I have recently heard companies saying their reasoning for de-aggregation was 1) to protect against outages to their customer base when a more specific of their aggregate was announced somewhere else and 2) if they are getting DDOS attacked on a given /24 they can just drop that advertisement and only affect part of their customer base. As technically savvy folks, we may not agree with this line of reasoning. However, keep in mind that the technically savvy folks are not always the ones making the decisions within a company. Just because someone has enable access and clue does not mean they have the authority to make certain decisions. Most of those people probably spend a large amount of their time arguing with the decision makers to try and do the right thing but at some point they lose those arguments. -- Justin Ryburn justin@ryburn.org -----Original Message----- From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] On Behalf Of Christopher L. Morrow Sent: Sunday, February 13, 2005 2:30 AM To: Alexander Koch Cc: nanog@merit.edu Subject: Re: The Cidr Report On Sun, 13 Feb 2005, Alexander Koch wrote:
On Sun, 13 February 2005 07:31:16 +0000, Christopher L. Morrow wrote: [..]
There are some business reasons to de-aggregate. Look at some outages caused by 'routing problems' (someone leaked my /24's to their peers, peers, peer and my traffic got blackholed, because the public net only knows me as a /20)
I am surprised you bring such an argument up. While we can surely agree on this happening on the net, I have yet to hear from someone saying this is happening more than once a month or so. Maybe Todd from
Renesys has other examples besides the Yahoo incident.^
if it happens once to you and lasts long enough... I'm not condoning it, nor saying it's even a valid reason to do it, just pointing out that it does happen :(
There are multiple reasons for deaggregation aside from 'dumb operator', some are even 'valid' if you look at them from the protection standpoint.
I won't argue that, but how many ISPs are using this line of argument? I have not heard anyone yet telling me this, not in years.
a few have... recently in fact.