In August of 2002, IANA changed the status of 69/8 from Reserved to assigned to ARIN. Unfortunately, it is still being filtered as a bogon by routers and firewalls all over the Internet.
In March of 2003, ARIN assigned a block of 69/8 IPs to Atlantic.Net. Knowing from prior threads on the NANOG mailing list (alternate archive in case Merit moves theirs again) that these IPs would have "reachability issues", I decided some kind of testing would have to be done before assigning any of these IPs to customers or important servers. With access to a very large list of mail server IPs, I decided it would be a good idea to ping each of these IPs from a non-69/8 address and from a 69/8 address and make a list of which IPs were reachable from non-69/8 space, but not from 69/8. Once an IP in a /24 had been reached from 69/8 space, other IPs in that /24 were ignored and assumed to be reachable. I later realized this might not be a very good assumption since some of the unreachable IPs have been networks as small as /32 static-IP DSL users. After the initial ping sweep was completed, I had a list of about 1000 IPs unreachable from 69/8. I'd then planned to write some code to send automated messages to the NIC contacts for the unreachable IPs. But after manually contacting the first dozen or so of the largest unreachable networks, I realized automating the process would not be practical. Often, the filters were not maintained by the end user of the unreachable IPs. The end users were not always interested in the problem, and would refer me to their provider (shouldn't they care about not having full Internet access?). And it was sometimes not at all clear who was responsible for the filters. So, this site has been setup with the hope that it will draw attention to the issue and those who maintain unreachable networks will be encouraged to fix their filters.
We have a database of IPs which are unreachable from 69/8 address space, yet are (or at least were at one time) reachable from non-69/8 address space. It's believed that most of these IPs are behind routers or firewalls using outdated bogon filters blocking packets from or routes for 69/8. If you cannot access this site via this alternative URL to a host name using a 69/8 IP address, then your Internet connection is likely behind such a misconfigured router or firewall.
We also have a traceroute utility that you can use to simultaneously traceroute to any destination from a 69/8 IP and a non-69/8 IP.