[c-nsp] NTP DDoS

Aaron aaron1 at gvtc.com
Mon Feb 17 21:29:31 EST 2014

My gosh!  NTP ddos attacks are coming like crazy lately.  Y'all getting hit

I'm going to need to setup a bgp injection thingy with my upstream providers
to signal a /32 for my victim(s) in my network so I can selective blackhole
traffic in the cloud prior to it hitting my internet links..... this is
getting really bad


-----Original Message-----
From: cisco-nsp [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of
Richard Clayton
Sent: Tuesday, February 11, 2014 3:36 PM
To: Cisco NSPs
Subject: [c-nsp] NTP DDoS

Seems to be doing the rounds, had a fault open for a couple of days with a
100Mb Ethernet customer, reported fault was packet loss, Cacti showed an
upstream flatline of 30Mb and an increase in downstream, as the circuit
traffic had recently increased 1st line support presumed that the BT
Wholesale circuit had an Etherflow bandwidth restriction so raised the fault
which ping ponged back and forth until BT washed their hands of it (rightly
so on this occasion) When it was escalated to me I noticed 'no buffer' and
'pause input' packet counters were going nuts on the LAN interface, the
packet counters were 10k packets/sec, I enabled 'ip route-cache flow' on the
WAN interface and there it was, 1000's of NTP connections.

In summary the Cisco 1921 gave up at 30Mb/s with no buffer left, usually
runs fine at 100Mb/s with no NAT config, customer had public IP on LAN
switch for management and open NTP, LOL.

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