[db-wg] Slash notation

Shane,
sounds good to me !!
Thanx
Dave Trickett
BTnet

-----Original Message-----
From: Shane Kerr [mailto:shane at ripe.net]
Sent: 21 May 2003 16:56
To: IPMASTER G
Cc: db-wg at ripe.net
Subject: Re: [db-wg] Slash notation


On 2003-05-21 16:26:43 +0100, ipmaster at bt.com wrote:
> Hi
> 
> Quick question:-)
> We used to be able to update (via email) the Database with new
> inetnums using slash notation. Since the introduction of RPSL, this
> facility has been lost, would it be possible to re-introduce it?
> I can see the benefits of using the long hand version if I am
> updating with a /27 and a /28, such as (*.*.*.64 - *.*.*.111).
> But for Inetnums that fall on the bit boundary would not make sense
> to enable the slash?
> If I update a route object I can still use the slash notation.

Short answer:

When version 3 of the Database software was designed, one of the
principles used was to not change user data as it was submitted.  This
included the transformation you defined.

The easiest solution would be to convert the CIDR to ranges, as you
suggest, so:

inetnum: 193.0.0.0/20

Would become:

***Warning: inetnum '193.0.0.0/20' converted to '193.0.0.0 - 193.0.7.255'

inetnum: 193.0.0.0 - 193.0.7.255
   .
   .
   .

If this makes sense, we'll include this change shortly.



Explaination (for the curious):

The reason that these types of modifications were avoided in the
original design is because RPSL allows a number of formats that can
make the changes difficult.  For example:

inetnum:
   # this
+# is a valid
     # inetnum attribute
                                193.0.0.0 
+                                -
        # heck, you can even put a comment here
 193.0.7.255
+ # and at the end too


Modifying this kind of attribute can be problematic, because the
value is split across many lines, and has comments in the middle.

However, with your suggestion it would be possible to do something
like converting:

inetnum:
   # this
+# is a valid
     # inetnum attribute
                                193.0.0.0/21
+ # but still parsable!

Into the following:

inetnum:
   # this
+# is a valid
     # inetnum attribute
                                193.0.0.0 - 193.0.7.255
+ # but still parsable!


Since the CIDR-notation is "atomic", we don't have to worry about
values split across lines or with comments inside.

Note that comments and split lines in the primary attributes are very,
very rare, but it is technically possible for any user that wishes to
do so.

-- 
Shane Kerr
RIPE NCC