We are currently working on migrating a lot of new machines to our network, and my job this morning was to setup all of the IP Addresses. I worked on this all morning, and when I got back tonight I was informed that they had all been setup incorrectly, and had to be removed and re-added. I am quite confused as I have been setting up IP's on machines for a long time and I am curious as to what the issue is.

Just taking into account this example...

72.26.196.160/29 255.255.255.248

A /29 block is 5 usable IP's. With the script I wrote and used, the IP Addresses .162 - .166 were added to the NIC. I can't remember now what the name for .161 was, but isn't it the broadcast address or something which isn't assigned to the NIC when adding additional IP Blocks?

I am curious as to where my logic is failing me. Not to mention even if .161 was to be added, there is no reason why all of the IPs would have to be removed, as .161 could just be added in addition to these.