carrier comparison

Vlade Ristevski vristevs at
Tue Feb 11 13:50:31 UTC 2014

I got the RFO today and what happened was:

" The Cogent NOC investigated and found that one of our customers 
connected through a Verizon aggregated circuit to the router was being 
DDOS attacked. This type of attack can send excessive traffic to a 
customer’s interface either deliberately or accidentally, causing a 
spike in the router’s CPU usage. The Cogent NOC shut down the attacked 
customer’s connection to the network restoring normal router operations 
and our Customer Service Group worked with the customer to resolve the 
DDOS issue."

On 2/7/2014 4:42 PM, Faisal Imtiaz wrote:
> This is exactly what I thought had happened....The outage that affected you was one our two routers up-stream from your connection to that provider.
> I am not trying to defend any Carrier, but there is no 'routing protocol' what will react to this kind of an issue.....
> Regards.
> Faisal Imtiaz
> Snappy Internet & Telecom
> 7266 SW 48 Street
> Miami, FL 33155
> Tel: 305 663 5518 x 232
> Help-desk: (305)663-5518 Option 2 or Email: Support at
> ----- Original Message -----
>> From: "Vlade Ristevski" <vristevs at>
>> Cc: "nanog list" <nanog at>
>> Sent: Friday, February 7, 2014 3:57:00 PM
>> Subject: Re: carrier comparison
>> We don't get a default route from them. At the time of the outage my bgp
>> session was up and I had a full routing table from them.  I didn't have
>> much time to troubleshoot it in that state since we were down so I had
>> to disable the session ASAP. Once the RFO comes in, I'll be asking a lot
>> more questions about it. My only experience with BGP is as a customer so
>> I'm not too familiar with the intricacies on the provider side. We had
>> an outage in the AM the same day and we failed over just fine. I'm very
>> curious why the same didn't happen in the evening.
>> On 2/7/2014 3:03 PM, Bryan Socha wrote:
>>> Did you verify your problem was announcements on the other side of the
>>> outage?   This sounds to me like you are using a bgp announced default
>>> route from cogent which is always sent.    I think the problem was you
>>> were sending traffic out a path that was broken.   Since you mentioned
>>> your outbound balancing this would explain some packet loss and not
>>> 100% loss.
>>> Bryan Socha
>>> Network Engineer
>>> DigitalOcean
>> --
>> Vlade Ristevski
>> Network Manager
>> IT Services
>> Ramapo College
>> (201)-684-6854


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