Linode Forum
https://forum.linode.com/

Can outsiders identify a machine with 2 IP addresses?
https://forum.linode.com/viewtopic.php?f=19&t=3838		 Page 1 of 1
Author:  cboshuizen [ Wed Jan 21, 2009 6:50 pm ]
Post subject:  Can outsiders identify a machine with 2 IP addresses?
My linode has 2 IP addresses, and matching reverse DNS entries.

Can the outside net determine that these two IPs are on the same machine?

In particular, can webcrawlers and SMTP clients make such an identification?

If so, what commands can I run to see that myself?

I ask because I am interested in setting up a mailing list server separate from my main site, so as not to risk the spam rating of the main site. Is it necessary for these services to be split on completely different machines?

Thanks!

Chris
Author:  btmorex [ Wed Jan 21, 2009 7:11 pm ]
Post subject: 
Not really as far as I know. Given the 2 IP's they will know that they both are on linodes and both are in the same datacenter. If you have reverse DNS set up right (and you probably will if they're sending email), then they could look at registrations for DNS and guess. That's it though.

Quote:
I ask because I am interested in setting up a mailing list server separate from my main site, so as not to risk the spam rating of the main site. Is it necessary for these services to be split on completely different machines?


You shouldn't worry about that at all. I'd be much more worried about neighbors on your netblock spamming which can get the whole network on blacklists.
Author:  cboshuizen [ Wed Jan 21, 2009 7:32 pm ]
Post subject: 
OK, thanks for the quick answer.
Author:  bd3521 [ Fri Feb 20, 2009 1:25 pm ]
Post subject: 
The only thing they can find out is that linode owns both ips
Author:  cboshuizen [ Tue Feb 24, 2009 7:32 pm ]
Post subject: 
OK, that is great to know. Thanks for that!

Chris
Author:  ohkus [ Wed Feb 25, 2009 7:31 pm ]
Post subject: 
bd3521 wrote:
The only thing they can find out is that linode owns both ips


False!!!!!

ssh-keyscan is your friend....
Author:  Internat [ Thu Feb 26, 2009 1:29 am ]
Post subject: 
That of course assumes you have ssh running on both addresses which is easy to fix..
Author:  jsr [ Thu Feb 26, 2009 1:42 pm ]
Post subject: 
Yeah, there are a lot of ways depending on what services you have running and configuration of those services. For instance, most mail servers will by default attach to all IPs and it give out your real hostname.
Page 1 of 1 All times are UTC-04:00
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/