Re: Help Please - Reducing Routes

["Mike Norris" <]

Daniel
      this looks very good.  The message is clear, as is the syntax of
the summary.  

Question: how often will the robot run?  

Question: should the mail refer to policy-based routing and the 
          aspiration for coincidence between reality and policy as
          formally expressed in the routing registry, or would this
          dilute the purpose of the exercise?

I've added a few comments.

Cheers.

Mike


	Dear colleagues,

	I would like you all to help me a little with the text of an e-mail
	message I am about to program into a new robot.  This robot detects
	redundant BGP routes and brings them to the attention of the contact
	persons of the ASes concerned. 

	This is the direct result of the discussion we had at the last RIPE
	meeting about the need for reducing the number of routes and the
	consensus that we should mount a community effort to do something about
	it. 

	I would like you to read the example message below and give me
	sugestions for improvements.  It would also be useful to receive a short
	note saying "I could understand it, no suggestions", so that I can see
	how many actually tried to grok it. 

	Note that this is not picking in any way on AS1273.  I picked them
	because this message was the first one I saw that has all the optional
	elements in it.  I also know that the ECRC crew is good humoured in
	general ;-). 

That's true.  Also, their To: field looks almost like a limerick ;-)


	I hope to have the robot running sometime next week; but it is no good if
	people do not understand what they need to do. 

	So please help!

	Daniel


	From: Less Routes less-routes@localhost
	To:     "Dave F. Morton" dave@localhost,
	    "Todd Ferguson" todd@localhost,
	    "Kurt Kayser" kurt@localhost,
	    "Kurt Kayser" kurt@localhost,
	    "Waltraud Erber" wer@localhost,
	Subject: Routes AS1273 can help eleminate

	Dear AS1273 contact persons,

	as you may know the Internet routing system is quite strained at the
	moment.  The major cause of this is the number of routes in the system. 
	This has already caused some service providers to restrict the number of
	routes they propagate. 

	The RIPE NCC has analysed BGP routing tables and found that a
	significant number of routes (as many as 22% of the total) are
	apparently redundant.  Your autonomous system is either originating some
	of those redundant routes or one of your immediate neighbors is doing
	so. 

Give the source of authority for this mail by rewording the first 
sentence as follows:

At the request of its user community, the RIPE NCC has undertaken to
analyse BGP routing tables and finds that a significant number of routes
(as many as 22% of the total) are redundant.

 
	We have found redundant routes by looking separately at each set of
	routes which we observe coming to us though a unique set of BGP paths. 
	We believe that no routing information will be lost by eliminating
	redundant routes in in each set independently. 
                         ^^
No need for final adverb.  Sentence should end "..routes in each set."


	We have included all information about the redundant routes your AS is
	directly involved with and included it in the message below.  For each
	unique set of BGP paths observed in the routing table you will see a
	number of lines like

Rewrite the first sentence in the above par as:

We have summarised all information about the redundant routes your AS is
directly involved with and listed it in the message below.  


	- Paths:      <as-path> [/ <as-path> ...] 
	This is the set of AS paths observed in BGP routing. 

Explain what "Incomplete" means in sets of paths.  People could get
worried by this term.


	- Drop:       <prefix> covered by <less-specific-prefix>
	These prefixes can be dropped from global routing because they are
	covered by a less specific (shorter) prefix observed via the same set of
	paths. 

	- Aggregate:  <prefix> from <more-specific-prefix> & <more-specific-prefix>
	The more specific prefixes can be aggregated (combined) into a less
	specific one.  This works recursively, i.e.  aggregates of aggregates
	may appear.  This serves to show you how the aggregation was derived by
	us. 

Where possible, use the positive voice in the last sentence above:

This serves to show you how we derived the aggregation.

 
	- Announce:   <prefix>
	The announce lines show you all non-redundant routes for this set of
	paths including those that could not be improved.  This is what should
	be announced ideally. 

	- Prefixes:   <n>
	<n> is the number of prefixes observed via the set of paths. 

	- Dropable:       <n>
	<n> is the number of prefixes that can be dropped because they are
	covered by less specific prefixes (see above). 

	- Agg-able: <n>
	<n> is the number of prefixes that can be dropped because they can be
	aggregated into less specific prefixes (see above). 

	- Gainable: <n>
	<n> is the total number of prefixes that can be dropped without loosing
	information or routing functionality. 

Typo: "losing"

	We have compiled the information in two different sets: routes
	originated by your AS and routes originated by your AS's immediate
	neighbor ASes.  We only consider neighbor ASes that appear to be
	'downstream' from you from our point of view. 

	If your AS originates routes, please consider reducing the announcements
	as indicated by dropping and/or aggregating routes. 

	If you have multiple connections to (some of) your neighbors and you
	cannot aggregate or drop the announcements yourself because your
	immediate neighbor(s) need separate routes to choose the proper
	connection, please ask your neighbor(s) to do the aggregation for you. 

	If you have a legitimate reason for announcing prefixes that our model
	considers redundant, we are *very* interested to hear from you, so that
                                           ^^^^^^^^^^

Use "keen" or "anxious".


	we can improve our model.  Of course we are also interested in any
	feedback from you about the usefulness of this information to you and
	your willingnewss to use it. 
             ^^^^^^^^^^^^

Typo: willingness


	If the routes are originated by your neighbors, please contact them and
	bring this to their attention. 

	We will be collecting this information regularly and make it available
	at ftp://ftp.ripe.net/ripe/less-routes/ in file names of the form
	AS<num> where <num> is the AS number.  We will also regularly publish
	reports on the progress of this effort. 

	Please act now.  reducing the number of prefixes in the Internet routing
                         ^^^^^^^^

Typo: Reducing


	system is absolutely required to make routing more stable for everyone. 
                             ^^^^^^^^

Use "essential"?

	This affects you! 

	Thank you

	The RIPE NCC Routing Team