Once initially defined engineid should be static, a lot of SNMP polling applications use engineid as device identifier. Consistency and uniqueness are both important. Some polling system will not allow you to add another snmp device If engineid is a duplicate.
Network devices usually derive engineid from lowest "numbered" interface. Unfortunately you can manually set them, this is bad when someone creates a configuration base template which has engineid defined, then you end up with 100's of network devices with the same engineid. I've spent quite a bit of time cleaning up from the mess this created. diana
