non-existent domain/IPv4/IPv9 issue

This is my first post on this board. I hope someone can help me. I am not being allowed access to a message board that I used to frequent alot. The site is URL. When I try to log on, a page comes up saying this:


Access to this website is currently not possible as your hostname/IP appears suspicous.

I wrote to the admins for the message board. This is the response I got back:




You are accessing this server from a network address that is not
resolving from a valid IPv4 or IPv9 type domain by the message
board. Your host domain is not identifiable and it is your IP
address is the issue.

There is a great deal of technical information on the subject that
can be found by doing a search on Google using any of the key
references. IPv4 IPv9 non-existent domain

In brief, the use of non-existent domains has become a major problem
on the Internet and one that has become a serious problem for message
board operators. Unfortunately, not only is the use of these domains
an exploitation of the Internet protocol standards; they are also
widely used to exploit message boards. We had been allowing access
from these domains, but this access has become problematic and we can
no longer support it.

If you cannot access our sites and are getting the message that your
IP address is suspicious, please contact your Internet service
provider and advise them of the situation. This is the only way to
resolve the problem.

This is not a deactivation or a denial of service; please feel free
to forward this email to your ISP



I never had a prblem before accessing this site. I called my ISP, and they said that my IP address is valid, and not not-existent. So I have no idea what's going on. Any help would be greatly appreciated.


thanks, Todd

uhm, so what's your IP? It can be found at www.whatismyip.com

This is my IP address. I am not much of a computer guru, so just ask me if you need any other info and I will comply.

thanks, Robert Beistel
209.247.222.49

You:

209.247.222.49 resolves to unknown.Level3.net
unknown.Level3.net resolves to www.Level3.net
www.Level3.net resolves to 209.245.19.42

Me:

68.51.39.58 resolves to pcp456607pcs.shklfd01.ar.comcast.net
pcp456607pcs.shklfd01.ar.comcast.net resolves to 68.51.39.58

There's 2 differences between our IPs.

1) your IP resolves to an alias which is then resolved to a domain. Mine just resolves to the domain.
2) The domain your IP resolves to points to a different IP then your own. My domain points back to my IP.

If XMB won't let you in cause you're using an alias (1), then that's a bug in the XMB code. But if XMB won't let you in cause your domain doesn't resolve to your IP, then this is level3's fault. IP's should always resolve to domains that resolve back to the original IP.

You can contact your ISP and point them to this topic so that they get the information they need to fix this problem with their DNS if they are so willing.

P.S. If anybody happens to know how XMB validates IPv4 then let us know.

Thank you for the advice. You really know your stuff my friend. I forwarded this to my ISP in hopes they can resolve the issue. It's really weird to me. I can access other message boards, but just not rush.net. Some of my friends said I was banned for visiting a rival message board. The counterparts message board. I don't know if this is true or not, but I didn't know anything about the fact that a feud was going on between the 2 boards. I seem to have been caught up in the crossfire. Thanks again for the info.

No, it has nothing to do with you visiting another board. It's something specific to the XMB board. There are configuration options to turn on or off ipcheck.