I have been having the following problem with monitoring my remote VPN sites that use Cisco Pix, ASA, and 877 units. When I initially add one of the nodes to NPM using SNMP v1, it discovers the node and both the inside and outside interfaces just fine. It also discovers the CPU and Memory Use just fine. After a while, the interfaces eventually go to and "unknown" status as does the CPU and Memory Utilization. At first I thought it was something with the PIX codes we are running on the remote L2L vpn devices (various releases 6.3(4), 6.3(5), 7.2(2)) but then I installed a Cisco 877 configured as a crypto endpoint for another location and the problem happened with that site as well. Then I thought it was with the version/set up of NPM I inherited so I built a new server from scratch with all new discoveries running NPM 8.5.1 sp 3 and the problem still remains. If NPM is stopped and restarted, or if I run a new baseline, it rediscovers everything just fine, and a little while later, interfaces start to "disappear" on my VPN sites. Has anyone else encountered this odd behavior?