How to set a custom route source in openvpn

Question

I have a simple openvpn configuration.

remote 1.2.3.4
dev tun
ifconfig 10.74.1.13 10.75.2.1
secret static.key
route 10.75.0.0 255.255.0.0
keepalive 10 60

When the link come up, the routing table is updated.

[me@localhost ~]$ ip route
10.75.2.1 dev tun0  proto kernel  scope link  src 10.74.1.13
10.21.54.0/24 dev eth0  proto kernel  scope link  src 10.21.54.133
10.74.0.0/16 dev br0  proto kernel  scope link  src 10.74.0.13
169.254.0.0/16 dev eth0  scope link  metric 1002
169.254.0.0/16 dev br0  scope link  metric 1004
**10.75.0.0/16 via 10.75.2.1 dev tun0**
default via 10.21.54.2 dev eth0

When the packets arrive at the other end (10.75.2.1) the source ip address is 10.74.1.13. But I want the source address to be 10.74.0.13. I can run this command

[me@localhost ~]$ sudo ip route change 10.75.0.0/16 via 10.75.2.1 src 10.74.0.13

to make this change. Now the source address is what I want it to be (10.74.0.13). The last part of the puzzle is what my question is all about.

How can I get OpenVPN to set the route up this way when the link is first established?

Your vpn server should have a "push route ..." statement in the configfile so that the client's route is set correctly. — ott--, Jul 23 '13 at 21:09

score 1 · Accepted Answer · edited Aug 09 '13 at 14:33

1

I can't get access to my server. But I remember that you can make a custom ifconfig or route config file for every PC that make a connection to the VPN server.

edited Aug 09 '13 at 14:33

slm

7,615
16
56
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answered Jul 23 '13 at 18:22

John Smith

36
1

Right. openvpn has the --up option. I'll check it out. – Michael Closson Jul 23 '13 at 18:27
Maybe you could show/explain how to do this? – slm Aug 09 '13 at 14:33
2

The parameter `route-up` seems to work. Rather than spec the route w/ `route 10.75.0.0 255.255.0.0`, I used `route-up "/sbin/ip route add 10.75.0.0/16 via 10.75.2.1 src 10.74.0.13"` – Michael Closson Aug 21 '13 at 16:32

score 1 · Answer 2 · answered Jul 23 '13 at 20:47

1

I'm not sure about openvpn but pptpd allows you to store your user accounts an a mysql database and specify a framed ip address for each user when using the freeradius-mysql plugin for pptpd.

Here is a configuration tutorial:

http://www.pmoghadam.com/homepage/HTML/slackware-12.2-poptop-freeradius-mysql-pppoe-server.html

answered Jul 23 '13 at 20:47

andrew

131
5

Wow. I had no idea that pptpd allow such flexibility. Thank for the link! – Michael Closson Aug 21 '13 at 16:39

How to set a custom route source in openvpn

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