If you don't purchase a static IP from your ISP, your ISP has no obligation to keep permanent the one it leases to you via DHCP.  So you should always treat your IP changing as a possibility regardless of what you or others have observed.  Your IP changing is normal if you do not have a static IP from your ISP.

There are "dynamic DNS" services - Dyn (formerly Dyndns) and No-IP being two of them - that will let you create an account, obtain a DNS hostname, and then run an "update client" somewhere on your internal network.  The update client will periodically check your external IP and report changes to the service.  So then this DNS will resolve to your public IP.

Dyn used to be free, No-IP still is AFAIK (this may have changed).

You'll still need to make sure NAT is set up correctly if you want external requests to reach a specific system inside your network.  You also cannot use this DNS to reach hosts from inside to inside your network unless you run your own DNS server and resolve LAN-local names yourself.

How often will my Comcast IP address change?
I've been using Core Plot for my iPhone application and have been displaying a scatter plot. I was wondering if upon appearance of the view, there is anyway to have the scatter plot start off as just a horizontal line with all y-values the same, and then have some sort of 0.5 second, for example, animation that slowly moves each data point up or down to its appropriate position?? Or, more generally, if the scatter plot can be animated in any way using core plot? Thank you all in advance.
