Lazy Engineers and Viable Excuses

Stephen J. Wilcox steve at telecomplete.co.uk
Wed Aug 27 18:16:50 UTC 2003


> --On Wednesday, August 27, 2003 9:36 AM -0400 Leo Bicknell 
> <bicknell at ufp.org> wrote:
> 
> > In a message written on Wed, Aug 27, 2003 at 12:15:18AM -0400, John Payne
> > wrote:
> >> If this is true, then why do the european NAP mailing lists (which push
> >> IRR  filtering) have an almost constant stream of "oops, our customer
> >> announced  everything to us and we leaked it".
> >
> > Because European naps have more smaller and clueless players.  I
> > know more than a few people (because they ask for peering) who have
> > an IRR entry that is 1 prefix for the "ISP", and 1 prefix for their
> > only BGP customer.  It should be of no surprise they get that
> > customer configured wrong.  It should also be of no surprise that
> > most of the real ISP's would never consider peering with those types
> > of networks.
> 
> CAIS (or whatever they're called today - BtNAccess/PCCW) is a small and 
> clueless player?  Then why is 6461 peering with 3491?
> 
> 
> (yeah, that was a customer route leak in July.  I tend to just delete such 
> emails, but I'd be surprised if there weren't more in August from ISPs that 
> don't fit into "small and clueless")

there have been leaks by some large networks "tier1" if you like

you dont know what caused the route leaks tho..

eg modifying cisco route-maps and filters by deleting and re-adding opens a
small window of opportunity in which a lot of announcements get through, if your
CLI pauses during this window or something causes you to be disconnected its
instant route leak

i quote the above as i know of more than one occasion where this has occured to
bad consequences

you can think of others eg the filter building script has a bug in it etc etc


better to try and fail than to not try at all imho

> Not everyone filters their customers, and saying that everyone that counts 
> does doesn't make it so.
> 
> >6461 filters all customers by prefix list.  Note too, filtering
> >customers does not eliminate route leaks, it just removes the most
> >obvious and often cause.
> 
> Really?  So how was I able to advertise a new netblock to one of your 
> customers just now and see 6461 <their AS> <my AS> on 
> route-views.oregon-ix.net within 2 minutes and without telling a soul what 

good question, however as an ex-customer I know MFN do filter.. perhaps you're 
announcing that many that your being filtered on as-path of prefix count? try 
announcing something naughty and see if it goes thro eg rfc1918 or the block 
with windowsupdate on .. that should increase your traffic volume ;p

Steve




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