I'm a part of a .mil organization with a group of users that are trying to reach a website that is part of another .mil domain not within our forest. They can access the website just fine, but the website performs a reverse lookup before giving a user access to a group of subsystems; if the user's public IP does not reverse back to a .mil host then you will be denied some of your access. This is the current problem this website is having. I called the DNS folks that the particular .mil website points to and I confirmed that they can not perform a reverse lookup using nslookup from their workstation as well. I should also note that they CAN perform a forward lookup on our records just fine.
My first step to make sure that the problem was not on our end was to run a reverse lookup of our namespace using public dns lookup tools, such as www.mxtoolbox.com
. I can perform a forward and reverse lookup against our proxy hostname and a few other nodes as well without issue. I also confirmed with my directory service folks in charge of DNS that all of our records are in place.
Does anyone know what the potential problem may be? What things should I be looking for when a remote site can perform a forward lookup, but not a reverse lookup. No other known remote site is having this issue with hitting our PTR record... just this one site it seems.