Solved

Weird Cisco / Port 80 Web Site Access Issue

Posted on 2006-10-23
4
329 Views
Last Modified: 2007-02-13
Fairly simple configuration, Westell DSL modem, and Cisco 1811W integrated services router configured with BVI interface and Dialer0 interface for DSL connection.

As of last night, did some DSL modem troubleshooting (changed DSL modem from "router" mode to "bridged ethernet" mode), and now client can browse any web site on the internet EXCEPT for Yahoo, and their web site hosted by Yahoo.

On the client PC I can telnet to Port 80 on Yahoo.com and get a connection, and in Internet Explorer, for a split second, displays the page title in the title bar of the browser, then suddenly stops and displays "Cannot find server or DNS error".

This makes absolutely no sense to me. Suggestions? Urgent. :(
0
Comment
Question by:BrandonPotter
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
4 Comments
 
LVL 9

Assisted Solution

by:crawfordits
crawfordits earned 100 total points
ID: 17789687
Review the hosts file located in c:\windows\system32\drivers\etc.  Should look like this:

# Copyright (c) 1993-1999 Microsoft Corp.
#
# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
#
# This file contains the mappings of IP addresses to host names. Each
# entry should be kept on an individual line. The IP address should
# be placed in the first column followed by the corresponding host name.
# The IP address and the host name should be separated by at least one
# space.
#
# Additionally, comments (such as these) may be inserted on individual
# lines or following the machine name denoted by a '#' symbol.
#
# For example:
#
#      102.54.94.97     rhino.acme.com          # source server
#       38.25.63.10     x.acme.com              # x client host

127.0.0.1       localhost
0
 
LVL 7

Assisted Solution

by:instillmotion
instillmotion earned 100 total points
ID: 17791784
Does this happen on all local machines?
Does it only happen in IE?
Please for testing purpouses, install firefox: http://www.mozilla.com/en-US/firefox/
Do you have the same issues with firefox?
0
 
LVL 1

Accepted Solution

by:
rpone605 earned 300 total points
ID: 17806402
You might want to check the MTU settings on both the cisco and westel devices.
0
 

Author Comment

by:BrandonPotter
ID: 17806452
OK, tried all of the above comments, and stumbled upon the solution:

Apparently somewhere in the process of establishing the Dialer0 interface through Switch Device Manager, the "Inspect nonstandard HTTP traffic" was checked, with a policy action of "Drop".

Cleared this and all was well. However, unchecked "Inspect HTTPS traffic" and then HTTPS did not work at all. Weird, just checked it back and HTTPS is not blocked anymore.

Interesting Cisco animal, the 1811W + SDM.
0

Featured Post

Free Tool: Site Down Detector

Helpful to verify reports of your own downtime, or to double check a downed website you are trying to access.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

If you're not part of the solution, you're part of the problem.   Tips on how to secure IoT devices, even the dumbest ones, so they can't be used as part of a DDoS botnet.  Use PRTG Network Monitor as one of the building blocks, to detect unusual…
ADCs have gained traction within the last decade, largely due to increased demand for legacy load balancing appliances to handle more advanced application delivery requirements and improve application performance.
Michael from AdRem Software outlines event notifications and Automatic Corrective Actions in network monitoring. Automatic Corrective Actions are scripts, which can automatically run upon discovery of a certain undesirable condition in your network.…
Monitoring a network: how to monitor network services and why? Michael Kulchisky, MCSE, MCSA, MCP, VTSP, VSP, CCSP outlines the philosophy behind service monitoring and why a handshake validation is critical in network monitoring. Software utilized …
Suggested Courses
Course of the Month7 days, 6 hours left to enroll

622 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