IPSec SPD

[Brian A Seklecki (Mobile)]

On Fri, 2007-10-26 at 16:55 +0700, Victor Sudakov wrote:
> Colleagues, 
> 
> Suppose our remote office uses the 10.1.1.0/24 network, and the whole
> company uses the 10.0.0.0/8 network.
> 
> How do we set up the SPD entries to encrypt traffic to the
> headquarters and back?
> 

I do hub a spoke config just like this using OpenBSD and Cisco VPN3k
using /24s at the edge and /16s at the core.  All works well.  Better
than full mesh.

I just ran into a small bug with the new Ipsec stack in OpenBSD where I
had to have a "null" policy -- otherwise traffic with destination routes
for the locally connected /24 would accidentally be fwd'd across the
tunnel (because ipsec tunnel evaluation happens earlier in ip_output(),
which is non-standard)

~BAS

> spdadd 10.0.0.0/8 10.1.1.0/24
> ...
> spdadd 10.1.1.0/24 10.0.0.0/8
> ...
> 
> is not a good idea, is it? 
> 
> Thanks in advance for any input.
>