Problem : The server forwarders cannot be updated, The IP address is invalid. Even though the IP’s are valid

Problem : The server forwarders cannot be updated, The IP address is invalid.  Even though the IP’s are valid

Hi there, I am trying to add in another one of my ISP’s as a forwarder in my forwarder table.  Currently I have two listed and when I try to add the others or try to even add one I receive the error: The server forwarders cannot be updated.  The IP address is invalid.  In case you are wondering the IP’s are 207.115.64.2 and .172.  I verified them from my ISP.  I setup my laptop to use that as an exclusive DNS server and I cannot do an NSLookup on anything.  When I hard code in one of the other DNS servers that I currently have listed in my forwarders tab it resolves just fine and I can get on the internet.  (This is the goal here)

When I type it in it even resolves the FQDN, while the others (that work) say unable to resolve).  It is almost like these are not setup to forward DNS requests.  Is there something else that I need to look at in DNS to get this to work?  I have just never noticed this error before when the IP’s are valid.


 

Solution: The server forwarders cannot be updated, The IP address is invalid.  Even though the IP’s are valid

From what I can gather the problem seems to be that those servers are configured not to respond to recursive queries.  This makes them useless as forwarders, although they work as DNS servers for direct queries.  If I test them through DNSStuff, what I get is a response that the query was referred to the authoritative DNS server for whatever domain I was looking up. So, instead of doing the recursion (i.e., looking up the address at the authoritative server and responding to your query) you’re getting a response that your server can’t interpret.