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[jw AT plews.org.uk]

On Friday, 22 March 2019 12:30:45 GMT overthefalls AT opengroupware.ch wrote:
> 
> That isn't necessarily true, in fact I *think* it's fairly unlikely. In
> my experience and from what I've read, most ISP's don't really do
> dynamic IP's for individuals any more. My IP doesn't change unless my
> router MAC changes, or when I change hardware. I think static IP's have
> a lot of benefits for surveillance and consumer tracking (unfortunately)
> that have made them much more common. Sucks for privacy, but IF that is
> the case for Craig, dynamic IP's aren't a hinderance.

In a typical DHCP pool if you keep renewing before your lease expires then 
you'll keep getting the same address. Since DOCISS type connections use DHCP 
this is probably why you observe an infrequently changing address.

If the ISP reboots _their_ router, and leases are not kept on non volatile 
storage then you'll get another random address. Some DHCP servers hash your 
MAC instead of sequential or random assignment too.

since PPP for ADSL involves a user name anyway it's easy to keep consistent 
addresses but often it'll be a pool too, so in general your less likely to 
get 
a repeat IP unless it's set statically for you, since there isn't the same 
concept of a lease in PPP and there are no broadcast domains.

Some DHCP clients will request their previous address, if the lease has 
expired but not yet reassigned, and the DHCP server can honor the request you 
get the same address again.

With the cheap option ADSL service at my house, not only to i get different 
addresses, but also different IP blocks with different registered geo 
locations.

I bet there is also another level of logging that probably maps IDs we can't 
even see from the customer side :) deep in the DSLAM side of things, 
especially on newer equipment.

For spying, my ISP must keep a log of DHCP leases or PPP sessions and IP 
addresses and times linked to your ISP account. If they could not keep such 
logs then a fixed IP via PPP would keep them legal too. From my limited 
experience it's very much like if you have security camera's overlooking 
public places and it's broken when the police need them... uh-oh