I am in the process of changing my secondary name server IP address.

Originally I had the following Name Servers:

ns.domain.com ==> 000.000.000.001
ns2.domain.com ==> 000.000.000.002

I am changing to:
ns2.domain.com ==> 000.000.000.003

I updated it with my registrar and all of the domains changed the IP address for the secondary EXCEPT for the ones still registered with Network Solutions.

Do I have to go back and change every domain record to update the nameservers??? or is it a propagation thing? It has been a couple of days already.

I'm not sure, but I don't think you have to update this with the registrar, as long as the hostname of the nameserver doesn't change (the ns2.domain.com part).

They generally ask for an IP, but I don't think they need the IP address. Once their system realizes that the name server resolves to a different IP, it should update its records. Oddly enough, Network Solutions database always seems to be the last one to reflect DNS changes...

At any rate, I think that just updating the actual HOST record for the name server should be all that is necessary. Domains which point to that name server shouldn't need to be changed. But again I am not 100% on this...

You will never get NSI to update their records. Everything will work fine though even if they have the wrong IP.

I have also changed the IP's of my nameservers but Network Solutions doesn't seem to be updating their records for me either. Whether it works or not, I will never know for certain...