> On Wed, 6 Nov 1996, Stephen Zedalis wrote:
> >
> > On Wed, 6 Nov 1996, John-David Childs wrote:
> >
> > > Now, one of these remote locations needs an *additional* 30 IP addresses
> > > routed to the Ethernet interface!
>
> Point of information needed. What is providng the remote access link,
> the PM-2ER via the WAN port?
> ...
Yes...a PM2ER via the WAN port.
> > > I *thought* that
> > > even though the PM's don't do VLSM that I would be able to route this
> > > second subnet to it via static routing.
> ...
> > > but the customer is
> > > unable to see it or get any machines in the second subnet to see the PM
> > > (who's ethernet address is in the first subnet). Is there anything I can
> > > do to get the second subnet recognized by computers on the remote PM's
> > > ethernet port???
>
> Depends on the remote router. If it is the PM-2ER you are out of luck
> since the PM can not do secondary netowrk addressing.
>
That's what I've been hearing...I've been waiting for OSPF ;-) (I was
originally going to beta-test OSPF for the PM's, but all of my sites are
"critical" and the few times I tried running it I hosed my network
(undoubtedly my lack of OSPF-speak) so I gave up and decided to wait for
more experienced net-guru's to put it through the paces ;-)
> > > On the IRX (local):
> > > add netmask XXX.YYY.ZZZ.0 255.255.255.248
> > > route add XXX.YYY.ZZZ.64 XXX.YYY.WWW.2 1 (ethernet subnet...this works)
> > > route add XXX.YYY.ZZZ.32 XXX.YYY.WWW.2 1 (modem subnet..also works)
> > >
> > > route add XXX.YYY.ZZZ.96 XXX.YYY.WWW.2 1 (SECOND SUBNET of 30 IP's)
> > > Traceroutes to XXX.YYY.ZZZ.97-126 DO make it to XXX.YYY.WWW.2!!
> > >
> > > I have also tried
> > > route add XXX.YYY.ZZZ.96 XXX.YYY.ZZZ.65 (the IP address of the remote PM
> > > ethernet interface)
> > >
> > > I entered the same netmask table and routing commands on the remote PM as
> > > shown above...no dice. I cannot ping/traceroute to any IP on the second
> > > subnet. Do I have to renumber the original 30 IP's to a .192 network???
> > > Just say NO! :-)
>
> NO! Not unless you renumber the ENTIRE XXX.YYY.ZZZ.0 network to a .192
> subnet mask. (SHUDDER)
>
Shudder...then that's what I'll do :-(
> It is not a RIPv1 limitation. It is the fact that the hosts and routers
> are traeting the subnets as separate networks and it is EXACTLY like two
> class Cs on one wire.
>
> > Why? Because when one machine doesn't know
> > (or forgets) the ethernet MAC address of another machine what does it do?
> > It sends out an ARP broadcast message to the net (in this case subnet)
> > using its own network's broadcast address which the other network's
> > machines aren't listening to.
>
> Absolutely correct.
>
So can I get around this by setting up the PC's with a .192 subnet mask and
just not assign the network/broadcast IP's...i.e. the PM thinks the network
is a .224 (as someone pointed out a 30-host network is .224 NOT .248), but
the PC's think it's a .192 and thus send ARP requests to the proper network
address)
Currently: XXX.YYY.ZZZ.64 (network) subnet .224
XXX.YYY.ZZZ.65-94 (usable)
XXX.YYY.ZZZ.95 (broadcast)
And a second (contiguous) .224 network (.96 broadcast, .97-.126, .127)
is routed to the remote PM2ER but invisible to the PC's because of the
above discussion.
So now, I want to set all of the PC's to .192 subnets...then they'll ALL
be visible to the .65 IP address (PM Ethernet port). This probably won't
work either (I have no way yet of verifying that the PM Ethernet port can
see the second subnet....I only know that packets are being routed to the
interface)
> > The remote Livingston has static routes in
> > its tables to route both subnets to its ethernet port I assume.
YES.
> > It may or
> > may not route in this case, since all traffic for one subnet would come in
> > and the have to go out the same interface as destination.
This is the big question ;-)
> > If this doesn't
> > work you might consider setting up a linux or whatever gateway machine
> > that has IP forwarding turned on, IP aliasing for both subnets, gated,
> > and/or proxy arping for each subnet. A little more of a pain, but you
> > have finer grain control over what is going on with routing.
>
I'm probably going to have to dump the Livingston's for "complex" routing
issues such as these and go with a Cisco (but jeez Livingston's are soooo
much easier to configure ;-) (NO RELIGIOUS FLAMES, plz)
> > You were clear that your packets were getting to the remote portmaster,
> > you weren't clear in whether the remote portmaster knew what to do with
> > the packets once it got them. Does it have the proper static route
> > tables?
>
> Static routes aren't going to help as there isn't a router to send the
> second subnet to. It is probably sending the packets back as
> 'unreachable'.
>
Yep...that's what's happening now...heck a simple static route command on a
Win95 box connected on the second subnet might do the trick ;-)
> HTH!
>
> JGT
> --
> John G. Thompson Livingston Enterprises Inc. Phone: (800) 458-9966
> JOAT(MON) 6920-220 Koll Centre Pkwy. Fax: (510) 426-8951
> support@livingston.com Pleasanton, CA 94566 http://www.livingston.com
>
>
John-David Childs www.marsweb.com/www.ism.net
System Administrator Internet Services Montana (406)721-6277
& Network Engineer M@RSWeb - Montana's PREMIER Web Site
"I used up all my sick days...so I'm calling in dead"