SUNOS 3.4 problem

[Aloys Roes]

We ran into a problem with TCP/IP on SUNOS 3.4. A number of these systems
can no longer communicate to the outside world. This problem suddenly
popped up last week. None of the system administrators have changed
anything relevant lately (they say). 

The configuration is as follows:


               outside world i.e.:
                   network 130.143.0.0
                   network 130.145.0.0 etc ...
                   subnet 130.144.60.0
                   subnet 130.144.61.0 etc ...                  |
                       \  |  /                    |-------+-----+----|
                        \ | /                             |
                      +---+---+           +-------+   +---+---+
                      | cisco |           | Other |   | Other |
                      | router|           |Systems|   |routers|
                      +---+---+           +---+---+   +---+---+
                          | 254               | ...       | ...
      |-------------------+---------+---------+-----------+------|
        130.144.1.x             ie1 | 115
                                +---+---+
                                | Sun A |
                                |  3.4  |
                                +---+---+
              130.144.20.x      ie0 | 99
		|-------+-----------+--------------+---------|
                    ie0 | 101                  ie0 | 102
                    +---+---+                  +---+---+
                    | Sun B |                  | Sun C |
                    | 4.0.3 |                  |  3.4  |
                    +-------+                  +-------+

The subnet mask for all systems is set to 255.255.255.0.

The problem is that the Sun A and C (both SUNOS 3.4) cannot communicate to
systems in their own network but different subnet meaning that it does not
take the correct decision on whether to use ARP or routing. e.g SUN A can
send ICMP echo requests and receives replies from hosts in subnet
130.144.1 and 130.144.20. Also PING to hosts in network 130.145 and
130.143 works fine.  However when a PING request is made to a host in a
remote subnet e.g.  host 130.144.60.80, the SUN does not send the packet
to the cisco router but does an ARP request on the ethernet with interface
ie0 instead.  Strangely enough a PING from host 130.144.60.80 gets a reply
when sent to 130.144.1.115 but not when sent to 130.144.20.99. 

SUN A has 'routed' running and the routing tables look ok. Rebooting makes
no difference. Adding a default gateway also shows no result.  Only
netstat -i does not show subnets but has never done that under SUNOS 3.4. 

Does anyone have suggestions. Any comment will be appreciated.

Thanks in advance,

Aloys Roes, Philips Components, Building BC-136, |  Tel. : + 31 40 72 30 62
P.O.Box 218, 5600 MD Eindhoven, The Netherlands  |  Email: roes at seri.philips.nl