static or dynamic ips

I run this site and I approve access for a section of the site for people. I only want to approve static ips. If i have a bunch of IPs how do I find out if they are static or not? I can do the remaining parts but there is probably some function in the socket library or something that lets me script the part to find if the users are using static or dynamic IP.

thanks !

Php开发者_JS百科/Js would work too.

There is no way to inherently tell if an IP address is static or dynamically assigned. Based on the hostname that the IPs resolve to, you could probably make a guess as to whether they are static or not, but there is nothing definitive to facilitate this.

You could use the socket module to resolve the IPs to hostnames and flag them as "static" or "dynamic" based on some kind of "best guess" algorithm, but it would be only that: a best guess.

Here is an example using a random Verizon FiOS IP address. This assumes that any IP starting with "pool" is dynamically assigned.

>>> hostname = socket.gethostbyaddr('71.243.222.111')[0]
>>> if 'pool' in hostname: 
...     print hostname, 'is dynamic'
... 
pool-71-243-222-111.lsanca.fios.verizon.net is dynamic

You're going to have a very tough time determining all of the various naming conventions and this would in no way be a complete solution.

You might want to ask yourself what kind of problem you're trying to solve first, and whether filtering access by IP address is providing the kind of verification you need.

I'd use a pragmatic solution: New accounts have a trial phase of a few days. After that they can only log in from the same IP used to sign up. If they still have that same IP it's most likely static.

Well, you don't have a problem, do you? If they ask for access from IP X, you give them access from IP X. If it turns out that it was dynamic and they switch, they no longer have access. In practice, no access from dynamic IPs :)

Seriously though, the authority on IP assignment type is the host from which the user is accessing. Thus, you need to ask the user what it says in his/her config.