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items: Openvpn Internet issue
items: Re: Openvpn Internet issue

Openvpn Internet issue
type: item
description: Hello Folks, I have Openvpn installed in a Ubuntu 8.10 VE. I can ping the server and browse to the server vpn IP address from my Windows XP client but there is no internet. My configuration is as follows: Server IP: 1.2.3.4 (real IP replaced for security reasons) Server VPN Network: 10.50.50.0/24 Server VPN IP: 10.50.50.1 XP Client VPN IP: 10.50.50.6 Searching around I found that I needed to do some kind of masquerading so I tried in the VE: root@openvn2:~# iptables -t nat -A POSTROUTING -i 10.50.50.0/24 -o venet0 -j SNAT --to 1.2.3.4 FATAL: Could not load /lib/modules/2.6.18-92.1.18.el5.028stab060.8PAE/modules.dep: No such file or directory iptables v1.4.0: can't initialize iptables table `nat': Table does not exist (do you need to insmod?) Perhaps iptables or your kernel needs to be upgraded. Would this be help to my problem? http://wiki.openvz.org/Using_NAT_for_container_with_private_ IPs The container is using a public IP. Any help would be most appreciative. Thanks Sammy
creator: sammy08
date: 2009-05-21T08:26:21-00:00

Re: Openvpn Internet issue
type: item
description: Either needed iptables modules are not loaded at all, or they are loaded _after_ you started vz service. So make sure you load needed iptables modules (i.e. ipt_nat or whatever) _before_ you start /etc/init.d/vz service.
creator: kir
date: 2009-05-21T19:09:47-00:00

Re: Openvpn Internet issue
type: item
description: kir wrote on Thu, 21 May 2009 15:09 Either needed iptables modules are not loaded at all, or they are loaded _after_ you started vz service. So make sure you load needed iptables modules (i.e. ipt_nat or whatever) _before_ you start /etc/init.d/vz service. Kir, I am not sure if I understand you correctly but IPTables is running on the hardware node and I have it running in the VE. The only command that wouldn't work is this: iptables -t nat -A POSTROUTING -i 10.50.50.0/24 -o venet0 -j SNAT --to 1.2.3.4
creator: sammy08
date: 2009-05-21T19:40:29-00:00

Re: Openvpn Internet issue
type: item
description: sammy08 wrote on Thu, 21 May 2009 23:40 IPTables is running on the hardware node and I have it running in the VE. OK, a little longer explanation. Functionality of iptables is implemented in kernel, by the kernel modules (named ip_*, ipt_*, iptables_* nf_* etc.). Such modules are loaded during system bootup, and they provide different iptables filters, policies, etc. For example, SNAT functionality is provided by ip_nat, ip_conntrack, iptable_nat and probably some other modules. OpenVZ functionality is also (partially) provided by the kernel modules (named vz*). Those modules are loaded by /etc/init.d/vz script during system bootup. If you need to use functionality of some iptables modules from inside a VE, you need to make sure the modules you need are loaded before /etc/init.d/vz is started. How to implement that depends on your distro. In most cases /etc/init.d/vz script itself contains code to (pre)load needed iptables modules. In that case the list of modules to be loaded is set by IPTABLES variable in /etc/vz/vz.conf file. So what you need to do is 1. Find out what modules do you need. You can do so by running lsmod on the host system, then running the iptables command that you try to run in VE (and it will load the required modules automatically), and the running lsmod again for the second time. Now, compare the output of two lsmod runs and find out the new modules which has just been loaded. Most probably this is ip_nat, but YMMV. 2. Add the names of those modules into IPTABLES in /etc/vz/vz.conf 3. Run /etc/init.d/vz restart. 4. Check in VE that it's working. Finally, the error you see is caused by the fact that iptables utility is smart enough so it tries to load some iptables modules if those are not yet loaded. Of course you can not do that from within a VE (for security reasons) so iptables tries to load modules and it fails. (Note that this explanation is a little simplified but correct).
creator: kir
date: 2009-05-21T20:56:00-00:00