Manish Vora | 22 Jan 10:42

Question on draft-ietf-idr-rfc4893bis-01.txt

I have a couple of questions on the error handling procedures in draft-ietf-idr-rfc4893bis-01.txt.

(1) Some snippets from Section 6, on Error Handling

   The general guidelines presented in [ATTR-ERROR] apply to the error
   handling of the AS4_PATH and AS4_AGGREGATOR attributes introduced in
   this document.

   ...

   A NEW BGP speaker that receives a malformed AS4_PATH attribute in an
   UPDATE message from an OLD BGP speaker MUST discard the attribute,
   and continue processing the UPDATE message.

   ...

   A NEW BGP speaker that receives a malformed AS4_AGGREGATOR attribute
   in an UPDATE message from an OLD BGP speaker MUST discard the
   attribute, and continue processing the UPDATE message

Although this section makes a reference to [ATTR-ERROR], my understanding upon reading
draft-ietf-idr-rfc4893bis-01.txt is that a malformed AS4_PATH or AS4_AGGREGATOR MUST be discarded
irrespective of the Partial bit in the Attribute Flags. Is this interpretation correct ?

(2) If the attributes AS4_PATH and AS4_AGGREGATOR are not marked as optional transitive, this should
result in a notification message, irrespective of whether this was received from an OLD or NEW speaker,
right ? Although this draft attempts to ignore attributes with errors, since it does not mention anything
specific about the attribute flags, I am assuming that the following section from RFC 4271 still holds good.

   Section 6.3.  UPDATE Message Error Handling

   If any recognized attribute has Attribute Flags that conflict with
   the Attribute Type Code, then the Error Subcode MUST be set to
   Attribute Flags Error.  The Data field MUST contain the erroneous
   attribute (type, length, and value).

Thanks,
Manish Vora
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