[comp.dcom.sys.cisco] AppleTalk and 8.2

pjones@cisco.com (Patrick Jones) (06/21/91)

The following is a response to the many calls Cisco received concerning
the gateway software release version 8.2(4) and AppleTalk routing.  The
calls were generated by a concerned customer who experienced problems on
their network.  The issues were quickly resolved with the details given
below.

Please, if any site experiences any problems with our products
regarding AppleTalk or any other protocol, give us a call at the 
Technical Assistance Center: 1-800-553-2447.  If you prefer e-mail,
then a message to "customer-service@cisco.com" may be used.

Patrick Jones
Technical Support Manager
Cisco Customer Engineering

   Problems were recently reported with AppleTalk in version 8.2(4) by
   University of Indiana.  I thought I would explain the problem they
   found.  The fix for this problem has been submitted for 8.2(5).  We
   do not consider this to be a critical failure and we continue to believe
   that 8.2(4) is the best version for all AppleTalk sites.

   The routing table data structure, replaced in 8.2(4), fails to check
   for a reversed cable range (ie 98-2) when processing tuples in an RTMP
   data packet.  This is not a legal tuple and is never normally generated.
   However, some routers may not check for this error during configuration 
   and the router could then send such a poison packet.  Certain combinations
   of illegal cable ranges can violate the assumuption that routing keys are
   always positive and corrupt the routing data structure.  This results in
   a crash and immediate restarting of the router.

   During the 3+ months of 8.2(4) beta testing, which was conducted at
   eight major sites (with a combined total of more than 2200 nets), this
   problem was not encountered.  We do not believe that there is a high
   probability that sites will encounter this problem.  

   -dle

   David Edwards
   AppleTalk Engineer
   Cisco Engineering