Solved

Allow DNS lookups with Cisco ACL

Posted on 2006-11-20
2
339 Views
Last Modified: 2008-01-09
I currently use ACL's on my Cisco 2600 series router to block as much of what I don't want as possible.  The lines that pertain to my web server are:

access-list 116 permit tcp any host <my web IP> eq www
access-list 116 permit tcp any host <my web IP> eq 443
...followed by a "deny all"  at the end.  

Now, however, I need to allow this web server to access a few other web sites, and it appears that my only issue is that I can't get results from my ISP's DNS server.  I thought this line should do it:

access-list 116 permit udp any host <my web IP> eq domain

I can access a site by using a specific IP address, but I still can't resolve any domain names.  How do I alllow DNS with ACL's?

Thanks!
0
Comment
Question by:DBrecht
2 Comments
 
LVL 43

Accepted Solution

by:
JFrederick29 earned 250 total points
Comment Utility
Close.  Change it to this:

access-list 116 permit udp any eq domain host <my web IP>
0
 
LVL 2

Expert Comment

by:shekharbasnet
Comment Utility
Or if you need a more tighter rule:

access-list 116 permit udp host <dns IP> eq domain host <my web IP>
0

Featured Post

Free Trending Threat Insights Every Day

Enhance your security with threat intelligence from the web. Get trending threat insights on hackers, exploits, and suspicious IP addresses delivered to your inbox with our free Cyber Daily.

Join & Write a Comment

Suggested Solutions

Problem Description:   Couple of months ago we upgraded the ADSL line at our branch office from Home to Business line. The purpose of transforming the service to have static public IP’s. We were in need for public IP’s to publish our web resour…
Creating an OSPF network that automatically (dynamically) reroutes network traffic over other connections to prevent network downtime.
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

744 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

9 Experts available now in Live!

Get 1:1 Help Now