Educause Security Discussion mailing list archives
Re: Port 25 blocking
From: Michael Halm <Michael.Halm () CCMAIL NEVADA EDU>
Date: Fri, 5 Mar 2004 11:29:11 -0800
We are not blocking port 25. But we are redirecting port 25 traffic that does not originate with our list of authorized e-mail servers. We are doing this, of course, in response to the proliferation of variants of malware that installs an smtp engine on the infected machine. The purpose of the redirect is to inform us of the new smtp servers. The box that gets the redirected traffic simply logs port 25 activity and reports the hosts to us daily. We identify each machine and contact the owner, since in every case we need either to open a Help Desk ticket to disinfect the pc or else to authorize the server and add it to our allowed list. Michael Halm, CISSP Network Operations Center University of Nevada Las Vegas 4505 Maryland Parkway Las Vegas Nv 89154 702-895-0726 Tim Boshart <timsb () GOSHEN EDU> Sent by: The EDUCAUSE Security Discussion Group Listserv <SECURITY () LISTSERV EDUCAUSE EDU> 03/05/2004 11:10 AM Please respond to The EDUCAUSE Security Discussion Group Listserv To: SECURITY () LISTSERV EDUCAUSE EDU cc: Subject: [SECURITY] Port 25 blocking Our department has started to discuss blocking port 25 at our firewall for all machines except for our mail servers. How many places are doing this? Why did you implement this? -- Tim S. Boshart Information Technology Services Goshen College Voice: (574) 535-7004 Email: timsb () goshen edu http://timlinux.goshen.edu/ ********** Participation and subscription information for this EDUCAUSE Discussion Group discussion list can be found at http://www.educause.edu/cg/. ********** Participation and subscription information for this EDUCAUSE Discussion Group discussion list can be found at http://www.educause.edu/cg/.
Current thread:
- Port 25 blocking Tim Boshart (Mar 05)
- <Possible follow-ups>
- Re: Port 25 blocking Michael Halm (Mar 05)
- Re: Port 25 blocking Gary Flynn (Mar 05)
- Re: Port 25 blocking Michael_Maloney (Mar 05)
- Re: Port 25 blocking Clyde Hoadley (Mar 05)
- Re: Port 25 blocking Clyde Hoadley (Mar 05)
- Re: Port 25 blocking Douglas Burke (Mar 05)
- Re: Port 25 blocking Matthew Keller (Mar 05)
- Re: Port 25 blocking Sean Lanham (Mar 05)
- Re: Port 25 blocking Charlie Prothero (Mar 06)