Is Your Web Site on Virtual Contaminated Land?

When we set up a web site, how much thought should we give to the previous use of the Internet Protocol (IP) address and domain name? Any previous use could spell disaster for a new web site.

When you buy a house your conveyancing solicitor will undertake local searches and review the Home Information Pack. For commercial transactions, organisations will usually undertake some form of due diligence checks including enquiring about previous uses of the site and adjoining properties using old maps and information from the local authority. No-one wants to inherit the liability for contaminated land, for example from a previous gas works, tanning plant or dye manufacturer that occupied the site.

Instead of chemical threats, web sites need some virtual due diligence, when setting up a new site or moving to a new hosting company or domain. It may also be an issue if your hosting company is changing their IP address ranges and this affects your servers. The threats are to your organisation's reputation if it becomes associated with something contrary to its beliefs, objectives or might upset its customers, clients or users. It could also lead to a lack of availability if the address is blocked by spam or web filtering gateways.

The Domain Name Service (DNS) is responsible for translating between human-friendly domain names (e.g. www.clerkendweller.com) and and machine-friendly IP addresses (e.g. 217.33.198.55). If a hosting company loses a client, they are very likely to re-allocate their web site's IP address to a new customer.

For a new IP address on your existing domain (e.g. a server move), my recommendation is to obtain details of:

• How long the IP address has been allocated to the hosting company
• All domains assigned to the IP address previously
• Details of the organisations who own those domains
• Check what is hosted on 'nearby' IP addresses i.e. in the same address block
• Check what else is listed on the same domain name servers and the company who operates them

For a new web domain, check:

• Ownership history
• Current and prior internet usage (web, email, ftp, etc)
• Check the IP addresses for both of these (as above)

Then, evaluate whether there is anything you might not want to be associated with or has been excluded by web/email filtering/firewall systems due to what it has been used for or the content it contained. Check other server IP addresses as well (e.g. your mail server) if this is changing as well. Also check what else is hosted on 'nearby' IP addresses in the same range.

For a new web domain, use tools like Netcraft, Site Advisor, The Way Back Machine and Google searches to investigate prior use. Check with suppliers of web filtering gateways and providers of reputational services whether the domains are blacklisted.

For mail, the Spam and Open Relay Blocking System (SORBS) and Spamhaus list potentially problematic spam sources and open mail relays. There are many more similar searchable spam lists listed at dr.moensted. You may also want to check whether Hotmail, GMail and AOL treat the IP or domain as a source of spam.

If you are purchasing an existing domain name, as opposed to registering one from scratch, check its previous and current use. Some companies serve advert pages for domains they own but are not allocated to a web site - be very wary of these.

If your hosting company won't help with this enquiry, go elsewhere.