A bad week for the home LAN
I didn’t have time to update this blog last week. Most of my free computer time was spent on recovering my home linux server.
Tuesday evening, the three months old 500GB SATA disk of my home server crashed! And it crashed big time. Nothing but ‘tak-tak –tak’ and it was impossible to recover anything from the damn thing.
Fortunately, I had setup an rsync which synced all my data and most of the server configuration to an external USB disk every night. Not much data was lost.
But, even then, restoring the server took more time than I expected. This is mostly because I learnt the hard way that having all the config files on a backup is not a guarantee for a fast restore. Installing all the apps (with dependencies), compiling some soft, compiling a custom kernel for the motherboard takes a LOT of time.
Therefore I have taken my precautions in case the replacement disk should decide to go on permanent leave in the near future. I googled a bit and found mkCDrec. This neat tool allows one to create a bootable recovery CD set from the entire system including installed applications. When necessary, you can boot with the CD set and quickly restore the system in the state when you created the disks.
So from now on, whenever I make big changes to the system. I just run mkCDrec, save the ISO images to my external disk and that’s it: I am a little better prepared for when Murphy strikes once more.
Next on the improvement list: buy a small UPS for when lightning strikes 
ISP trouble & Tech Support fun.
Starting last Thursday, I am experiencing intermittent problems with my home cable Internet connection.
After investigating what was going on, I came to the conclusion that my Linux Router/Firewall was not able to get a lease from my ISP. I confirmed my findings by disconnecting the linux box and connecting my laptop directly to the cable modem. WireShark showed the same as tcpdump did on the linux box: Whilst I was sending out DHCP DISCOVER packets, I got no DHCP OFFERS whatsoever from the almighty DHCP server.
I decided it was time to call my ISP’s helpdesk…
After dialing the number, a computer voice told me that they tested the modem and the ISP’s infrastructure is working perfectly. Now this is already enough to work on my nerves as there might be a million other things wrong with my ISP’s infrastructure besides the poor cable modem. Next a first line helpdesk guy picked up the phone. After I explained him I did not see any packets returning to my DHCP offer, he told me to ‘click start –run – cmd.exe – ipconfig/renew’… sigh
After pushing the guy a little, he finally came to his senses and to the conclusion that it might be a cable modem related issue but he immediately covered his back by stating ‘all costs for sending a technician might be for my account if the problem was not related to the cable modem (which is owned by the ISP)’ …sigh again.
So I asked the guy: ‘How can I be sure it is the cable modem according to you?’ He answered to unplug any device from the modem and wait for 2 hours (lease expiry) before reconnecting any device and then try to connect again. Fair enough, so I unplugged the RJ-45 plug from my cable modem and waited for two hours. After two hours still no lease.
The next day, I called the helpdesk once more (again a voice stating that the modem is working like a charm) and this helpdesk guy tells me that what his colleague said was wrong. I needed to unplug the modem, wait two hours (apparently the lease expiry + reset time of their setup) and try again. He told me that the old model of (CDLP) modem I have is known to block DHCP offers from time to time. The new (DOCSIS) modems do not have this problem and reset far easier so he said.
Another two hours of waiting later, I was able to get a lease right away. Happiness followed and the universe was in balance again or so it seemed.
The joy was only for a short time as today; my Internet connection suffered an outage of one hour once more. Now, I understand that my Internet connection has no SLA whatsoever but I do need this connection to work from home and I never had this frequency of outages in the past. The logs of my linux box showed the same problem. It could not renew his lease during the time of the outage.
Another call to the helpdesk and they are sending over a technician to investigate. Although the support guy still said that the techie house call might be invoiced to me if the problem is not related to my modem…. The technician coming over would be the judge of that.
Hopefully the onsite-techie will replace the modem this Friday or otherwise I am very close to short circuit the modem so I DO get a NEW one and good service once more.
How NSA access was built into Windows
A friend of mine sent me an email today with a link to an article stating how NSA access was built into Windows.
Although, it seems that this news is quite old, I only heard from this today. In my opinion, it is very scary that there are master keys for the encryption in Windows. This means that the NSA can look into your encrypted data at any time.
Now, while that may be handy for the NSA, what would happen if a disgruntled employee of the NSA/Microsoft dropped this ‘magic’ key on the black market. Suddenly anyone willing to pay for it could decypher your precious encrypted data. Scary stuff.
So, my suggestion is not to use the MS implementation of Encrypted File Systems but go with Open Source solutions like TrueCrypt . At least for the OS soft, the code can be reviewed by others.
Tom