ipv6 validation

[jiri.juranek]

Hello,
is there any common function for validation if string contains valid ip
address(both ipv4 and ipv6)? Or does sb wrote some regular expression
for this?
thanks
J

 

[Roy Smith]

Hello,
is there any common function for validation if string contains valid ip
address(both ipv4 and ipv6)? Or does sb wrote some regular expression
for this?
thanks
J

Look at socket.inet_pton(). First check to make sure ipv6 is supported on
your platform, then pass your string to inet_pton() inside of a try block
to catch socket.error. It would have been nicer is a more specific
exception was thrown, but this seems to work. For example:
Traceback (most recent call last):

Be aware that IPv6 support is messy on Windows. For example, if you're
running Win 2003 (or XP, I would guess), the OS does support IPv6 (and thus
socket.has_ipv6 will probably bet set to True) but the IPv6 libraries don't
actually get loaded until you configure an IPv6 address on some interface.
This means things like inet_pton() will fail, which is truly bletcherous
and evil.

Writing a regex to recognize valid IPv6 presentation strings is not
trivial. Keep in mind that you're allowed exactly 0 or 1 "::" occurrances,
and things like "ffff::192.168.11.1" are legal (I don't remember if I got
the semantics right there, but the syntax is legal).

 

[jiri.juranek]

thanks a lot for this solution.
Next thing: how may i find out that that address is multicast one? is
there some easy possibility or i have to use regex now?

thanks

 

[Christos Georgiou]

thanks a lot for this solution.
Next thing: how may i find out that that address is multicast one? is
there some easy possibility or i have to use regex now?

To quote a Google reply:

"IPv6 multicast addresses are distinguished from unicast addresses by the
value of the high-order octet of the addresses: a value of 0xFF (binary
11111111) identifies an address as a multicast address; any other value
identifies an address as a unicast address."