A Clue Bat was gently swung by a friendly and clueful (semi-anonymous) AOL NetOps guys who contacted me from my post on Nanog. Thanks Nanog, and this sounds strange from me, but Thank's AOL. :)
And yes, it should have been obvious on my part.. a router was configured with a 172.0.0.0/8 netmask. > ......there is what we call an RFC1918 issue. AOL was given > some IPs in the 172.16.x.x range by ARIN. These are valid routable IPs, > and we use them as IPs for the AOL user's machines (kinda like DHCP). The > problem is that some people block all of 172.x.x.x thinking it's only for > non-routable IPs when it's only half that range that is non-routable. > (172.16.0.0/20 is the routable part). That appears to be the case with > this one. We've asked ARIN for a different range, and they told us to go > away, so we are stuck with this issue. If you can ask someone who does > firewall and/or router ACLs in front of that website, they should be able > to fix the issue.
