The most important way to maintain the perimeter network is to stay informed. Make sure to get the most up-to-date information on new security issues and fixes for the products you use as quickly as possible. The best way to do this is to subscribe to appropriate mailing lists and vendor security alerts (see the following sections in this chapter). I recommend subscribing to the mailing lists and vendor alert services that are relevant to your system and network.
In my opinion, mailing lists are the best forum for discussion and for following computer security-related issues. By keeping up with the mailing list discussions, you are aware of potential issues as they happen. Mailing lists are also easy to use. The only downside is that some lists may have a rather high volume (I define this as being more than 30 messages a day). For this reason, I recommend using some kind of server-based message handling system that can file messages to different mailboxes. This keeps your “inbox” clear from all list messages.
If you’re on a Unix system, I warmly recommend the Procmail mail processing software (http://www.procmail.org/ ). If you’re using Exchange, you can set up rules to filter your mail. There are also filtering capabilities in some email clients such as Outlook that do client-side filtering.
Bugtraq is a full disclosure moderated mailing list about security issues. Bugtraq is maintained and moderated by Elias Levy (a.k.a. Aleph One). According ...