Pinging is an easy way to determine if communication is possible between two hosts, but sometimes you need more information than an ICMP echo request can provide. hping is a nifty command-line tool that allows you to use different protocols and the features of those protocols to test how a host will respond to different scenarios. It can be a strong ally for network analysts who want to find all the holes in their network before the bad guys do.

hping can be used to send TCP, UDP, ICMP, or even raw IP packets. It also gives you almost full control of the packets’ makeup. You can test what ports are available, if your firewall is fooled by fragmentation, how the TOS value affects router performance, and many other things by combining command-line options to tailor pings to different test situations.

hping can also be educational. Just playing with this tool can teach you a lot about what’s involved with transmitting information from one point to another. If you haven’t seen an IP header since your college networking class, it will all come back to you pretty quickly.

Each Thursday, Security Musings features a security-related technology or tool. Featured items do not imply a recommendation by Gemini Security Solutions. For more information about how Gemini Security Solutions can help you solve your security issues, contact us!

This entry was posted on Thursday, May 21st, 2009 at 6:53 pm by Mike Markiewicz and is filed under Technology & Tool Thursday. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.