How does the reference host function work and how should it be implemented?

Issue

How does the reference host function work and how should it be implemented?

Product Line

TAC I/NET

Environment

I/NET Site

Cause

How does the reference host function work and how should it be implemented?

Resolution

Reference host is a widely misunderstood concept. Proper usage is as follows. Pick one computer or NPR to serve as reference host. Enter its TCP\IP address in the reference host field of all other hosts and NPRs. Do not enter anything in the reference host field in the configuration of the reference host itself. The reference hosts job is to insure that all hosts and NPRs have a complete list of all other hosts and NPRs that have referenced it as the reference host.

After the initial setup of the site, all hosts/NPRs have IP routing info for all other hosts/NPRs so that even if the ref. host is off, the remaining hosts/NPRs can still connect to each other.

There have been problems caused by reference hosts referencing themselves as reference hosts.

Another item to be aware of is where 2 or more reference hosts reference each other and someone connects temporarily with or without a shared link. Or maybe some one changes a link designation on an NPR. This "infects" all hosts with the erroneous link or address. In an attempt to clear it out, a customer made new configurations for each host but continued with the same ref host scheme so as he brought up each host with its new config, it received the infected IP list from the other hosts. If NPRs are used, the cleanup is even more complex.

Another problem was caused as a customer entered the address of each NPR into the reference host designations in his computer. He did not enter anything for reference hosts in the NPR configs. Therefore, they had no routing table for use in passing global point data between them. Each NPR only knew about itself and the host that referenced it, not each other.