key
Thu Jul 23 22:21:07 2020 ROUTE_GATEWAY 10.0.2.2/255.255.255.0 IFACE=eth0 HWADDR=08:00:27:bb:14:75
Thu Jul 23 22:21:07 2020 TUN/TAP device tun0 opened
Thu Jul 23 22:21:07 2020 TUN/TAP TX queue length set to 100
Thu Jul 23 22:21:07 2020 do_ifconfig, tt->did_ifconfig_ipv6_setup=0
Thu Jul 23 22:21:07 2020 /sbin/ip link set dev tun0 up mtu 1500
Thu Jul 23 22:21:07 2020 /sbin/ip addr add dev tun0 local 10.8.0.18 peer 10.8.0.17
Thu Jul 23 22:21:07 2020 /etc/openvpn/update-resolv-conf tun0 1500 1557 10.8.0.18 10.8.0.17 init
Thu Jul 23 22:21:07 2020 /sbin/ip route add 10.11.0.0/16 via 10.8.0.17
Thu Jul 23 22:21:07 2020 /sbin/ip route add 10.8.0.1/32 via 10.8.0.17
Thu Jul 23 22:21:07 2020 GID set to nogroup
Thu Jul 23 22:21:07 2020 UID set to nobody
Thu Jul 23 22:21:07 2020 WARNING: this configuration may cache passwords in memory -- use the auth-nocache option to prevent this
Thu Jul 23 22:21:07 2020 Initialization Sequence Completed

apache8080
OpenVpn Newbie
Posts: 16
Joined: Fri May 22, 2020 12:51 am

Re: Can't ping other clients when connected to vpn server

Post by apache8080 » Thu Jul 23, 2020 11:04 pm

Tried it again with two ubuntu clients and now when I ping I get the following response:

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PING 10.8.0.22 (10.8.0.22) 56(84) bytes of data.
From xxxx icmp_seq=1 Packet filtered
From xxxx icmp_seq=2 Packet filtered
Would my wifi setup cause this to happen?

apache8080
OpenVpn Newbie
Posts: 16
Joined: Fri May 22, 2020 12:51 am

Re: Can't ping other clients when connected to vpn server

Post by apache8080 » Thu Jul 23, 2020 11:43 pm

I can also ping the server (10.8.0.1) from each of the clients.

User avatar
TinCanTech
OpenVPN Protagonist
Posts: 7584
Joined: Fri Jun 03, 2016 1:17 pm

Re: Can't ping other clients when connected to vpn server

Post by TinCanTech » Thu Jul 23, 2020 11:47 pm

apache8080 wrote:
Thu Jul 23, 2020 10:50 pm
Any ideas on how to fix this?
:roll:

apache8080
OpenVpn Newbie
Posts: 16
Joined: Fri May 22, 2020 12:51 am

Re: Can't ping other clients when connected to vpn server

Post by apache8080 » Fri Jul 24, 2020 12:40 am

Seems like adding the client-to-client flag in the server config helped solve this issue.

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