Cable Forum - View Single Post

lordy · 12-05-2006, 21:27

Thanks, I know its the reverse lookup of the IP, but I was hoping the IP and the reverse lookup was updated when DHCP doles out the IP address to a particular modem (ie DHCP updates DNS) , rather than NTL using a static list (which admittedly is what most IPs do!)

Eg from grc.com (not my favourite site but it may help to hear what I'm asking for in different words!)

"The string of text above is known as your Internet connection's "reverse DNS." The end of the string is probably a domain name related to your ISP. This will be common to all customers of this ISP. But the beginning of the string uniquely identifies your Internet connection. The question is: Is the beginning of the string an "account ID" that is uniquely and permanently tied to you, or is it merely related to your current public IP address and thus subject to change?"

Most fixed revers lookups that I've seen, contain the IP adress backwards ie 231_43_45_87-ntl-bromley.blah.net

Looks like NTL have gone for an 'unconventional' approach, if its permanently tied to the IP

Just odd that it contains 'cust<nnn>' ??

Just tried nslookup on a few cust<nnn> in sequence, and the IP did indeed go up in sequence, so I'll be quiet now!! I could have tried that before asking!!!

Thanks again!

12-05-2006, 21:27	#3
lordy Inactive Join Date: Dec 2005 Posts: 249	Re: Is Modem DNS Name Per IP or Per Account? Thanks, I know its the reverse lookup of the IP, but I was hoping the IP and the reverse lookup was updated when DHCP doles out the IP address to a particular modem (ie DHCP updates DNS) , rather than NTL using a static list (which admittedly is what most IPs do!) Eg from grc.com (not my favourite site but it may help to hear what I'm asking for in different words!) "The string of text above is known as your Internet connection's "reverse DNS." The end of the string is probably a domain name related to your ISP. This will be common to all customers of this ISP. But the beginning of the string uniquely identifies your Internet connection. The question is: Is the beginning of the string an "account ID" that is uniquely and permanently tied to you, or is it merely related to your current public IP address and thus subject to change?" Most fixed revers lookups that I've seen, contain the IP adress backwards ie 231_43_45_87-ntl-bromley.blah.net Looks like NTL have gone for an 'unconventional' approach, if its permanently tied to the IP Just odd that it contains 'cust<nnn>' ?? Just tried nslookup on a few cust<nnn> in sequence, and the IP did indeed go up in sequence, so I'll be quiet now!! I could have tried that before asking!!! Thanks again!