swatt@noc.net.yale.edu (Alan S. Watt) (05/29/90)
I have noticed several times now while monitoring a cisco gateway that certain SNMP interface variables appear to be reset. At first I thought this was just my problem in handling 32-bit integer overflow conditions, but as the following log shows, this is not the case: ---------------------------------------------------------------------- Thu May 24 18:54:32 1990 sysUpTime_0 0x14ce0099 349044889 Thu May 24 18:54:32 1990 ifInOctets_1 0xc56f39 12939065 Thu May 24 18:54:32 1990 ifOutOctets_1 0x49682acd 1231563469 Thu May 24 19:09:36 1990 sysUpTime_0 0x14cf61d8 349135320 Thu May 24 19:09:36 1990 ifInOctets_1 0xebcef1 15453937 Thu May 24 19:09:36 1990 ifOutOctets_1 0x49795036 1232687158 inOctets = 2514872 outOctets = 1123689 Thu May 24 19:24:42 1990 sysUpTime_0 0x14d0c3bb 349225915 Thu May 24 19:24:42 1990 ifInOctets_1 0x15b471 1422449 Thu May 24 19:24:42 1990 ifOutOctets_1 0x4982cb27 1233308455 inOctets = -15311688 outOctets = 621297 Thu May 24 19:39:47 1990 sysUpTime_0 0x14d2254b 349316427 Thu May 24 19:39:47 1990 ifInOctets_1 0x3a5fdd 3825629 Thu May 24 19:39:47 1990 ifOutOctets_1 0x499e336e 1235104622 inOctets = 2403180 outOctets = 796167 ---------------------------------------------------------------------- The polling is done at 15-minute intervals. Subsequent entries continue to add reasonable increments to the "inOctets" variable. The polling process is killed and restarted every night at 2AM, so if the polling program itself was getting confused, this would show up when the log files rolled over, but it doesn't. This is no write-access defined for this router, so the counters cannot be modified by SNMP. It is running 7.1(17) (AGS/2). Anybody know any problems which could account for this? - Alan S. Watt High Speed Networking, Yale University Computing and Information Systems Box 2112 Yale Station New Haven, CT 06520-2112 (203) 432-6600 X394 Watt-Alan@Yale.Edu
satz@cisco.com (Greg Satz) (05/30/90)
There are known ASN.1 integer encoding bugs in the older 7.1 software releases. These bugs make the numbers appear to go backwards. 8.0 and beyond have these problems corrected. Drop a note to customer-service@cisco.com for information on newer bits. Greg