nanog mailing list archives
Re: ISP port blocking practice
From: "Robert E. Seastrom" <rs () seastrom com>
Date: Wed, 08 Sep 2010 15:52:27 -0400
Owen DeLong <owen () delong com> writes:
I know people at large ISPs with actual data. Port 25 blocking is quite effective.Does the data show that blocking was effective, as in the host didn't detect the block and proceed around it, or, merely that lots of hosts try the direct approach first?
Only a single data point and a few years old, but when I was at Inter.Net, my personal cell phone number was in the OrgTechContact for our blocks, we blocked port 25, and my cell phone rang like three times in a period of three years for calls regarding our netblocks. One was for "why is this machine scanning me?", two were "why is DNS geodata broken?". The latter two came within days of each other so I'm thinking news story or something. No spam complaints. YMMV, I'd do it again in a heartbeat though if I were running consumer edge. -r
Current thread:
- Re: ISP port blocking practice, (continued)
- Re: ISP port blocking practice Butch Evans (Sep 03)
- Re: ISP port blocking practice Owen DeLong (Sep 03)
- Re: ISP port blocking practice John Levine (Sep 03)
- Re: ISP port blocking practice Owen DeLong (Sep 03)
- Re: ISP port blocking practice John R. Levine (Sep 03)
- RE: ISP port blocking practice Paul Stewart (Sep 03)
- Re: ISP port blocking practice Doug Barton (Sep 03)
- Re: ISP port blocking practice Franck Martin (Sep 03)
- Re: ISP port blocking practice Owen DeLong (Sep 03)
- Re: ISP port blocking practice John R. Levine (Sep 03)
- Re: ISP port blocking practice Robert E. Seastrom (Sep 08)
- RE: ISP port blocking practice Brian Johnson (Sep 12)
- Re: ISP port blocking practice Patrick W. Gilmore (Sep 03)
- Re: ISP port blocking practice Ricky Beam (Sep 03)
- Message not available
- Re: ISP port blocking practice Patrick W. Gilmore (Sep 03)
- Re: ISP port blocking practice Claudio Lapidus (Sep 05)
- Re: ISP port blocking practice Patrick W. Gilmore (Sep 05)
- Re: ISP port blocking practice Franck Martin (Sep 05)
- Re: ISP port blocking practice Paul Ferguson (Sep 05)
- Re: ISP port blocking practice Jon Lewis (Sep 05)
- Re: ISP port blocking practice Owen DeLong (Sep 05)