Loosing Connection To Internet

[wtangle]

Users on the network keep getting disconnected from the Internet while browsing in IE or Firefox. The loss of Internet connection is random. It has happened on my computer as well; I could be listening to a podcast then I try to access any other website only to find that I have lost connection to the Internet... the podcast continues without interruption during this time. Several minutes later I have internet access back from the browser, sometimes we have to restart the computer to get connected back to the Internet.

We have UT in bridge mode, connected between the router and LAN switch. I captured packets using Wireshark yesterday when I lost connectivity and it shows lots of "Connection reset (RST)" errors. I have attached a section of the TCP message as shown by wireshark. Can anyone make sense of this message and why this could be causing us to loose Internet connection through the browser only. During this time, we can ping any external website using the domain name. This makes me believe that it is not a DNS issue. Thanks.

[dmorris]

Try the steps here where you have outages: http://wiki.untangle.com/index.php/The_internet_is_down

It sounds like UDP and ping work, but not TCP. Is it not allowing new connections or just connections get reset?

Describe your network & hardware & setup.

ps - loose rhymes with goose.

[wtangle]

DMorris, Thanks for the quick response. Below are my answers to the troubleshooting steps you point out:

On the Untangle server
* Use the connectivity test, Does it succeed? - YES
* Using the ping test, can it ping Untangle's gateway? - YES
* Using the ping test, can it ping 8.8.8.8? - YES
* Using the ping test, can it ping google.com? - YES
* Using the connection test, can it connect to google.com port 80? - Haven't tried

On a client behind untangle
* Can the PC ping Untangle's external IP? - YES
* Can the PC ping Untangle's gateway? - YES
* Can the PC ping 8.8.8.8? - YES
* Can the PC perform DNS lookups? (Open a command window and run 'nslookup google.com' or 'host google.com') - YES
* Can the PC ping google.com? - YES
*** Can the PC open a browser to google.com? - NO ***
* Can the PC open a browser to Untangle's internal administration interface? - YES

Network & hardware & setup:
HP Compaq Presario, Dual Pentium 4 3.2 GHz, 2.65 MB memory.
Router <--> Untangle <--> Switch <--> Other LAN switches <--> Workstations.

[sky-knight]

Do you by chance have a mail server protected by said Untangle as well?

[wtangle]

I forgot to mention that it is not allowing new connections. I don't know what you mean by connections getting reset?

[wtangle]

Originally Posted by sky-knight

Do you by chance have a mail server protected by said Untangle as well?

We don't have a mail server, ours is hosted outside our network.

[sky-knight]

In that case do you have the attack blocker installed?

[wtangle]

Yes, attack blocker is installed. Here is how the attack blocker event log looks (attachment)

[dmorris]

Originally Posted by wtangle

DMorris, Thanks for the quick response. Below are my
* Using the connection test, can it connect to google.com port 80? - Haven't tried
*** Can the PC open a browser to google.com? - NO ***

Give that a try.

And instead of opening a browser to google.com telnet to port 80 and see if its connects.
also, try this from untangle itself.

It looks like everything works *except* TCP.

you don't have multiple racks or any policies that would block traffic at certain times do you?

[sky-knight]

.122 if it isn't a server... it's sick.