Conference 7.286::fddi

1735.0. "DEC300 with DEFTA-UA DECnet/OSI problem" by KARCS1::WEBER (Klaus Weber) Wed Jul 05 1995 09:25

Hello,

we have a very strange problem. Involved are two DEC3000 M600 with
DEFTA-UA FDDI Interfaces.

Configuration:	Dual FDDI ring as Backbone.
		The DEC3000 Systems are the only nodes on the ring.
		They're connected trough a DECrepeater 900MX/UTP.
		Two DECnis 600 on two seperate (bridged) Ethernet segments.
		The DECnis are operating as L2 router with RVR protocol. 
		One of them is the designated router.
		Serveral Phase IV and Phase V endsystems on different 
		(bridged) Ethernet segments. 

Versions: 	OSF/1 V3.2 (Rev. 214)
	  	Firmware rev. 6.0
	  	fta0 Firmware rev. 2.44
	  	DECnet/OSI 3.0-0 (Rev. 11.27)
	  
	 	DECnis 600 V2.1-1

Problem: 
Communication problem between the DEC3000 DECnet/OSI ES and all Phase IV 
Endnodes on the LAN (Ethernet). As soon as we configure (DECnet/OSI) the fta0 
device with Phase IV address enabled (AA-00-04-00-XX-XX) communication 
to any Phase IV endnode is not possible, communication to Phase IV routers, 
Phase V routers and to other Phase V endsystems works.
If we configure the fta0 interface to use its hardw. address 
(08-00-2b-xx-xx-xx) instead any communication is ok. We did this by
enabling both interfaces ln0 and fta0 where ln0 as the first one gets
the AA-00-04-00-XX-XX address. Ln0 is phys. not connected to the LAN.
The problem is only releated to DECnet. All the other protocols (TCP/IP,LAT,
NETBUI) are working properly.
Putting one of the two DEC3000 together with a Phase IV VAX in an unused
DECnet Area, just to exlude all the routing stuff, did'nt solve our problem.
Switching the routing mode from Integrated to Segregated did'nt help.
If we going to use the Ethernet inteface everything is OK.

IRIS and CTF traces showing us, that no DECnet packets are ariving at the 
routing layer of the DEC3000. On the LAN, from the Phase IV system point 
of view, we get no response from the DEC3000.


Questions: 
	-Is there anybody else with the sam kink of problem ?
	-Is there any explanation of this behavior ?
	-Is there any solution or did I something wrong ?

Thanks for any help or pointers ,
Klaus

Hi,

the problem is solved by changing the type of the fddi
routing circuit from fddi to csma-cd.

Klaus