gwadminservice 2014

I am upgrading a cluster on ncs gw 2012 to 2014. I installed first node and
upgraded both primary domain and gwia domain on the same server. Everything
worked great. I than went through the steps for the second node of the
cluster. The strange part is that the first node actually set the admin
service to run against the primary domain address, For some reason the
second node upgraded put the admin service on the ip for the secondary
domain. 2 questions.

1. How to get the second node to have the admin service running on the
primary domain address?

2. Is it necessary to have multiple admin services running to address when
the 2 domains are running on different nodes? I would think not but thought
I would check.