I had the pleasure of attending the CCIE Wireless tectorial at Cisco Live in San Diego this year. One of the topics discussed was the new diagnostic section of the lab. Jerome Henry gave us insights into what the section would look like as well as some examples of the types of things that we can expect in the section. I wanted to pass on some of that information along with a few insights about how you should prepare for this section since it’s quite different than what we’ve seen before in the lab.
What is the Diagnostic section?
Starting in v3 of the wireless lab, each lab will begin with a 1-hour diagnostic section. This section has no configuration task associated with it. Instead, you will be playing the role of TAC, or a senior level engineer. Your job is to look at information gathered from a client by a first-level engineer and analyze it so that you can answer questions related to troubleshooting an issue.
It sounds like you can expect maybe 3-4 separate troubleshooting scenarios with approximately 10 questions to answer across those 3-4 scenarios. So that means there will probably be 2-4 questions per scenario. All Continue reading
A one-stop shop that targets IT, not just service providers.
I’ve been wrestling with an Ubuntu network configuration issue over the last couple of weeks (off and on between working on other projects), and today I finally found a fix for the problem. The issue was that Ubuntu wouldn’t pick up changes to network interfaces. The fix is so simple I’m almost embarrassed to talk about it (it seems like something that I should have known), but I’m posting it here in case others run into the same issue.
Here’s a bit more context: I was switching some of the network interfaces in my Ubuntu 14.04.2 servers from a “standard” network configuration to using VLAN interfaces (after all, it seemed like such a shame to not more fully utilize the 10GbE and 40GbE interfaces in these servers). Before the reconfiguration, the servers had a network interface configuration file (located in /etc/network/interfaces.d
and sourced in /etc/network/interfaces
) that looked something like this:
auto p55p1
iface p55p1 inet static
address 172.16.3.201
netmask 255.255.255.0
This interface was connected to a port on a Cumulus Linux-powered Dell S6000-ON that was configured as an access port on a particular VLAN. Everything seemed to work just Continue reading
Cisco's security obsession creates an exit for the DNS startup.
Over the last couple of weeks, the networking industry has made some significant steps in the right direction, the open networking direction. At the Open Networking Summit (ONS), we heard some great news about the disaggregated network and how open networking is now everywhere from hyperscale to the enterprise to startups to telcos. As exciting as that is, that’s not the news I’m referring to — I’m referring to the announcement of the Open Networking Testing Consortium.
To illustrate why this is big news, I’ll give some background on how open networking has been operating for most people. Up until a few years ago, the way you purchased a bare metal switch was through select APAC sources and a wire transfer. A few weeks later, you’d receive your equipment and it was then up to you, the end user, to perform interoperability testing with your cables and optics manufacturers while on the phone with support, along with bootstrapping your OS to these boxes. Eventually you had both a CapEx and OpEx saving solution that you controlled from end to end.
Luckily for most of you, that experience has now been refined significantly Continue reading