OpenView Network Node Manager: Designing and Implementing an Enterprise Solution

DNS Problems

One area of grief is DNS, badly implemented name servers, and security features in DNS. For example, consider a router with a large number of primary and secondary IP addresses. Suppose that a client such as NNM requests the name for 1.1.1.1 (using the standard resolver). As a security precaution, the resolver insists that the resulting name should map back to the same IP address. But some DNS name servers truncate long lists of IP addresses (because they don’t revert to TCP for replies longer than 512 bytes), then the original lookup request returns no name. This will confound NNM because it can’t map the IP address to a name, and thus can’t use the proper community string to communicate with it.

Another example of DNS grief is ...