AS path extensions

General comments:

I think it would be better not to let this be defined by a cisco 
manual. It is also more than just the regex bit. I would briefly describe 
it as something like "AS paths are coded textually thus ... and AS Path regular
expressions use POSIX 1003.2 section 2.8 regular expressions to match them.
The interesting stuff here is AS-sets etc ......

The "Interaction Between ...." section is confusing.
Semantically what I would like to see:

One can use only orignal or only extended attributes for a given peer AS.
The semantics in this case are clear. 

Once can also use both kinds of attributes for a given peer AS.
In this case care should be taken that the expressions are as 
equivalent as possible and certainly not contradictory.
[This is the maximum one can ask and mucho clearer than what you have].

At this point in timew it is strongly recommended to provide original 
attributes for the benefit of tools that do not understand extended 
attributes yet.

Example 4 contradicts your text in the Interaction para.
The as paths are not anchored either ?!?

Refer to ripe-181 when cautioning about changing and complex topologies.
It explains it all.

Daniel







-------- Logged at  Mon Mar 6 22:51:11 MET 1995  ---------