RE: IP announce DOS

["David Gillett" <gillettdavid () fhda edu>]

  Did you get your Class C address from the relevant authority (ARIN,
APNIC, RIPE, etc)?  Or is it one that the old ISP assigned you, out
of address space assigned to them?  [It sounds like you think the
former case applies, but since this is the "basics" list, I can't
entirely assume that.]

  If there were a technical fix, a way to have BGP say "THIS is the
One True Path to AS ____", then everyone would enable it and we'd
be right back where we started....

  Do you know your old ISP's upstream providers?  A competent ISP
will have at least two, but if they're small they might not have 
more than that.  Perhaps they can be persuaded not to accept that
ISP's announcement of this block?

David Gillett


> -----Original Message-----
> From: Alex Thurlow [mailto:buddychrist () gmail com]
> Sent: Wednesday, June 08, 2005 2:24 PM
> To: 'security-basics () securityfocus com'
> Subject: IP announce DOS
>
>
> I'm not positive this is the correct list to ask, but it is a 
> security 
> concern, so I thought I would.  The company I work for had T1 lines 
> running to our office provided by a local provider.  We had our own C 
> block of IPs being announced by them and routed to us over 
> those T1s.  
> Our relationship with them went sour (for many reasons I 
> won't get into 
> here), and we had to move to a different provider.  We had 
> the routing 
> switched over to them.  Everything was fine.  Here it is a few weeks 
> later, and suddenly our old provider starts announcing these 
> IPs again.  
> The end result is a partial DOS attack (hence writing to this 
> list) as 
> some people can't reach us.  They won't stop the 
> announcement.  I don't 
> know all the details on what they've said there as it's now gone to 
> executives and legal people dealing with them.  Is there 
> anything we can 
> do here from a network standpoint?  Someone we can report 
> them to?  How 
> do people protect themselves from just anyone announcing IPs 
> that aren't 
> theirs?
>
> Thanks in advance,
> Alex Thurlow
>
>
> ________________________________________
>
> SKYLIST
> Email Marketing Solutions that Deliver
> Service You Can Trust
>
> You are receiving this email message
> from a representative of SKYLIST, Inc.
> 13171 Pond Springs Road, Austin, TX 78729
> Toll Free: 877.250.2922
>
> To cease all communication with SKYLIST, visit
> http://www.skylist.net/unsubscribe
> or send an email to unsubscribe () skylist com