Re: Routing through an openvpn tunnel.

Tom Eastep
Fri, 18 Jul 2008 18:18:36 -0000

PETER EASTHOPE wrote:
> Folk,
>
> A tunnel as described in openvpn.man, Example  2
> works between my home 10.4.0.1 and work 10.4.0.2
> machines.
> "ping 10.4.0.1" from 10.4.0.2
> and
> "ping 10.4.0.2" from 10.4.0.1
> succeed as expected.
>
> 10.4.0.1 and peasthope.yi.org both refer to the
> machine at home where mail is accumulated by fetchmail.
> A machine on the LAN connected to 10.4.0.2 can
> retrieve mail from peasthope.yi.org via the Internet.
> But, of course, I prefer to retrieve through the tunnel.
>
> As I understand, the section of openvpn.man entitled
> "Routing" addresses this, but here, routing should be
> specified using shorewall rather than the iptables
> command in openvpn.man.

No and no. You don''t specify routing in Shorewall or using iptables.
You
specify routing via OpenVPN.

> I''ve read
> http://www.shorewall.net/OPENVPN.html
> and remain uncertain about routing.
> Are the policies
> #SOURCE        DEST          POLICY          LOG LEVEL
> loc            vpn           ACCEPT
> vpn            loc           ACCEPT
> sufficient to get the routing?

No.

> Is routing a separate matter?

Yes

There are only two cases where Shorewall gets involved in routing:

a) Entry in /etc/shorewall/proxy_arp with the NOROUTE column set to
''Yes''.
Shorewall will create a host route to the internal system.
b) Entry in /etc/shorewall/providers. Shorewall creates an additional
routing table and some rules and may replace the default route in the main
table.

Again, those are the only instances where Shorewall is involved in route
configuration. Please see http://www.shorewall.net/Shorewall_and_Routing.html.

-Tom
--
Tom Eastep    \ Nothing is foolproof to a sufficiently talented fool
Shoreline,     \ http://shorewall.net
Washington USA  \ teastep@shorewall.net
PGP Public Key   \ https://lists.shorewall.net/teastep.pgp.key



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