Re: DNS ACL ?

[jnemeth () victoria tc ca (John Nemeth)]

On Apr 3,  3:10am, John Hally wrote:
} 
} I need a sanity check regarding DNS ACLs.  For external facing DNS servers
} you need to allow only udp/53 inbound, correct?  I know tcp/53 is used for

     No.

} zone transfers and requests/replies greater than a certain size, but they
} shouldn't typically happen for general dns queries correct?  

     Depends on the size of the query.  Which in turn depends on how
your DNS is setup (i.e. do you have hosts with a large number of A
records, do you have a number of MX records {queries for these usually
return the A records as 'Additional Info'}, or have AAAA records?).
Also, don't forget about your secondaries if they happen to be
offsite.

}-- End of excerpt from John Hally

------------------------------------------------------------------------------
Audit your website security with Acunetix Web Vulnerability Scanner: 

Hackers are concentrating their efforts on attacking applications on your 
website. Up to 75% of cyber attacks are launched on shopping carts, forms, 
login pages, dynamic content etc. Firewalls, SSL and locked-down servers are 
futile against web application hacking. Check your website for vulnerabilities 
to SQL injection, Cross site scripting and other web attacks before hackers do! 
Download Trial at:

http://www.securityfocus.com/sponsor/pen-test_050831
-------------------------------------------------------------------------------