Conference 7.286::fddi

1810.0. "FDDI-to-Ethernet failover" by ALOS01::SCHAFFER () Tue Sep 19 1995 14:13

  I am working at a large customer site which has recently integrated an
  FDDI backbone into an existing ethernet LAN. They are running VMS
  v5.5-2 and 6.1 with DECnet phase IV on multiple systems and clusters.
  In addition, TCP/IP and LAT protocols are running on the network. The
  heart of the FDDI network is a  Digital GIGASWITCH which connects each
  large VAX and AXP server system via a single fiber cable (SAS). The
  customer wants to provide automatic failover to Ethernet for each
  system in the event of an FDDI failure. They already have two command
  procedures written and tested that will shutdown the fiber circuit and
  startup the Ethernet circuit and vice versa. (They are listed below.) 

  What I need is a procedure to determine when the FDDI link is down.
  What would be the best way to tell if the FDDI circuit is down or
  having problems? Check circuit counters via NCP or ERRLOG? Is there
  already a product or routine within a product that could do this, such
  as POLYCENTER System Watchdog, ...?

  Note 5311 in the DECnet-VAX conference tells me that others are doing
  this. I have cross-posted this note in the DECnet-VAX conference. Any
  help would be greatly appreciated.

  Thanks,

  -Tom.

----------------------------------- Attachment --------------------------------
--------------------------------------
Procedure to switch from FDDI to E-net 
--------------------------------------
$ SET NOON
$ lcp :=$latcp
$ ncp :==$ncp
$ node = f$getsyi("nodename")
$!
$ IF node .EQS. "OMRDD7" .or. "OMRDD8" .or. "OMRTB1"  then
$!
$!    !Disable LAT, DECNET, and TCP/IP on FDDI
$      ucx set nointerface ff0
$      lcp set link/state=off lat$link
$      ncp set cir mfa-0 state off
$      ncp set line mfa-0 state off
$
$!    !Enable LAT, DECNET, AND TCP/IP on Ethernet
$      ncp set line mna-0 state on
$      ncp set cir mna-0 state on
$      lcp create link/dev=exa0:/state=on lat$link1
$      ucx set interface xe0/host='node'
$ endif
$!
$ exit

--------------------------------------
Procedure to switch from E-net to FDDI 
--------------------------------------
$ SET NOON
$ lcp :=$latcp
$ ncp :==$ncp
$ node = f$getsyi("nodename")
$!
$ IF node .EQS. "OMRDD7" .or. "OMRDD8" .or. "OMRTB1"  then
$!
$!    !Disable LAT, DECNET, and TCP/IP on Ethernet
$      ucx set nointerface xe0
$      lcp set link/state=off lat$link1
$      ncp set cir mna-0 state off
$      ncp set line mna-0 state off
$
$!    !Enable LAT, DECNET, AND TCP/IP on FDDI
$      ncp set line mfa-0 state on
$      ncp set cir mfa-0 state on
$      lcp set link/state=on lat$link
$      ucx set interface ff0/host='node'
$ endif
$!
$ exit