[OpenVPN home] [Date Prev] [Date Index] [Date Next]
[OpenVPN mailing lists] [Thread Prev] [Thread Index] [Thread Next]
Google
 
Web openvpn.net

Re: [Openvpn-users] OPenVPN clients don't see each other on TAPbridge


  • Subject: Re: [Openvpn-users] OPenVPN clients don't see each other on TAPbridge
  • From: Denis Jedig <dj@xxxxxxxxxxxx>
  • Date: Mon, 5 Mar 2007 19:18:11 +0100

On Mon, 5 Mar 2007 10:12:34 +0100 Serge Wautier wrote:

> Because if bridges don't do that, I confess I don't see the point:
> TAP/bridge OpenVPN clients (and LAN clients) appear on the same subnet.
> Pardon my ignorance but why would that be interesting if the subnet members
> can't see each other?

OpenVPN does have the concept of a "server" and a "client" side. If you use
a TAP configuration, everything will be forwarded from the server side of
your network to every client side and vice versa, but not amongst the
client networks unless you use the client-to-client option. I am not sure
about the rationale but I believe it would be for historical or symmetrical
reasons.

In a TUN configuration having traffic routed among client nets before the
kernel sees it is a quick & dirty solution to make "everyone sees everyone"
happen. However, this does not make much sense in most cases - usually you
have VPN clients needing to access a specific network behind the central
VPN gateway without the need for the clients to communicate with each
other.

As you want to filter your client-to-client traffic, you will have to
route, not bridge, your traffic through the kernel routing tables. You will
need to remove the client-to-client option in this case, make sure the
kernel routing works correctly and set up your netfilter rules.

What was the reason you decided to use a TAP configuration in the first
place?

-- 
Denis Jedig
syneticon networks GbR             http://syneticon.net/service/

______________________
OpenVPN mailing lists
https://lists.sourceforge.net/lists/listinfo/openvpn-users