queries on rmon

ricky

Hi All,

    I saw in IEWB, wheneven the question ask to "log an event when the interface input octets (ifEntry.10.1) value reaches 45000 per minute", the solution uses "rmon alarm 1 ifEntry.10.1 60 delta rising-threshold 4500..."  The thing that confuses me is the "delta" key word used instead of "absolute"..  can anyone share some explaination on this?  It seems to me that the interface octet polled by SNMP is definately an "absolute" value and the question ask "to log an event when the interface input octets value reaches xxx"?

Cheers,
Ricky

NTllect

delta measurement uses whenever we need to sample objects per interval(a minute in this case)

absolute keyword means to trigger trap whenever object being monitored reaches whatever threshold. It may be one minute since startup, or few days. CPU monitoring usually use this kind of monitoring.

http://www.cisco.com/en/US/docs/ios/netmgmt/command/reference/nm_09.html#wp1012413

 

ricky

hmm.. meaning is i configure " rmon alarm 1 ifEntry.10.1 60 delta rising-threshold 45000", and supposed the if octect 1 minutes ago is 100kbye/s, then the alarm will only trigger when the current interface octet count is 145000 kbyte/s? (delta = 145000-100000)  That is not quite what the question ask right?