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: This is…
Log analysis is important to both troubleshoot and understand network devices behaviour. 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…
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…
A few days ago a customer called worried by the flowcontrol 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 …
In the very last day of availability of the CCIE v4 350-001 written exam I’ve renewed my CCIE for a couple of years more: My plan was to recertify with another track – Wireless or Security – but life happens…
Last week I passed PW0-105 exam and obtained the CWNA certification: I work with wireless network since 2005, I began installing some SoHo APs and in the last few years I designed and deployed many bigger networks, some of which…
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…
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…
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…
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…
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 later and 21 Cisco exams later (and…