Firewall Wizards mailing list archives
Re: Interesting DNS Traffic
From: The Unicorn <unicorn () blackhats org>
Date: Mon, 31 May 1999 14:59:18 +0200
On Fri, May 28, 1999 at 09:49:29PM -0500, Andrew Fessler wrote:
I have seen some unusual things on my Cisco. I have some access-lists setup. I permit, SMTP, WWW, POP, IMAP, ECHO,ICMP and a few other ports as well as 1024-65535 for inbound. That theroetically should cover any inbound traffic. However, I see DNS requests and WWW requests come in where the souce port on the packet originates in the 800 range rather than the standard 1024-65535 range. Therefore the reply back is denied. Example. xxx.xxx.xxx.xxx (879) --> 204.253.83.10 (53) meaning a packet came in from the internet going to my DNS, however the source port of the packet was 879. I cant find any reason why they are having abnormal source ports, should I worry about this? Should I open the 800 range ports? Seems like opening my network more than I want to.
Could it be that the site asking for DNS info is using (heavily used) Windows boxen? I have seen similar requests (originating from a low order port) coming form Windows systems... Seems to be an implementation "feature" from Micr$oft.
TIA Andrew Fessler Allegro
---end quoted text--- Ciao, Unicorn. -- ======= _ __,;;;/ TimeWaster ================================================ ,;( )_, )~\| A Truly Wise Man Never Plays PGP: 64 07 5D 4C 3F 81 22 73 ;; // `--; Leapfrog With A Unicorn... 52 9D 87 08 51 AA 35 F0 ==='= ;\ = | ==== Youth is Not a Time in Life, It is a State of Mind! =======
Current thread:
- Re: Interesting DNS Traffic The Unicorn (Jun 01)
- <Possible follow-ups>
- Re: Interesting DNS Traffic Robert Graham (Jun 01)
- Re: Interesting DNS Traffic Joseph S D Yao (Jun 02)
- Re: Interesting DNS Traffic Andrew Fessler (Jun 01)
- Re: Interesting DNS Traffic Ryan Russell (Jun 02)
- Re: Interesting DNS Traffic David Gillett (Jun 03)
- Re: Interesting DNS Traffic Vern Paxson (Jun 02)
- Re: Interesting DNS Traffic -Reply Einar EINARSSON (Jun 02)
- Re: Interesting DNS Traffic -Reply Ge' Weijers (Jun 03)
- Re: Interesting DNS Traffic -Reply -Reply Einar EINARSSON (Jun 03)
- Re: Interesting DNS Traffic -Reply -Reply Ge' Weijers (Jun 04)
(Thread continues...)