Category: networking

  • Upgrading the Options (GlobeTrotter) GI515m

    Recently I needed to install an Options (GlobeTrotter) GI515m 3G USB modem on a machine which previously used an older version of the modem (the iCON 225). This seems a pretty common scenario (an existing user getting an update), however the process seems less-than-straight forward: Get a second computer with the same operating system version […]

  • Creating a non-MAC bound CentOS 6 machine

    I was building VMs to be deployed with Vagrant / Virtualbox for our QAs and discovered that on new instantiations of the machine the networking interface wasn’t coming up. The problem was that Virtualbox was assigning a random MAC address to the NIC (and rightly so, to avoid conflicts). I used the following steps to […]

  • Manually enabling IP routing in Windows XP

    While Internet Connection Sharing is a nifty tool, there are some cases where you would like to do the steps manually. One such case would be if the “primary” network is already using the 192.168.0.1/24 address space, since ICS is hardcoded (as far as I can tell) to use the same network. One concrete case […]

  • Why you should use 0.0.0.0 in your hosts file – redux

    Some time ago I (wow, time files!) I suggested that using 0.0.0.0 for host-file based blocklists would be faster than using 127.0.0.1. Above you can see an other reason for using 0.0.0.0: some applications take up port 80 on the localhost and accessing it can (potentially) create havoc. In the example above TeamViewer (which is […]

  • Remote debugging with Java

    Sometimes you have the situation that an issue is only occurring on certain machines or only at a certain time of day. There are a couple of possible methods to investigate such an issue (like: adding extra logging), however I would like to add an other one: remote debugging trough TCP/IP. To do this, start […]

  • Parsing pcap files with Perl

    Recently I was reading the blogpost on the BrekingPoint labs log about parsing pcap files with Perl and I immediately said to myself: it is impossible that there isn’t a module on CPAN, because Perl is great. Turns out I was right, there is Net::TcpDumpLog which can be combined with the NetPacket family of modules […]

  • Why network neutrality is a big deal

    Reposted from the packetlife blog. We already pay for the bandwidth. The content providers already pay for the bandwidth. Anyone claiming anything different is either very misinformed or is straight out lying!

  • Network Forensics Contest submission

    Some time ago I mentioned the Network Forensics Puzzle. The contest is now over and since I didn’t win, I’ll publish my submission below – it was after all correct, but not quite what the judges were looking for (congratulation to the winner). After validating that the MD5 sum for the downloaded file matches the […]

  • T2’09 Challenge

    Sorry for being a little late: the T2’09 challenge just started. Via the F-Secure weblog. Don’t be fooled by the fact that page already contains two entries (“Mr. Speed” and “Mr. Style”) in the top. From what I understand, these are to signal that two winners will be selected, one for speed and one for […]

  • If you can’t access Windows shares…

    A small Windows tip: if your computer is part of a domain and all of the sudden you can’t access resources over the network (like shares, printers, etc), try changing your password. I observed this in several networks, and although I’m not entirely sure about the reason – I suspect that it has something to […]