Socket bind failed on local address address already in use

przemek

Hello everyone, Im new here and new with OpenVPN.

I have installed openvpn server on my Centos7 by:
https://www.cyberciti.biz/faq/centos-7-0-set-up-openvpn-server-in-5-minutes/

After install I run command systemctl start openvpn@server I got error like below. I think there is no any other openvpn services

Oct 15 10:07:44 psc-serv systemd: Cannot add dependency job for unit firewalld.service, ignoring: Unit is masked.
Oct 15 10:07:44 psc-serv systemd: Starting OpenVPN Robust And Highly Flexible Tunneling Application On server...
Oct 15 10:07:44 psc-serv openvpn: Thu Oct 15 10:07:44 2020 OpenVPN 2.4.9 x86_64-redhat-linux-gnu [Fedora EPEL patched] [SSL (OpenSSL)] [LZO] [LZ4] [EPOLL] [PKCS11] [MH/PKTINFO] [AEAD] built on Apr 24 2020
Oct 15 10:07:44 psc-serv openvpn: Thu Oct 15 10:07:44 2020 library versions: OpenSSL 1.0.2k-fips  26 Jan 2017, LZO 2.06
Oct 15 10:07:44 psc-serv systemd: Started OpenVPN Robust And Highly Flexible Tunneling Application On server.
Oct 15 10:07:44 psc-serv openvpn: Thu Oct 15 10:07:44 2020 CRL: loaded 1 CRLs from file crl.pem
Oct 15 10:07:44 psc-serv openvpn: Thu Oct 15 10:07:44 2020 ECDH curve prime256v1 added
Oct 15 10:07:44 psc-serv openvpn: Thu Oct 15 10:07:44 2020 Outgoing Control Channel Encryption: Cipher 'AES-256-CTR' initialized with 256 bit key
Oct 15 10:07:44 psc-serv openvpn: Thu Oct 15 10:07:44 2020 Outgoing Control Channel Encryption: Using 256 bit message hash 'SHA256' for HMAC authentication
Oct 15 10:07:44 psc-serv openvpn: Thu Oct 15 10:07:44 2020 Incoming Control Channel Encryption: Cipher 'AES-256-CTR' initialized with 256 bit key
Oct 15 10:07:44 psc-serv openvpn: Thu Oct 15 10:07:44 2020 Incoming Control Channel Encryption: Using 256 bit message hash 'SHA256' for HMAC authentication
Oct 15 10:07:44 psc-serv openvpn: Thu Oct 15 10:07:44 2020 TUN/TAP device tun1 opened
Oct 15 10:07:44 psc-serv openvpn: Thu Oct 15 10:07:44 2020 TUN/TAP TX queue length set to 100
Oct 15 10:07:44 psc-serv openvpn: Thu Oct 15 10:07:44 2020 /sbin/ip link set dev tun1 up mtu 1500
Oct 15 10:07:44 psc-serv openvpn: Thu Oct 15 10:07:44 2020 /sbin/ip addr add dev tun1 10.8.0.1/24 broadcast 10.8.0.255
Oct 15 10:07:44 psc-serv NetworkManager[867]: <info>  [1602749264.8738] manager: (tun1): new Tun device (/org/freedesktop/NetworkManager/Devices/8)
Oct 15 10:07:44 psc-serv openvpn: Thu Oct 15 10:07:44 2020 Could not determine IPv4/IPv6 protocol. Using AF_INET
Oct 15 10:07:44 psc-serv NetworkManager[867]: <info>  [1602749264.8764] device (tun1): state change: unmanaged -> unavailable (reason 'connection-assumed', sys-iface-state: 'external')
Oct 15 10:07:44 psc-serv openvpn: Thu Oct 15 10:07:44 2020 Socket Buffers: R=[212992->212992] S=[212992->212992]
Oct 15 10:07:44 psc-serv openvpn: Thu Oct 15 10:07:44 2020 TCP/UDP: Socket bind failed on local address [AF_INET][undef]:1194: Address already in use (errno=98)
Oct 15 10:07:44 psc-serv openvpn: Thu Oct 15 10:07:44 2020 Exiting due to fatal error
Oct 15 10:07:44 psc-serv openvpn: Thu Oct 15 10:07:44 2020 Closing TUN/TAP interface
Oct 15 10:07:44 psc-serv openvpn: Thu Oct 15 10:07:44 2020 /sbin/ip addr del dev tun1 10.8.0.1/24
Oct 15 10:07:44 psc-serv NetworkManager[867]: <info>  [1602749264.8783] keyfile: add connection /var/run/NetworkManager/system-connections/tun1.nmconnection (f9da174f-9335-4b2a-a508-263be5a0ee9e,"tun1")
Oct 15 10:07:44 psc-serv NetworkManager[867]: <info>  [1602749264.8786] device (tun1): state change: unavailable -> disconnected (reason 'connection-assumed', sys-iface-state: 'external')
Oct 15 10:07:44 psc-serv NetworkManager[867]: <info>  [1602749264.8790] device (tun1): Activation: starting connection 'tun1' (f9da174f-9335-4b2a-a508-263be5a0ee9e)
Oct 15 10:07:44 psc-serv NetworkManager[867]: <info>  [1602749264.8792] device (tun1): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'external')
Oct 15 10:07:44 psc-serv NetworkManager[867]: <info>  [1602749264.8812] device (tun1): state change: prepare -> config (reason 'none', sys-iface-state: 'external')
Oct 15 10:07:44 psc-serv NetworkManager[867]: <info>  [1602749264.8817] device (tun1): state change: config -> unmanaged (reason 'unmanaged', sys-iface-state: 'removed')
Oct 15 10:07:44 psc-serv systemd: openvpn@server.service: main process exited, code=exited, status=1/FAILURE
Oct 15 10:07:44 psc-serv systemd: Unit openvpn@server.service entered failed state.
Oct 15 10:07:44 psc-serv systemd: openvpn@server.service failed.

What I tried to do?

Command lsof -i | grep openvpn shows:

openvpn    4345 nobody    6u  IPv4 480484      0t0  UDP *:openvpn

I tried kill -9 4345 and restart openvpn@service, but problem still is.

My ifconfig output:

[root@psc-serv openvpn]# ifconfig
eno1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.8.101  netmask 255.255.255.0  broadcast 192.168.8.255
        inet6 fd7c:942a:1c27:d000:c9f0:d3a4:1696:483e  prefixlen 64  scopeid 0x0<global>
        inet6 fe80::6c4d:44f9:c786:48b8  prefixlen 64  scopeid 0x20<link>
        ether e0:07:1b:ff:da:4d  txqueuelen 1000  (Ethernet)
        RX packets 2462802  bytes 2483455326 (2.3 GiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 2717996  bytes 3373737608 (3.1 GiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device interrupt 16  memory 0xdf100000-df120000

enp1s0f0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether 00:26:55:d8:8a:ac  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device interrupt 18  memory 0xdf0a0000-df0c0000

enp1s0f1: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether 00:26:55:d8:8a:ad  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device interrupt 19  memory 0xdf040000-df060000

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 222  bytes 15100 (14.7 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 222  bytes 15100 (14.7 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

tun0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 1500
        inet 10.8.0.1  netmask 255.255.255.0  destination 10.8.0.1
        inet6 fe80::6039:3701:30f:6fc2  prefixlen 64  scopeid 0x20<link>
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 100  (UNSPEC)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 3  bytes 144 (144.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

[root@psc-serv openvpn]#

Im very intrested, why openvpn created tun0, but in the logs refer to tun1?

Output of server.conf:
port 1194
proto udp
dev tun
user nobody
group nobody
persist-key
persist-tun
keepalive 10 120
topology subnet
server 10.8.0.0 255.255.255.0
ifconfig-pool-persist ipp.txt
push "dhcp-option DNS 8.8.8.8"
push "dhcp-option DNS 8.8.4.4"
push "redirect-gateway def1 bypass-dhcp"
dh none
ecdh-curve prime256v1
tls-crypt tls-crypt.key 0
crl-verify crl.pem
ca ca.crt
cert server_zixbgjNGSC10rYC6.crt
key server_zixbgjNGSC10rYC6.key
auth SHA256
cipher AES-128-GCM
ncp-ciphers AES-128-GCM
tls-server
tls-version-min 1.2
tls-cipher TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256
client-config-dir /etc/openvpn/ccd
status /var/log/openvpn/status.log
verb 3

I will be greatfull for any tips.

Your faithfully,
Przemek.

TinCanTech

przemek wrote TCP/UDP: Socket bind failed on local address [AF_INET][undef]:1194: Address already in use (errno=98)

przemek wrote I think there is no any other openvpn services

przemek wrote I run command systemctl start openvpn@server

Try using only openvpn-server@server

przemek

Hello again.

After some research...

After install OpenVPN server by script, I run command lsof -i | grep openvpn and got result like:

openvpn    2817 nobody    6u  IPv4 166261      0t0  UDP *:openvpn

So, openvpn cannot start, because it is runnning...

I killed that process by: kill -9 2817 and again run lsof commend - the process was gone, but few moments later it run again by self :shock:. So, I killed it again and fast run command systemctl start openvpn@server - seems to by ok.