100% v6

I think that would make a good marketing slogan!

My current v6 experiment involves seeing how much of the networking into a particular machine can I get to be over IPv6? The machine I have chosen runs a web application and also has a windows file share on it (via samba).

So far the application is mostly using v6 as web stuff is easy. Samba was also easy as long as the clients where v6 enabled.

Its now down to the little things. DNS over v6 is the latest thing I'm working on but getting strange errors as the resolver can not do reverse lookups on IPv4 embedded addresses. These look like:

::ffff:10.1.2.3

I get loads of resolver errors on these. Command line nslookup works for name to IPv6 but reverse lookups are problematic.

Backups might be a difficult one to get working as its a vendor I will have to consult who might not care.

We'll see how far I can get.

My long term goal is to have all my internal systems use v6 by default.

Here's hoping.

CCNA Security

Yeah, I've been suckered in but hey, can't be that hard if it's a CCNA right?

So the other day I ordered my book and booked my exam. I've now got two months to get my brain into CCNA Security land but this shouldn't be that hard 'cos most of it is familiar already.

Here's hoping I make it through.

Pix Trix

For a long time, I had always assumed that hardware with no moving parts was almost bullet proof. Well the other day I had a switch loose is configuration out of the blue. Everything. When a bunch of machines dropped off the network it took me some time to track it down. When I finally connected a console to this switch I found it at the initial setup dialog.

Whoops!

So I set about restoring its configuration. No, I did not have a backup but I borrowed the configuration from another switch. The tricky part was working out the port configurations. I started by putting them all on the same VLAN which worked for most machines, until I discovered a PIX firewall that should have a trunking port.

Trunking to a firewall? Not the best way to do things, but hey it was a pissy little 506E so I didn't have a lot of choice beyond the two physical NICs. Configured on the firewall were two logical interfaces onto the physical. My first mistake was assuming that the physical interface would correspond to the native VLAN and the other two would be tagged via 802.1q

Well, would you believe that's not the case? I was scratching my head for a while since the other two interfaces were working fine as the switch was tagging their traffic but since I'd made the VLAN of the physical interface a native VLAN this meant its frames were not getting tagged by the switch and thus the firewall was not recognising them.

So after much deliberation I tested this by changing the native VLAN back to 1 and what do you know? It worked. Upon closer inspection of the firewall configuration it should have been obvious. Despite being listed as a physical interface there was still and entry in the VLAN field which meant that interface was looking for tagged traffic.

So now I know. Did you know?

Way Cool

I want one.

Sleepy Vista

I was very excited yesterday setting up my new work computer. I thought I should finally take the Vista plunge. It can't be that bad I said. This morning I turn up and hit some keys to wake it up. Nothing. Well no display. Had to power cycle the box to get something up. Google it. Yep, lots of people have had this issue. Yay, go Vista.

Now I have to spend an indefinite amount of time trying to solve this issue or turn of power saving, which is probably better 'cos my machine gets backed up at night.

Loading Fibre onto cable ship

Wow what a labour intensive process this is.

Back to my roots

I like my job. The reason? I get to wear many different hats by which I mean I get to exercise lots of different skills. This afternoon I have had a lot of fun getting back into my C programming. That's something that I hadn't done in a while and I was pleased to know most of it came back.

I have mostly finished a piece of glue software to import call detail records from our PABX into our database for billing. I have previously written it in C++ but wanted to whip something up very simple for testing and so in an afternoon (or two) I 've managed to get it working so that it can suck in files like the ones the PABX will spit out.

Of course that's only half the job, the next part is the data manipulation which will be tricky. Deciding who made a call is complicated and will most likely be a manual process. Deciding what room a call came from is easier. Putting that information together we can work out who we should bill for a call.

I believe it's still useful for programmers these days to have some old world skills like C. Yes C lets you make mistakes but how on earth do you learn to program without making some mistakes? When a language takes care of everything for you and hides all the details then you loose the perspective that you gain from understanding these things. Garbage collection is nice but it's good to understand why it's there and how it's a comprimise. Similarly pointers are ugly at times but they are very powerful. Sure you can abstract them out in C++ whilst retaining most of the power but real power must be dangerous and the pointers in C certainly are.

If you've only ever programmed in java or C# then you haven't really programmed. Sure logically thinking the problem through and breaking it down itno smaller problems is a useful skill but where's the debug skills in that? How do you learn what not to do and what is a bad way of getting a result if you don't break things in the process?

Oh well, I guess I'm still old school to boot.