Subnetting with Sunlink INR?

[Frank W. Peters]

Hello,

We are having a problem with Suns Sunlink Internetwork Router product that
I hope someone here can help with.

     Below is a drawing of the relevant systems.

      (Building Backbone, 130.18.64.0)
________________________________________
                   |
                   |(130.13.64.7)
             -------------
             |           |      (Sunlink INR link @9600bps)
             |  Athena   _________________________________________
             |           |                                       |
             -------------                                       |
                   |(130.18.160.1)                               |
                   |                                             |
       ----------  |                                             |
       |        |  |                                        -------------
       |  A1    |_ |(130.18.160.2)                          |           |
       |        |  |                                        | Corona    |
       ----------  |                                        |           |
                   |                                        -------------
                   |                               (130.18.240.4)|
                   |                                             |
                                     ---------------------------------------
                                      (Building Backbone, 130.18.240.0)


Our 130.18 network is subnetted (mask ffffff00).  Athena has two ethernet
interfaces as well as the ptp (point to point) link to Corona in another
building off campus.  All systems on our campus can get to systems on
Athena's ethernet interfaces (that is, Athena will route packets between
its two ethernet interfaces).  In addition, all systems can get to Corona.
Both Corona and Athena are Sun 4/260s running SunOS 4.0.

Now, the problem.  there are several subnets in the Corona building.  We
would like to add explicit routes to these subnets through Corona.  That
is, we would like to put the following explicit route in Athena:

/usr/etc/route add 130.18.8.0 Corona 1

Where 130.18.8.0 is a subnet in the Corona building.  The problem is that
Athena treats 130.18.8.0 as a host number, not a network number.  With the
INR link down Athena recognizes the route as a subnet route.  If we do an
explicit route to a host via

/usr/etc/route add 130.18.8.162 Corona 1

we can succesfully connect from athena to 8.162 so we know that the
routing in the Corona building is fine (Corona's routing is much simpler
since it has a default route to the ptp link).

So my question is, why does Athena act subnetted when Sunlink isn't running
and unsubnetted when Sunlink is up?

Here are Athena's ifconfigs (with Sunlink running):

athena0/lgt> ifconfig ie0
ie0: flags=63<UP,BROADCAST,NOTRAILERS,RUNNING>
	inet 130.18.160.1 netmask ffffff00 broadcast 130.18.160.255
athena0/lgt> ifconfig ie1
ie1: flags=63<UP,BROADCAST,NOTRAILERS,RUNNING>
	inet 130.18.64.7 netmask ffffff00 broadcast 130.18.64.255
athena0/lgt> ifconfig ptp0
ptp0: flags=51<UP,POINTOPOINT,RUNNING>
	inet 130.18.64.7 --> 130.18.240.4 netmask ffffff00

Any suggestions?  Anybody successfully using Sunlink?

                               Thanks
                               Frank Peters

| Systems & Networks Programmer      |   Mississippi State University  |
| Phone:    (601) 325-2942           |   Computing Center and Services |
| Internet:  peters at CC.MsState.Edu   |   Post Office Drawer CC         |
| BITNET:    PETERS at MSSTATE.BITNET   |   Mississippi State, MS.  39762 |