docs/127290: FAQ book: discourage the use of port 53 for outgoing DNS queries

[Aleksandr Stankevic]

>Number:         127290
>Category:       docs
>Synopsis:       FAQ book: discourage the use of port 53 for outgoing DNS queries
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-doc
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          doc-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Sep 11 07:30:02 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator:     Aleksandr Stankevic
>Release:        
>Organization:
>Environment:
>Description:
http://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/security.html#EXTRA-NAMED-PORT

-- quote --
BIND uses a random high-numbered port for outgoing queries. If you want to use port 53 for outgoing queries, either to get past a firewall or to make yourself feel better, you can try the following in /etc/namedb/named.conf:

options {
        query-source address * port 53;
};

You can replace the * with a single IP address if you want to tighten things further.
-- quote --

We should discourage the use of query-source address * port 53 because of the last vulnerability in DNS.
>How-To-Repeat:

>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: