OpenView Network Node Manager: Designing and Implementing an Enterprise Solution

Router Access Control Lists and NNM

Since routers must operate perfectly at all times, network managers do everything they can to prevent unauthorized access. One feature that’s always used is the access control list (ACL), also called simply the access list. This list is a sequence of one-line entries in the router configuration file that can limit access to certain services by certain devices or a range of IP addresses.

Since NNM uses SNMP, it follows that routers should be configured to allow the NNM systems access to the SNMP service on port 161. Access can be further restricted to a certain portion of the MIB (depending on the vendor and the router O/S version). For example, an external access router with a huge routing table will suffer ...