[Last Call] Learn about multicloud storage options and how to improve your company's cloud strategy. Register Now

x
?
Solved

Port 80 blocked on just one site, and only from inside our firewall

Posted on 2004-03-29
10
Medium Priority
?
268 Views
Last Modified: 2013-12-04
Here's our odd situation that cropped up today....

We have a web server sitting outside our firewall using both HTTP and HTTPS.  From inside our network I can browse using the HTTPS port, but not HTTP.  I can browse any other server, either ours or anyone elses, with HTTP just fine, and anyone outside our network can browse to our server using HTTP (or HTTPS) also just fine.

All the servers are running Win2k and IIS.  We're running RRAS using NAT as our firewall.

Telnet to port 80 inside the firewall never connects.  Telnet to port 443 inside the firewall works fine.  From anywhere else (in the world) outside the firewall (including the firewall itself), port 80 opens as is normal.

(The obligatory...) This worked fine yesterday and (also the obligatory) no, there is nothing that we are aware of that has changed in any of the server configurations.  Again, we can browse anywhere else normally, just not this server.... but it WILL connect using HTTPS.

The server appears to be correctly configured to respond to both 80 and 443 for this particular web site.

Ok, have at it! :-)

Thanks,
Scott
0
Comment
Question by:shoge
[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
  • 4
10 Comments
 
LVL 5

Expert Comment

by:visioneer
ID: 10708145
Apparently your firewall is blocking port 80 from the inside to this box on the outside.
0
 

Author Comment

by:shoge
ID: 10708388
But then why would I be able to browse any other site?  If port 80 were blocked, then I would expect that I wouldn't be able to browse at all.
0
 
LVL 5

Expert Comment

by:visioneer
ID: 10708427
As I said, it's probably blocking from the inside to the box on the outside.  Specifically to that box.
0
Q2 2017 - Latest Malware & Internet Attacks

WatchGuard’s Threat Lab is a group of dedicated threat researchers committed to helping you stay ahead of the bad guys by providing in-depth analysis of the top security threats to your network.  Check out our latest Quarterly Internet Security Report!

 

Author Comment

by:shoge
ID: 10708582
Ok, the RRAS service on the firewall reports no input or output filters on either the LAN or WAN interfaces.  Also, no filters defined for the adapters themselves on either the firewall or web server.  If it's being filtered, I can't find it.
0
 

Author Comment

by:shoge
ID: 10708727
portqry does report that it is FILTERED.  I just haven't a clue as to where.

Here's the other odd thing... If I connect to the web site's address inside the firewall (it has two adapters and bridges the firewall) on port 80, it opens just fine.
0
 
LVL 5

Expert Comment

by:visioneer
ID: 10708954
You'll need to access the inside adapter from inside the firewall.
0
 

Author Comment

by:shoge
ID: 10709030
Well, that's our workaround for now, but I want to understand WHY this is happening. :-)
0
 
LVL 5

Accepted Solution

by:
visioneer earned 2000 total points
ID: 10709080
Some firewalls will not route an inside address to an outside address that is defined on the same firewall because the traffic has to go out and then back in.
0

Featured Post

Are You Ready for GDPR?

With the GDPR deadline set for May 25, 2018, many organizations are ill-prepared due to uncertainty about the criteria for compliance. According to a recent WatchGuard survey, a staggering 37% of respondents don't even know if their organization needs to comply with GDPR. Do you?

Question has a verified solution.

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

The term "Bad USB" is a buzz word that is usually used when talking about attacks on computer systems that involve USB devices. In this article, I will show what possibilities modern windows systems (win8.x and win10) offer to fight these attacks wi…
Article by: btan
The intent is not to repeat what many has know about Ransomware but more to join its dots of what is it, who are the victims, why it exists, when and how we respond on infection. Lastly, sum up in a glance to share such information with more to help…
Sometimes it takes a new vantage point, apart from our everyday security practices, to truly see our Active Directory (AD) vulnerabilities. We get used to implementing the same techniques and checking the same areas for a breach. This pattern can re…
In this video, Percona Director of Solution Engineering Jon Tobin discusses the function and features of Percona Server for MongoDB. How Percona can help Percona can help you determine if Percona Server for MongoDB is the right solution for …
Suggested Courses

656 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