Interesting object in the RIPE database

On Tue, Jul 06, 1999 at 06:24:30PM +0200, Niels Bakker wrote:
> Clive Galway (the creator of this object) told me after I contacted him
> that he had entered the following information into the template:
> 
> 195.59.213.0 - 213.127 instead of
> 195.59.213.0 - 195.59.213.127
> 
> He added, "funny that it dont complain though" - I agree wholeheartedly
> with him here. :)  A check for the number of dots in the inetnum: line
> should be quite easy, and similar to this:
>
> [snip perl]

>From BSD's inet(3):

  INTERNET ADDRESSES
     Values specified using the `.' notation take one of the following forms:

           a.b.c.d
           a.b.c
           a.b
           a

     When four parts are specified, each is interpreted as a byte of data and
     assigned, from left to right, to the four bytes of an Internet address.
     Note that when an Internet address is viewed as a 32-bit integer quantity
     on the VAX the bytes referred to above appear as ``d.c.b.a''. That is,
     VAX bytes are ordered from right to left.

     When a three part address is specified, the last part is interpreted as a
     16-bit quantity and placed in the right-most two bytes of the network ad-
     dress.  This makes the three part address format convenient for specify-
     ing Class B network addresses as ``128.net.host''.

     When a two part address is supplied, the last part is interpreted as a
     24-bit quantity and placed in the right most three bytes of the network
     address.  This makes the two part address format convenient for specify-
     ing Class A network addresses as ``net.host''.

     When only one part is given, the value is stored directly in the network
     address without any byte rearrangement.
     All numbers supplied as ``parts'' in a `.' notation may be decimal, oc-
     tal, or hexadecimal, as specified in the C language (i.e., a leading 0x
     or 0X implies hexadecimal; otherwise, a leading 0 implies octal; other-
     wise, the number is interpreted as decimal).

I haven't looked for an RFC (STD) specifying the official interpretation
of IPv4 addresses with less than four parts, but it looks like the RIPE
interpretation is at odds with the BSD one at least (in which 213.127 would
be the same address as 213.0.0.127).

> I believe there is a sub to check whether something is a valid IP address
> but can't find it offhand in my (by now pretty dated) copy of the RIPE
> database software...

Again, inet_aton(3) would do it...


Joe

-- 
Joe Abley <jabley at clear.co.nz>      Tel +64 9 912-4065, Fax +64 9 912-5008
Te Kaihoahoa Kawei, CLEAR Communications Ltd      http://www.clear.net.nz/