On Thu, Jul 24, 2003 at 05:10:38PM +0200, Roberto Nibali wrote:
> Hi,
>
> >No, to clarify I had to make the firewall rules to the clustered service
> >stateless. I log all blocked traffic, so I would have seen it if it
> >was just getting blocked. But it wasn't getting blocked, though, it
> >just kind of disappeared after going on the bridge. After I
> >allowed traffic without keeping state from my client machine to the
> >cluster node it started working (except for the mtu).
>
> So you're saying that pf can't handle fragments with states?
I looked into this more. The problem was I didn't keep state on all
interfaces that the clustered traffic would pass through on that
router/bridge. After I put "keep state" on all interfaces that would
see that traffic it started working, so it is possible to do a stateful
firewall.
> >I set the mtu on the link level. How do you change it at the routing
> >level? That would definitely be desirable. I'm trying to figure out
>
> When you set up the route, you specify the mtu, something like this:
>
> ip route add 192.168.0.0/24 via 10.10.10.1 dev eth1 mtu 1280
>
> and you check it by its slow cache entry:
>
> ip -o -s -s route show cache
>
> It's extremely simple and straightforward.
I found an even better way. I put this in /etc/pf.conf on both openbsd
boxes and all traffic that gets passwd over the bridge is automatically
changed to have a correct mss of 1240.
scrub on gif0 no-df max-mss 1240
So after this little bit of magic no changes are needed on the real
servers, and I'm pretty sure that you can have a failover director in
the other location, too, which I need to test to make sure it works
sometime because I have a director in each location.
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