A couple of days ago I did a planned software upgrade of an HP5406zl.

Since the installed firmware version was quite old it was not possible to update directly to the latest release, an upgrade path must be followed:

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Log analysis is important to both troubleshoot and understand network devices behavior.

Tail/less/grep are great tools that can help to filter and search hundreds or thousands lines of  logs.

If you prefer a GUI there are a couple of alternatives that can fit well.

For windows users only Log Expert is a great choice …

Today I had a chat about MTU with a customer. MTU is my second favorite topic for tech talks in front of the coffee machine, STP is still the first because there are so many misconceptions about it. Even QoS is funny, people has many creative ideas and expectations from it.

Let's talk about MTU. Everything begun today …

A few days ago a customer called worried by the flow control counters increasing on his Cisco 4510 switch, he just sent me this asking for an explanation:

CORE_4510#show interfaces flowcontrol
Port       Send FlowControl  Receive FlowControl  RxPause TxPause
admin    oper     admin    oper
---------  -------- -------- …

Last week I passed PW0-105 exam and obtained the CWNA certification:

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Wireless traffic packet capture is not easy as wired traffic. Linux and OSX have several solutions but if you're stuck with Windows the first problem is to find a compatible adapter.

My choice is AirPcap, fully compatible with Wireshark and very esay to install.

Install and setup

Download and install Wireshark and …

Networking is awesome but some tasks may be quite boring and repetitive. For  new campus network installations a lot of time is used just to put a basic initial configuration template on switches.

Each vendor has its proprietary method to distribute configs automagically but sometimes the effort to setup the system is …

Some time ago I've installed the new core switches for a customer: a couple of Nexus 7000, a couple of 5000 and twelve Nexus 2232TM, Virtual port channels, VLANs, Radius auth and so on.. all the usual configs a good network engineer does.

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This means two things:

• I'm CCIE for over one year now
• I need to prepare again the written exam

The last day to test the v4 edition is June 3, 2014, I've passed that exam twice so I expect a little effort to pass it again.

Ten years ago I've passed my first Cisco exam: CCNA! What was supposed to be just a marginal skill for a junior systems engineer became both my job and my passion.

Ten years and 21 Cisco exams later (and a bunch of other vendors), with 2 labs in Brussels, 1 FAIL and 1 PASS, I'm still excited about networking and I hope …

I took advantage of my participation at Cisco Live 2014 to book a free Cisco exam IUWNE. I passed with a strict margin but a pass is a pass right?

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Many network vendors are publishing simulators to the community. A simulator can be a way to complete a training or can be used for a PoC.

GNS3 maybe is the most famous emulator while others like eNSP for Huawei, Cisco's VIRL, Juniper Junosphere are available or will be available soon.

The big name missing so far was …