Troubleshoot#2: Core Dumps for Network Engineers

Got a core dump file, please contact your TAC engineers for further support ! This is the common statement that we all see on vendors’ websites and in their recommendations and it definetly is true.  The reason is that a core dump file contains information that requires deep knowledge of the code of the cored …

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Google fixes 39 Android flaws, some allow hackers to take over your phone

Google has released one of the largest Android monthly security updates, fixing a total of 39 vulnerabilities — 15 rated critical, including four that can lead to a complete device compromise.The patches, which are included in new firmware images that were released Monday for the company's Nexus devices, will also be published to the Android Open Source Project over the next 24 hours.They include a fix for a vulnerability that Google warned about two weeks ago and which is already being exploited by a publicly available rooting application. Tracked as CVE-2015-1805, the privilege escalation flaw was originally fixed in the Linux kernel in April 2014, but it didn't become clear until February this year that it also affects Android.To read this article in full or to leave a comment, please click here

IDG Contributor Network: Will corporate sustainability save IT from itself?

Last week, flying out of SFO northward over the verdant hills of Marin, rising above the tankers anchored off Richmond swinging with the tide and the long plumes from the Sacramento River’s inflow to the bay like ribbons unfurling in the water, I reflected on a visit that touched five Silicon Valley sustainability stakeholders in two days. Enroute to my adopted home of Seattle, I am struck with the commonality of these sessions and an early release of Uptime Institute’s 2016 Industry Survey results. (Disclosure: I work for Uptime Institute and oversee the content group there.)There are new faces at the IT table. And one of them is sustainability. Two years ago, a place at the table for sustainability would have been provocative, and perhaps evoked derision. In 2015, less than a tenth of enterprise IT stakeholders had confidence in corporate sustainability to affect IT efficiency and costs. One short year later, 2016 is a vastly different matter and the data suggests that the time of corporate sustainability in IT is here now: 70% of enterprise IT organizations actively participate in corporate sustainability efforts. The influence of an outside party breaks down the ‘thwart by silo’ effect that Continue reading

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.