Implementation of RIPE-181++

  > Jessica Yu <jyy at merit.edu> writes:
  > >It should also be noted there is no direct relationship between  the
  > >cost used in as-in and the preference used in interas-in.
  > 
  > Actually, the cost in as-in and the preference in interas-in need to be
  > comparable.  

No.

  > aut-num: AS1
  > as-in: from AS100 1 accept AS100        
  > interas-in: from AS100 L1 R1 (pref=1) accept {a,b,c}
  > interas-in: from AS100 L1 R1 (pref=2) accept {x,y,z}
  > interas-in: from AS100 L2 R2 (pref=1) accept {x,y,z} 
  > interas-in: from AS100 L2 R2 (pref=2) accept {a,b,c}
  > 
  > If people do explicitly list their interas-in policy, then there is no
  > problem.  However, if people do not explicitly list them as the current
  > version allows, then we will have a problem if the cost and pref is not
  > comparable. 
  >  
  > aut-num: AS1
  > as-in: from AS100 1 accept AS100
  > interas-in: from AS100 L1 R1 (pref=1) accept {a,b,c}
  > interas-in: from AS100 L2 R2 (pref=1) accept {x,y,z}
  > 
  > This implies that
  > 
  > interas-in: from AS100 L1 R1 (pref=1) accept {x,y,z}
  > interas-in: from AS100 L2 R2 (pref=1) accept {a,b,c}

It does not imply that. 
According to the wording it implies:

interas-in: from AS100 L1 R1 (pref=some) accept AS100
interas-in: from AS100 L2 R2 (pref=some) accept AS100

Where "some" is not explicitly defined by the text but implicitly
greater than all preferences mentioned in interas-in attributes.

  > This is incorrect policy.

This is what was intended.

  > So for this example, either we advice people the be carefully put their
  > cost and pref that means they are not uncomparable, or have to have them
  > explicitly list the interas policy which needs a change to the current
  > text.

For this example I would indeed advise people to say things explicitly.

The implicit rules are intended for cases specifying exceptions like

aut-num: AS1
as-in: from AS100 1 accept AS1 AS2 AS3 AS4 AS5 AS6 AS7 
as-in: from AS100 1 accept AS31 AS32 AS33 AS34 AS35 AS36 AS37 
as-in: from AS100 1 accept AS61 AS62 AS63 AS64 AS65 AS66 AS67 
interas-in: from AS100 L1 R1 (pref=1) accept AS34

In such cases repeating all the AS numbers just adds noise, whereas the
short form makes it immediatly obvious what the local policy deviation
is.  Note that in practise this will often be true for your example case
as well. 

Daniel



-------- Logged at  Tue Oct 4 22:13:38 MET 1994  ---------