From: iscyeoak@nuscc.nus.sg (YEO ANN KIAN)
Subject: FDDI and RPC
Organization: National University of Singapore
Date: Wed, 9 Sep 1992 09:11:16 GMT


Re: FDDI and RPC

We have a RS6000/560 running AIX 3.2.
It has 2 ethernet interfaces (en0 & en1) and 2 FDDI interfaces (fi0 & fi1).

Currently only the two ethernet interfaces en0 and en1 are enabled;
the two FDDI interfaces fi0 and fi1 are disabled.
We set the netmask and broadcast for all the interfaces as 255.255.255.0
and 137.132.x.255 respectively (where x is 85, 86, 87 or 88).

We would like to connect this AIX machine to a DEC5000 machine
forming a private FDDI ring between these two machines.
After we have connected the FDDI cables between the machines,
we enable the fddi interfaces on both machines. 
We also set the routing table of both machines such that these two
machines can communicate using this particular routing entry.

On the AIX machine, fi0 is enable.
Its routing table is as follows:

default          137.132.86.1       UG         17  1812639  en1
loopback         localhost          U           5  5415096  lo0
137.132.86       ibmunx             U         608 17124843  en1
137.132.87       ibmunx             U          64  2829747  en0
decfddi          ibmfddi            UH          0      525  fi0  <----A

After the routing table is set, both machines can telnet to each other using
the routing entry A. NFS mounting seems to be fine between these two machines.
But, rwall, rusers & ypwhich do not work anymore.
("ypwhich" hung; "ypwhich -m" worked fine; rwall and rusers simply hung)
They were all working fine before that!

We leave the fi0 enable overnight. Sometimes the following day, 
the whole AIX system hung until we have disabled fi0 (using ifconfig)
and all things go back to normal. 
ypwhich, rwall and rusers now work.
We suspect that it could be the RPC and NIS programs went astray after
the fi0 has been enable (somehow).

This only happens to our AIX machine.
The other DEC5000 workstation has no such problem.
This is rather strange.
Appreciate if anybody can help.

--
Yeo AnnKian, Systems Programmers, DISCS, NUS, Singapore
yeoak@iscs.nus.sg


"netstat -i" shows:

Name  Mtu   Network     Address         Ipkts    Ierrs Opkts    Oerrs Coll 
lo0   1536  <Link>                       5534746     0  5534746     0     0
lo0   1536  loopback    localhost        5534746     0  5534746     0     0
fi0*  4352  <Link>                           820     0      531     0     0
fi0*  4352  137.132.88  ibmfddi              820     0      531     0     0
en0   1500  <Link>                       5926576 322834  2828757     0     0
en0   1500  137.132.87  ibmunx           5926576 322834  2828757     0     0
en1   1500  <Link>                      21867896 33786 19752034  1359     0
en1   1500  137.132.86  ibmunx          21867896 33786 19752034  1359     0
fi1*  4352  <Link>                        876900     0        0     0     0
fi1*  4352  137.132.85  137.132.85.6      876900     0        0     0     0

"netstat -r" shows:

Routing tables
Destination      Gateway            Flags  Refcnt Use       Interface
Netmasks:
(root node)
(0)0                                         
(0)0 ff00 0                                  
(0)0 ffff ff00 0                             
(root node)

Route Tree for Protocol Family 2:
(root node)
default          137.132.86.1       UG         17  1812639  en1
loopback         localhost          U           5  5415096  lo0
137.132.86       ibmunx             U         608 17124843  en1
137.132.87       ibmunx             U          64  2829747  en0
decfddi          ibmfddi            UH          0      525  fi0
(root node)

Route Tree for Protocol Family 6:
(root node)
(root node)