help: address already in use

0615

Our ISP provided me a static one IP (ex. 1.2.3.4) which I intended to use like so

tcp - 1.2.3.4 with lport 443
udp - 1.2.3.4 with lport 1194

my server is a newly formatted centos distro. so supposedly I have not yet used any ports.

but when I run openvpn /etc/openvpn/udpserver.conf or
openvpn /etc/openvpn/tcpserver.conf

I get the error address already i use. even if I change the ports 443 and 1194 to any port number, I get the same error. Why is this and how to solve this? I tried to check with netstat -plan | grep :portnumber, there is no result because I port is not yet used. But why am I getting this error.

Any way for further information, this computer is not a vps, but a stand-alone computer like a dedicated server. with eth0 port and I assigned the eth0 with IP address 192.168.1.13 because this commputer is part of the local network. its is like this diagram:

internet --> modem --> dlink router --> dedicated server (192.168.1.13)

please kindly assist me.

mwandelaar

Can you post your server-config here, just to be sure there are no error's in your config.

Assuming your configfile is correct:
Is there anything like apparmor / SElinux /GrSecurity installed on the system?
These kernelspace utilities can even block the root-user from opening ports.

0615

mode server
tls-server
local x.x.x.x
port 1194
proto udp
dev tun
ca /etc/openvpn/keys/ca.crt
cert /etc/openvpn/keys/server.crt
key /etc/openvpn/keys/server.key
dh /etc/openvpn/keys/dh1024.pem
plugin /etc/openvpn/keys/openvpn-auth-pam.so /etc/openvpn/keys/login
client-cert-not-required			
username-as-common-name				
topology subnet					
server 50.8.0.0 255.255.240.0 			
ifconfig-pool-persist /etc/openvpn/ippudp.txt 60
tun-mtu 1500
tun-mtu-extra 32	
mssfix 1400
keepalive 5 120
ping-timer-rem
persist-tun
persist-key
cipher BF-CBC
auth SHA1
comp-lzo
inactive 99999999					
verb 3

I believe there is no error on this code to produce the address already in use.

I am not sure if yum update automatically installs apparmor / SElinux /GrSecurity on centos 6.4
but I have not manually chosen to install those packages that you mentioned.

maikcat

2 things

1)post the output of sestatus
if its enforcing then SElinux is blocking things..better switch it to permissive

2)is your lan ip part of 50.8.0.0/24 range?

Michael.

0615

1. I disabled selinux and

2. my lan is nt part of 50.8.0.0/24

maikcat

server logs?

also

ps ax | grep openvpn

before you start openvpn...

Michael.

0615

Ok maikcat. I cant try nw coz im at home. I will get back on monday.