Conference 7.286::fddi

1255.0. "Connectivity problem via DECbridge 610 ?" by CRONIC::ANTROBUS (And we thank you for your support.) Tue Mar 01 1994 19:26

    
    I currently support an OpenVMS VAXcluster configured, in part, on a fddi 
    ring, in preparation for adding an AXP boot node and several AXP 
    satellites.   Presently, the cluster consists of two VAX boot nodes,
    and twenty-five VAX satellites.  Each of the VAX boot nodes are 
    configured with dual network adapters, one fddi and one ethernet.  
    
    The fddi devices on the VAX boot nodes are connected directly to the ring,
    and are currently running LAVC, TCP/IP and LAT.  The ethernet devices
    on the boot nodes are connected to a segment/port behind a DECbridge
    610 and are running DECnet.  All VAX workstations are also connected
    to this DECbridge 610.
    
    Recently, we have discovered a problem with one of the VAX boot nodes
    trying to establish a DECnet connection to one of the nodes on the
    ring.  Investigating the problem revealed that the DECbridge is
    confused and unable to pass the connect information through.  In
    the past, we saw this behavior when the DECnet protocol was swapped
    quickly between fddi and ethernet.  However, in this case, the
    DECnet protocol has remained on the ethernet for months now.  Can
    anyone offer any suggestions as to what this problem could be ?
    
    
    

Make sure that none of the protocols using the FDDI adapters are using the
"DECnet address" to do so.  LAT and possibly LAVC can be told to do that, 
which eliminates the startup ordering problem on Ethernet.  But on FDDI this
is neither necessary nor useful.  (In fact, it should not be an option for
FDDI, but it may well be available due to the use of common code.)

	paul

    
    In looking at the output of a "SDA SHOW LAN/FULL" on each boot node,
    I see that the ethernet adapter with LAT, FXA2, shows a physical
    address which is in fact the "DECnet address" (AA-00-04-00-xx-xx)
    associated with the ethernet adapter, EXA3.  Could this be causing 
    the problem ?