nanog mailing list archives
Re: Arrogant RBL list maintainers
From: Matthew Petach <mpetach () netflight com>
Date: Wed, 16 Dec 2009 09:21:42 -0800
On Wed, Dec 16, 2009 at 5:21 AM, <Valdis.Kletnieks () vt edu> wrote:
On Wed, 16 Dec 2009 07:06:55 EST, Mike Lieman said:What's the word for 'mail server' in Lower Sorbian, and does your algorithm properly detect it in a hostname? See the problem here?When the hostname at that IP address is exactly one incremented character different than the preceding address, and one decremented character different than the following address, and that pattern holds across a /24, they're probably not mail servers. Nobody has 256 'frzzmabs-1'..'frzzzmabs-256' servers in the same /24 for *anything* user-facing.
You clearly haven't set up webmail farms to handle half a billion accounts before. ^_^; We name our (many thousands of) webmail front end boxes as webXYYZZ.mail.$site.yahoo.com, so for cluster 3, farm 57, you end up with a string of hosts all in a row like web35701.mail.mud.yahoo.com web35702.mail.mud.yahoo.com web35703.mail.mud.yahoo.com web35704.mail.mud.yahoo.com web35705.mail.mud.yahoo.com web35706.mail.mud.yahoo.com web35707.mail.mud.yahoo.com web35708.mail.mud.yahoo.com ...etc... Take a look at the reverse DNS for the entire 66.163.178.0/23 subnet; you'll find that when you're doing things at large scale, you can't really get away from having sequentially numbered reverse DNS entries all in a row, exactly as you seem to think "Nobody has". :/ Matt
Current thread:
- Re: Arrogant RBL list maintainers, (continued)
- Re: Arrogant RBL list maintainers Michael Holstein (Dec 17)
- Re: Arrogant RBL list maintainers Rich Kulawiec (Dec 15)
- Re: Arrogant RBL list maintainers Adam Armstrong (Dec 15)
- Re: Arrogant RBL list maintainers James Hess (Dec 15)
- Re: Arrogant RBL list maintainers Suresh Ramasubramanian (Dec 15)
- Re: Arrogant RBL list maintainers Adam Armstrong (Dec 16)
- Re: Arrogant RBL list maintainers Mike Lieman (Dec 16)
- Re: Arrogant RBL list maintainers William Herrin (Dec 16)
- Re: Arrogant RBL list maintainers Valdis . Kletnieks (Dec 16)
- Re: Arrogant RBL list maintainers Jack Bates (Dec 16)
- Re: Arrogant RBL list maintainers Matthew Petach (Dec 16)
- Re: Arrogant RBL list maintainers Jack Bates (Dec 16)
- Re: Arrogant RBL list maintainers Valdis . Kletnieks (Dec 16)
- Re: Arrogant RBL list maintainers Matthew Petach (Dec 16)
- Re: Arrogant RBL list maintainers James Hess (Dec 15)
- Re: Arrogant RBL list maintainers Rich Kulawiec (Dec 16)
- Re: Arrogant RBL list maintainers Sean Donelan (Dec 16)