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Tech

Force DD-WRT to use OpenDNS Servers for DNS Queries

In one of my recent articles, I explained how I set-up a guest wireless network for our work place (after getting it to work with the right wireless channel :))

After configuring the guest access point, I set up the DNS servers to point to OpenDNS in order to provide a safer and faster DNS service (compared to the default DNS servers our ISP provides) as well as choosing what web-sites should be allowed on the network.
For example, bandwidth hogging (Media/Video Sharing) and other web-sites which could potentially be used for illicit purposes (P2P/File Sharing) are forbidden on the network.

However, without any firewall rules on the router itself, it would still be possible for a guest on the network to change their DNS settings on their wireless adapter to point to any other DNS server; effectively bypassing all OpenDNS filters on the network for that specific client.

Categories
Tech

Installing TCPDump on DD-WRT WRT54GL

This article will serve as a quick tutorial on installing TCPDump on a LinkSys WRT54GL box running the custom DD-WRT firmware.

TCPDump is a command line packet analyser. It’s a bit like Wireshark except it is command line based and in this tutorial, we will be installing it on a router and not on a PC.