do ISPs keep track of end-user IP changes within thier network?

Sam Moats sam at
Thu Dec 12 11:34:26 UTC 2013

I'm not sure about the current state of the industry it's been a while 
since I was responsible for an access network. In the past we would keep 
radius logs for about 4 months, these would include the username,IP 
address and yes (to date myself) the caller id of the customer at the 

Sam Moats

On 2013-12-12 03:49, Ray Wong wrote:
> been a while, but seems like lately it's more a question of how long. 
> ISPs
> can be in position where they need to, but as things have 
> consolidated,
> seems like they'd really like to forget it as soon as they can. If 
> you've
> got a specific case in mind, likely best to find a direct contact and 
> get a
> response about policy, even if it has to be off-record. The big ones 
> (like
> one I likely shouldn't mention by name unless they do as I don't work 
> for
> them) definitely do, at least long enough to handle DMCA requests and 
> other
> legal obligations.
> -R>
> On Wed, Dec 11, 2013 at 9:36 PM, Mikael Abrahamsson 
> <swmike at>wrote:
>> On Wed, 11 Dec 2013, Carlos Kamtha wrote:
>>  just a general curiousity question. it's been a long time since ive
>>> worked at an ISP.
>>> back then it was non-expiring DHCP leases and in some cases static 
>>> IP for
>>> all.. (yes it was long ago..)
>>> Any feedback would be greatly appreciated..
>> Yes, it's very common to keep track of what user account/line had 
>> what IP
>> at what time.
>> --
>> Mikael Abrahamsson    email: swmike at

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