On 1/20/23, David Gwynne <da...@gwynne.id.au> wrote: > On Fri, Jan 20, 2023 at 11:09:47AM -0800, patrick keshishian wrote: >> Hello, >> >> I am trying get a new ISP setup working. The Router is >> causing some pain. There is a /28 public block assigned. >> The DSL router can't be configured in transparent bridge >> mode (they say). It holds on to one of the /28 addresses. > > i'm sure they say that, but that doesn't mean it's impossible. this > will be a lot easier and more useful if you can get a dsl modem > into bridge/transparent mode and do all the routing on your own > box.
OK. So the situation was a bit worse than I had actually anticipated. After I got the described setup configured I noticed that the DSL Router/Modem wouldn't send out any traffic unless it had an arp entry for the source. e.g., nat-to an unassigned IP from the /28 wouldn't go out. Again, in my limited networking knowledge, it meant I had to do proxy arp entries for /28 public IPs in the $dmz. This was quite frustrating. So I started poking around in the DSL Router/modem settings (cuing off your "doesn't mean it's impossible") and I have it now acting as a transparent bridge! I spent most of Tues on the phone with their techs, and I was assured that is not possible/unsupported. Now maybe they actually meant "unsupported" mode as far as their support is concerned. But things seem to running as expect (so far)! So thanks for the bit of "encouragement"! > that would also give you the option to do fun stuff like NOT putting > the /28 onto an ethernet network so you could you use all 16 of the > IPs on dmz hosts instead of losing some to network/broadcast/gateway. I am curious how you would go about doing what you suggest: Using all 16 of /28. Thanks for your reply, --patrick >> The setup looks something like this: >> (and hopefully the ascii "art" remains intact from gmail) >> >> ( internet ) >> | >> | [WAN IP] >> +-----o------+ >> / DSL ROUTER / <-- Transparent bridge mode NOT possible >> +-----o------+ >> | [ one of /28 Public IPs = $dslgw_ip ] >> | >> | >> | $ext >> +-----o------+ >> | | >> | OpenBSD/pf o--- ( rest of /28 Public IP network ) >> | | $dmz (DMZ: httpd, smtpd, ...) >> +-----o------+ >> $lan | [10.x.x.1] >> | >> ( 10.x.x.x network ) >> >> >> As far as networking goes, I need to be spoken to as if I'm >> a fledgling. >> >> I want to do the obvious: use OpenBSD/pf(4) to: >> - Filter traffic from $ext to $dmz >> - Filter traffic from $dmz outbound >> - Filter traffic from $lan (10.x.x.x) to $dmz >> - NAT traffic from $lan (10.x.x.x) outbound to internet >> >> >> I'm bridge(4)-ing $ext and $dmz. Which means I must give >> one of the /28 public IP addresses to either $ext or $dmz >> to be able to do: >> >> # route add default $dslgw_ip >> >> (!?) >> >> Am I missing something? >> Is there a better way to configure things? >> >> Thanks, >> --patrick >> >
