Not so long ago my routers WAN IP address was reasonably static, it would generally stay the same for weeks at a time, usually only changing on a router reboot, however recently this has changed, and not just different addresses in the same scope but vastly different scopes.  In the last week I have had addresses from:

• 111.69.227.x
• 123.255.26.x
• 163.47.220.x

Sometimes my address is shifting daily.

I have a fundamental issue with paying $10 for a "static" address as this seems like a huge rip off for what is essentially a one off reservation in a DHCP range somewhere so I use a dynamic DNS service.  

So from work I have a connection running to home and all is fine and suddenly it disconnects, so I flush my DNS and do a refresh pick up the new IP and off we go again, annoying but not end of the world.

Now where it really becomes an issue is firewall rules.  I have some stuff from other locations that I am trying to lock down so allow connections from specific IP ranges, with the above carry on this has become pretty much impossible (OK lets allow connections from 111.x.x.x to 163.x.x.x, that nearly a third of the whole flippin internet!).

I thought I would contact my ISP as in the past I have found them to have really good service (until they were purchased by a larger telco that is), I was assuming they were doing some changes and wanted to know if things were going to settle down.

As suspected the poor first level "have you rebooted your router" support guy didn't have a clue so he tried to sell me a "static" address (I used to have a real static address once in the good old days of KCBBS, that is one you manually enter in on your router WAN interface).  I got his to escalate for more information.

I got an email response from them later that evening:

Per our phone call I have spoken with NOC our network tech team.   They have advised me that they reserve the right to make alterations to IP addresses dynamically on ranges at their discretion.   If you are still concerned we have as per our conversation the option of a static IP.   That's a pretty sh*tty response really.  Yes I understand and accept they have the right to make alterations, I was not challenging that, just wanting to know why the big changes and the frequency.   Stuck in a contract with these guys for another year, decided to move on after that as they put my charges up twice now whilst in contract, and now they are offering the general public a much better deal than the one I am locked into which is pretty darn rude.   Ah the downfall of a once good ISP.   Rant.end() };