Wednesday, 23 January 2013


I've seen this happen for a few reasons but had a new one today.

We had a new 3750 that I'd set to DHCP on VLAN1 to plug in.  I then changed the native VLAN to 111 and added voice etc VLANs

Then we plugged a phone in and started seeing the Windows DHCP server fill with BAD ADDRESS entries and when you cleared them the came back in seconds.

Hmm.. unplugged the phone and PC on the back of it.  Still filled the DHCP table.

Turns out the core switch had VLAN1 decommissioned but it still had a helper and so the new switch's DHCP requests on VLAN 1 were going to the server and turning up as short MAC addresses (8 or 10 characters) and Windows went no, next and so on.

Odd. I would have thought it would have said no range defined and ignored it.  So the helper must be doing something bizarre.

Moral of the story:  look for stray helpers on your layer 3 devices as another source of BAD ADDRESS problems.

Sunday, 13 January 2013

Alfa Romeo 155 handbrake not working

My other love apart from technology is cars.  Especially Italian and English ones and for the last decade or so especially Alfa Romeos...

They're a bit quirky but they feel nice, the sound nice, they look nice. They're just a nice place to be :-)

One thing I've run into a couple of times that I want to know so I remember it and other may save some time.

Alfa 155 handbrake: leave it high!

The handbrake if set to low will stop the rears auto adjusting and you'll lose rear braking  (and be all nosey when you brake hard) and the handbrake will be next to useless. Leave the hand brake about 45 degrees and you'll be fine.

Any one know where to find exhaust cam follows for a v6 155?  I'll pay handsomely for that info!

Switch your Raspberry Pi 3 to use a hard drive

I have a Pi 3 that is a DNS, web, email etc server and it's gone through a few SD cards and gets bogged down in high wait % in top somet...