Full Disclosure mailing list archives
Re: Reverse dns (whether you want it or not)
From: "Dave Korn" <davek_throwaway () hotmail com>
Date: Fri, 11 Mar 2005 13:48:05 -0000
"TheGesus" wrote in message news:5e70f65305031013083747d7b () mail gmail com...
On this subject (marginally), last year we moved a rather large CIDR block from one ISP to another. The new ISP took it upon themselves to give *ALL* our unused IP addresses a bogus reverse lookup in the (general) format of 10.20.30.40.abc.domain.com No one asked them to do this (or, at least if they did, they won't admit to it), and none of the reverse lookups can be looked up "forwardly". Is this a common practice? It doesn't seem like a good idea, but the ISP insisted it was a "value-added" service. In my opinion, a dead address should remain dead.
It's common. ISPs don't want to have to update their DNS records with every single client that logs on or off their network, that would be a lot of churn and general overhead for no great purpose. Plus it's always good to avoid leaking information. If a lot of those machines have firewalls that block ping etc, to present a 'stealthed' low attack profile to the world, it would be a shame to give away the information about which IPs were genuinely dead and which were firewalled off but had live machines behind them to anyone who wanted to look it up in the DNS. cheers, DaveK -- Can't think of a witty .sigline today.... _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://www.secunia.com/
Current thread:
- Reverse dns Paul Schmehl (Mar 10)
- Re: Reverse dns Vincent Archer (Mar 10)
- Re: Reverse dns Paul Schmehl (Mar 10)
- Re: Reverse dns Duo (Mar 10)
- Re: Reverse dns Paul Schmehl (Mar 10)
- Re: Reverse dns Duo (Mar 10)
- Re: Reverse dns Danny (Mar 10)
- Re: Reverse dns (whether you want it or not) TheGesus (Mar 10)
- RE: Re: Reverse dns (whether you want it or not) Edward Ray (Mar 11)
- Re: Reverse dns (whether you want it or not) Dave Korn (Mar 11)
- Re: Re: Reverse dns (whether you want it or not) Danny (Mar 11)
- Re: Reverse dns Paul Schmehl (Mar 10)
- Re: Reverse dns Valdis . Kletnieks (Mar 11)
- Re: Reverse dns Simon Biles (Mar 11)
- Re: Reverse dns Vincent Archer (Mar 10)
- Re: Reverse dns Paul Schmehl (Mar 10)
- Re: Reverse dns Valdis . Kletnieks (Mar 11)