IP assigned randomly

imjebran

Hello,

My config file is.

tls-server
port 53
proto udp
topology subnet
dev tun
client-cert-not-required
username-as-common-name
ca "C:\\Program Files\\xxxx.crt"
cert "C:\\Program Files\\xxxxr.crt"
key "C:\\Program Files\\xxxxx.key"
dh "C:\\Program Files\\xxxxx.pem"
server xx.xxx.xx.224 255.255.255.224
push "redirect-gateway def1 bypass-dhcp"
cipher AES-256-CBC
push "dhcp-option DNS 208.67.222.222"
push "dhcp-option DNS 8.8.4.4"
duplicate-cn
keepalive 10 120
tls-auth xxx.key 0 # This file is secret
comp-lzo
persist-key
persist-tun
status openvpn-status.log
management localhost 7505
log-append openvpn.log
verb 3
mute 20
route-method exe
script-security 3
auth-user-pass-verify "C:/xx/xxx.exe C:/xxx.php" via-file

How can I set openVPN assigned randomly IPs from this pool xx.xxx.xx.224 255.255.255.224.

Regards,
Jebran.

janjust

normally, OpenVPN assigns addresses linearly; if you want to make it random you can use a 'client-connect' script to assign a random IP address . In this case you'd need to keep track of the assigned IPs yourself (in order to prevent the same IP from being handed out twice).

imjebran

Hello Janjust,

Can you please advise any link from where I can get idea to apply this.

Regards,
Jebran.

janjust

for Windows servers, I have no idea - my best bet would be some PowerShell script , or perhaps even PHP - you seem to be using that already.

imjebran

Thanks for the advise, can you provide any example script of linux based OpenVPN server.

janjust

I'd use 'topology subnet' to assing IPs and the rough idea for the client-connect would be something like

#!/bin/bash

num_attempts=10

while [ $num_attempts -gt 0 ]
do
  POOL=192.168.100
  # generate the last IP digits randomly between 16 and 48
  RANDIP=$POOL.`echo 16+32*$RANDOM/32768 | bc`

  # not taken yet?
  if [ ! -r /etc/openvpn/ip-pool/$RANDIP ]
  then
    # take it
    touch /etc/openvpn/ip-pool/$RANDIP
    # write out the ifconfig line to $1 which is picked up by openvpn
    echo "push \"ifconfig $RANDIP 255.255.255.0\"" > $1
  fi

  let num_attempts--
done

echo "ERROR: could not assign a random address in 10 attempts - aborting!" 1>&2

and a 'client-disconnect' would delete the assigned IP:

#!/bin/bash

rm -f /etc/openvpn/ip-pool/$ifconfig_pool_remote_ip

imjebran

it will be helpful for us,

Thanks,
Jebran.