IETF Logo Mail Archive

RE: [curtis@ans.net: Re: BGP4 stuff: Local Preference Computation]

"NITTMANN Michael (MSMail)" <MNittmann@shl.com> Mon, 09 September 1996 20:49 UTC

Received: from ietf.org by ietf.org id aa06821; 9 Sep 96 16:49 EDT
Received: from cnri by ietf.org id aa06817; 9 Sep 96 16:49 EDT
Received: from merit.edu by CNRI.Reston.VA.US id aa13859; 9 Sep 96 16:49 EDT
Received: (from daemon@localhost) by merit.edu (8.7.5/merit-2.0) id PAA21084 for idr-outgoing; Mon, 9 Sep 1996 15:39:17 -0400 (EDT)
Received: from interlock.ans.net (interlock.ans.net [147.225.5.5]) by merit.edu (8.7.5/merit-2.0) with SMTP id PAA21079 for <bgp@merit.edu>; Mon, 9 Sep 1996 15:39:14 -0400 (EDT)
Received: by interlock.ans.net id AA07160 (InterLock SMTP Gateway 3.0 for bgp@ans.net); Mon, 9 Sep 1996 15:38:54 -0400
Received: by interlock.ans.net (Internal Mail Agent-2); Mon, 9 Sep 1996 15:38:54 -0400
Received: by interlock.ans.net (Internal Mail Agent-1); Mon, 9 Sep 1996 15:38:54 -0400
Message-Id: <c=US%a=_%p=SHL%l=SHL/CANADAW/001BBC22@cocms1.calwdc.shl.com>
Sender: ietf-archive-request@ietf.org
From: "NITTMANN Michael (MSMail)" <MNittmann@shl.com>
To: Curtis Villamizar <curtis@ans.net>, "NITTMANN Michael (MSMail)" <MNittmann@shl.com>
Cc: "bgp@ans.net" <bgp@ans.net>, "John G. Scudder" <jgs@ieng.com>, Yakov Rekhter <yakov@cisco.com>
Subject: RE: [curtis@ans.net: Re: BGP4 stuff: Local Preference Computation]
Date: Mon, 9 Sep 1996 12:43:31 -0600
X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.837.3
Encoding: 59 TEXT
X-Orig-Sender: owner-idr@merit.edu
Precedence: bulk


----------
From:  Curtis Villamizar[SMTP:curtis@ans.net]
Sent:  Monday, September 09, 1996 12:10 PM
To:  NITTMANN Michael (MSMail)
Cc:  John G. Scudder; Yakov Rekhter; bgp@ans.net
Subject:  Re: [curtis@ans.net: Re: BGP4 stuff: Local Preference Computation] 



>In message ><c=US%a=_%p=SHL%l=SHL/CANADAW/001B58E6@cocms1.calwdc.shl.com>l.com>, 
"NITT
>MANN Michael (MSMail)" writes:
>> I like the table, but would like to change a little detail:
>> 
>> 			   Type of Connection
>> 	Attribute	Internal	External
>> 	---------	--------	--------
>> 	ORIGIN		mandatory	mandatory
>> 	AS_PATH	mandatory	mandatory
>> 	NEXT_HOP	mandatory	mandatory
>> 	MED		optional		mandatory   <<<<<<<<
>> 	LOCAL_PREF	mandatory	forbidden
>> 	ATOMIC_AGG	*		*
>> 	AGGREGATOR	optional		optional
>> 
>> make the MED exchange for mutually set MEDs mandatory for the routes that 

>> are concerned, i.e. if I am in AS 1 and peer with AS 2, all AS 2 routes 
>> announced to me must carry the MED value assigned to them by AS 2 towards 

>> me, AS 1, or -1 if there is no MED set.
>> 
>> Mike
>
>Mike,
>
>What you are saying doesn't make sense to me.  MED is non-transitive.
>It is optional for EBGP.  It MAY be passed from EBGP into IBGP.  It is
>NEVER passed from IBGP to EBGP.  It is perfectly legitimate to not
>pass a MED at all in either IBGP or EBGP.
>
>Curtis

MED should be transitive and mandatory on all ebgp connections; doesn't look 
so difficult to me.

BTW, if I understand this right, and I always skipped over that part because 
it is not relevant for a BGP state machine:

these 4 bits, what's the purpose at all? Are the property bits for 
attributes in fact part of the transmitted protocol message (transitive, 
etc....)?

Any real use transmitting protocol definition elements in run time PEs? 

Mike

v2.8.7 | Report a Bug | By Email