When a change is done to the Subnet Mask, if you have only one default route (gateway),
you will need to go into CFGTCP, option 2 and change the subnet mask on the IP address.
It could take a while before the new IP
addresses are known to the other machines so you may need to flush the DNS cache…
To flush the DNS cache on the iSeries, enter the
CHGTCPDMN command without any parameters.
To do this on a Windows PC/Server :
on a Command Prompt :
Hope this helps…
This change impacts lot of things – printing & client terminal access, etc. Be sure that routes are properly setup to the new subnet so communications will continue with the new subnet mask.
If you are responsible for the AS/400, the default route subnet mask should be set as noted above by Labnuke99. It’s likely that that is the only change needed.
If you are responsible for PCs, they should already be set up for DHCP and DNS and should take care of themselves. Printers shouldn’t care about subnet masks. You’d already know that if PC communications was your responsibility, so you can almost certainly ignore them.
In short, the single simple change is probably all you should do.
If problems arise, post details of the problems in a new question. Be sure to include any related error message identifiers. Problems would come from incorrect or inappropriate TCP/IP configuration that can’t be anticipated here. A new question can focus on changes that possibly should be made.