Useful Network Links

These are some useful links that I use for gathering information about networks in my day to day job as a networking consultant

• Everything you ever wanted to know about a particular DNS, Domain or IP Address.
  
  
• Everything you want to know about a UK place and also does funky coordinate transformations.
  
  
• A Netmask/Broadcast Address/Network Address Calculator.
  
  
• A nice reference site with the IP, UDP, TCP, ICMP IPV4 protocol options and formats displayed nicely and fully. It has other IP Suite references as well (eg a large list of standard Port numbers.
  
  
• Internet Query Tools hosted at Demon. These tools allow you to find out compehensive information on a host, domain or an IP address.
  
  
• Spam Tracker This is a quick and dirty general purpose internet address lookup thingy that will also tell you whether it is a known source of spam.
  
  
• osirusoft is another way of finding out whether an IP address is on the spam blacklists.
• Verify MX record accessibility. This link allows you to determine whether a domain has some MX records and whether they are all likely to work.
  
  
• Smurf Amplifier Registry A place where you can find out whether your network can be used for smurf attacks. It contains a database and checking CGI.
  
  
• Networking Virus/Trojans List this is a useful little list of TCP/UDP ports that are used in probes against remote systems and the names of the programs that do it.
  
  
• "What does my firewall mean when it says..."An explanation of which ports do what in a firewall log. There are links off to other useful information pages from here as well.
  
  
• IP Protocol Numbers This is a list of the assigned values of the PROTO field in an IP header.
  
  
• Well Known Port Numbers This is a list of the of the well known port numbers either assigned or registered with IANA. If you want a 'complete' /etc/services file (unlike the one you probably have been supplied with) you can cobble it together from here.
  
  
• UK Telephone Code Locator Find out where someone in the UK is telephoning from when you dial 1471.
  
  
• Fire Forensic CDROM is a freely downloadable ISO image containing a linux kernel + windows binaries for conducting forensics (or maintenance) on a machine that has been infected or otherwise failed.
  
  
• SysInternals has a range of free M$ exploration and monitoring tools as do FoundStone.

I am always on the lookout for useful network exploration facilities, if you have such then please let me know.