Feeds

Router crash downs CloudFlare services

A lesson in disclosure

HP ProLiant Gen8: Integrated lifecycle automation

During Sunday, US time, prominent Web services outfit CloudFlare sent an instruction to its routers in response to an attempted DoS, and instead took down its own network.

In a rare example of detailed disclosure, the company has posted an explanation of what happened here.

The network collapse occurred, the company explains, after it detected an attempted denial-of-service attack against a customer’s DNS servers using packets that were between 99,971 and 99,985 bytes long – an oddity, CloudFlare notes, because that’s so much larger than the Internet’s typical packet length (500 – 600 bytes according to the company) and larger than the 4,470 byte maximum packet it allows on its internal network.

So it wrote a JunOS rule (CloudFlare is a Juniper shop) to drop the packets, propagated the rule to its routers – and for reasons unknown, that rule crashed all the routers at which the instruction arrived.

“Flowspec accepted the rule and relayed it to our edge network. What should have happened is that no packet should have matched that rule because no packet was actually that large. What happened instead is that the routers encountered the rule and then proceeded to consume all their RAM until they crashed,” the blog post notes.

The crashes happened in such a way, CloudFlare says, that the routers didn’t reboot automatically, which meant that they couldn’t be accessed remotely; and worse, those routers that did wake back up copped the entire traffic load, couldn’t cope, and crashed again.

Accounts covered by SLAs will get credits, the company says, and it is investigating the problem with Juniper. ®

Maximizing your infrastructure through virtualization

More from The Register

next story
Google Nest, ARM, Samsung pull out Thread to strangle ZigBee
But there's a flaw in Google's IP-based IoT system
Orange spent weekend spamming customers with TXTs
Zero, not infinity, is the Magic Number customers want
Want to beat Verizon's slow Netflix? Get a VPN
Exec finds stream speed climbs when smuggled out
US freemium mobile network eyes up Europe
FreedomPop touts 'free' calls, texts and data
'Two-speed internet' storm turns FCC.gov into zero-speed website
Deadline for comments on net neutrality shake-up extended to Friday
GoTenna: How does this 'magic' work?
An ideal product if you believe the Earth is flat
NBN Co execs: No FTTN product until 2015
Faster? Not yet. Cheaper? No data
prev story

Whitepapers

Top three mobile application threats
Prevent sensitive data leakage over insecure channels or stolen mobile devices.
The Essential Guide to IT Transformation
ServiceNow discusses three IT transformations that can help CIO's automate IT services to transform IT and the enterprise.
Mobile application security vulnerability report
The alarming realities regarding the sheer number of applications vulnerable to attack, and the most common and easily addressable vulnerability errors.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.