The revenge of the listening sockets

Back in November we wrote a blog post about one latency spike. Today I'd like to share a continuation of that story. As it turns out, the misconfigured rmem setting wasn't the only source of added latency.

It looked like Mr Wolf hadn't finished his job.


After adjusting the previously discussed rmem sysctl we continued monitoring our systems' latency. Among other things we measured ping times to our edge servers. While the worst case improved and we didn't see 1000ms+ pings anymore, the line still wasn't flat. Here's a graph of ping latency between an idling internal machine and a production server. The test was done within the datacenter, the packets never went to the public internet. The Y axis of the chart shows ping times in milliseconds, the X axis is the time of the measurement. Measurements were taken every second for over 6 hours:

As you can see most pings finished below 1ms. But out of 21,600 measurements about 20 had high latency of up to 100ms. Not ideal, is it?

System tap

The latency occurred within our datacenter and the packets weren't lost. This suggested a kernel issue again. Linux responds to ICMP pings from its soft Continue reading

Consumers don’t think they’ll get hacked

Most people say they care about their online security and privacy. Poll after poll confirm what one would expect: They don’t want their identities stolen, phones hacked, credit cards compromised or bank accounts drained. They don’t welcome government or anyone else conducting surveillance on them, especially in their private lives.But those polls also show that an alarmingly small percentage of those same people don’t seem to be willing to make much effort to do what they say they want – protect their privacy and security.To read this article in full or to leave a comment, please click here

This startup uses math to show whether your network is safe

How do you know your network is safe from attacks and failures? Veriflow, a startup with backing from the U.S. Defense Department, says it can make sure.Veriflow applies a practice called formal verification, used in preparing Mars missions and military gear, to figure out ahead of time what could go wrong on a network. Using that information, it helps enterprises apply policies to prevent problems from starting or spreading.If this sounds more at home in a lab than in a data center, it may be because that's where it came from. Veriflow's CTO, CSO and principal engineer are all longtime academics who worked on the problem together at the University of Illinois, and the National Science Foundation is a funder.To read this article in full or to leave a comment, please click here

This startup uses math to show whether your network is safe

How do you know your network is safe from attacks and failures? Veriflow, a startup with backing from the U.S. Defense Department, says it can make sure.Veriflow applies a practice called formal verification, used in preparing Mars missions and military gear, to figure out ahead of time what could go wrong on a network. Using that information, it helps enterprises apply policies to prevent problems from starting or spreading.If this sounds more at home in a lab than in a data center, it may be because that's where it came from. Veriflow's CTO, CSO and principal engineer are all longtime academics who worked on the problem together at the University of Illinois, and the National Science Foundation is a funder.To read this article in full or to leave a comment, please click here

High Availability Planning: Identify the Weakest Link

Everyone loves to talk about business critical applications that require extremely high availability, but it’s rare to see someone analyze the whole application stack and identify the weakest link.

For more details, watch my Designing Active/Active and Disaster Recovery Data Centers or attend one of my workshops.

If you start mapping out the major components of an application stack, you’ll probably arrive at this list (bottom-to-top):

Read more ...

Trump Hotels investigating possible payment card breach

The Trump Hotel Collection said on Monday it is working with the Secret Service and FBI to investigate a possible payment card breach, its second one in less than a year.The luxury hotel group is run by Republican presidential candidate Donald Trump and his family. "Like virtually every other company these days, we are routinely targeted by cyber terrorists whose only focus is to inflict harm on great American businesses," said Eric Trump, one of the candidate's sons, in an email statement. "We are committed to safeguarding all guests' personal information and will continue to do so vigilantly."News of the breach was first reported by computer security writer Brian Krebs, citing three unnamed sources in the financial sector.To read this article in full or to leave a comment, please click here

Interop Vegas 2016

I’m happy to be given the opportunity to speak once more at Interop Vegas in 2016. No workshop for me this year, but I will be putting on three individual talks, all focusing on topics that have been very near and dear to me over the past year. Last year I was very focused on putting the theory behind network automation into practical terms, and making it “real”. Over the past year I’ve seen rapid growth in adoption of these ideas, and I was happy to be just one very small part of helping to make that happen.

Interop Vegas 2016

I’m happy to be given the opportunity to speak once more at Interop Vegas in 2016. No workshop for me this year, but I will be putting on three individual talks, all focusing on topics that have been very near and dear to me over the past year. Last year I was very focused on putting the theory behind network automation into practical terms, and making it “real”. Over the past year I’ve seen rapid growth in adoption of these ideas, and I was happy to be just one very small part of helping to make that happen.

Interop Vegas 2016

I’m happy to be given the opportunity to speak once more at Interop Vegas in 2016. No workshop for me this year, but I will be putting on three individual talks, all focusing on topics that have been very near and dear to me over the past year.

Last year I was very focused on putting the theory behind network automation into practical terms, and making it “real”. Over the past year I’ve seen rapid growth in adoption of these ideas, and I was happy to be just one very small part of helping to make that happen.

Since the last Interop, my career has steered me towards a more direct approach to network automation, specifically through software development. So I’d like to spend some time providing an overview of my sessions at the upcoming Interop Vegas 2016, which are all inspired by the last year of my career.

Test-Driven Network Automation

I am obviously very passionate about network automation, and have been very vocal about my belief that network automation only has a chance if it is done properly, which includes proper testing. I strongly believe that network automation can and should take place within the context of a Continue reading

DNS OARC 24

For a supposedly simply query response protocol that maps names to IP addresses there a huge amount going on under the hood with the DNS. DNS OARC held a 2 day workshop in Buenos Aires prior to IETF 95. Here are my impressions of this meeting.

Intel’s top PC, IoT executives leave in management shakeup

The writing was on the wall for some Intel executives after a former Qualcomm executive was hired to oversee the company's PC, Internet of Things and software businesses, and two of them are departing.Kirk Skaugen, who previously led the Client Computing Group, and Doug Davis, who ran the IoT group, are leaving the company, Intel said Monday.Their roles were diminished after the November appointment of Venkata Renduchintala, who formerly worked at Qualcomm, as president of Intel's Client and IoT businesses and its Systems Architecture Group. Renduchintala, who's known as Murthy, is effectively Intel's number two executive after Brian Krzanich.To read this article in full or to leave a comment, please click here

IDG Contributor Network: Light will ultimately secure the Internet, scientists say

The Internet will eventually be secured from hackers by a technology called quantum photonics, say researchers. Single light particles will ultimately be used to exchange information in secure systems, they think. The technique is part of quantum computing. And now that a limitation has been overcome, the scientists at the University of Sydney say that the ultra-secure system is one step closer to realization. It’s been guessed at that photonics will be the future of security, however figuring out how to create a single photon has been holding back the forward movement in the research, the team says in a news release on the university’s website. They now think they’ve figured out how to do it.To read this article in full or to leave a comment, please click here

Brocade buying Ruckus Wireless for $1.2 billion

Networking hardware vendor Brocade announced today that it would add a wireless infrastructure club to its bag in the form of Ruckus Wireless, as part of a deal with a net value of $1.2 billion.The objective, according to Brocade’s public statement, is to broaden the company’s enterprise networking stable and boost profits, since wireless is a growth area. Like any merger of this type, the idea seems to be to offer a unitary set of products and services.+ALSO ON NETWORK WORLD: HTTP compression continues to put encrypted communications at risk + 12 powerful Windows 10 tools that hardcore PC enthusiasts will loveTo read this article in full or to leave a comment, please click here

Researchers reveal ‘Surreptitious Sharing on Android’ vulnerabilities

TU Braunschweig, Institute for Operating Systems and Computer Networks, Professors Dominik Schürmann and Lars Wolf are warning about a “Surreptitious Sharing” vulnerability which is present in many Android communication apps. Their pre-published research paper, Surreptitious Sharing on Android (pdf), is to be presented at the security conference GI Sicherheit 2016.To read this article in full or to leave a comment, please click here

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