Connectivity issue between two Windows systems on the same network - networking

I am trying to set up a license server for a CAE software.
Server side everything is working fine, logs are clean and the application successfully reaches the licensing server locally.
I have fixed by configuration the listening ports and opened them on the firewall, so I moved to the next step which was setting up the clients.
The first one worked fine and successfully connects to the licensing server, while the second returned error.
I tried to run a Test-NetConnection to those ports with Powershell from both machines and as expected it worked for the first one while it didn't for the second. Ping succeeds but TCP connection fails.
What could be the issue?
Thanks everyone for your time and support.

Related

Cannot open new SSH connections after a certain amount of time

I have a web server running Alpine linux and OpenSSH. When I power on the server, for about an hour or two I am able to open SSH connections and send commands fine. However, after that, even though the server is up, it does not respond to pings and I cannot SSH in to it. The server is still running, and I can still access the website being served from it. Why does this happen, and how can I avoid it?

SMB - Server never responds to Session Setup Request

I am having very strange network problems. I am on a domain where a few servers are located on a different subnet. I can ping these servers, dns look them up and remote desktop to them by IP-address. I however cannot find them when using:
net view \server
or
Try to access them via windows explorer.
The person next to me who has an identical machine and is on the same subnet has no problems, as a matter of fact, I am the only one in a 50 person company having this problem!
This wouldn't be so much of a problem except for the fact that my machine cannot use web services located on these servers, neither via HTTP or NET.TCP.
After trying everything I can find on the internet and some more (added a new network card, reset policies, etc.) I finally got WireShark to see what is going on. When doing net view \server I notice that the server never responds to "Session Setup Request" but it did respond to "Negotiate Protocol Request". So what could possibly cause the server never to responde to the Session Setup Request?
Here is the server side capture (Not same session)
OK I found out what this was by comparing my tcpip registry (HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters) with a machine that worked. What I noticed is that I had the following 2 entries
EnablePMTUBHDetect 0
EnablePMTUDiscovery 1
but the other machine didn't. By deleting these entries, everything started working!
This however is very strange because these happen to be the default values for there registry keys so I do not understand why having these entries cause such a problem.

Windows Server 2008 R2/IIS 7 refuses all outside tcp connections

I am unable to connect, for example, via http to a brand new installation of 64-bit Windows Server 2008. The server is on a domain, but is not DC (that's another problem altogether).
The IIS7 is running on the server and the website is accessible locally via http://localhost, but when I try to connect from another machine on the same network, the connections is refused, even though Windows Firewall is disabled.
I am able to connect to and browse the shared folders on the server using Windows Explorer, so it is not a physical connection issue. I can ping other machines on the network from the server, but trying to ping the server from another machine results in "Destination host unreachable".
As far as I can tell, the server refuses any TCP connections from any machine. I am thinking, there must be some other configuration setting that I am missing... Please, help.
NS
Like in Windows 7 the behaviour is determined by the network type (home, work, internet) the OS thinks it is connected to... even with a disabled firewall it respects these settings and accordingly refuses/allows connections...
The solution is embarrassignly simple, and the credit goes to Ashley Steel, on ServerFault.com for asking just the right questions. It turns out that the DNS was resolving the name of the server incorrectly, because the machine was named the same as an old, since decommissioned workstation that used to live on the same subnet.
The solution: rename the server.
NS[Now hiding under a rock]

Why can't I make an http request to the ASP.NET development server on localhost?

I have an ASP.NET project (VS2008 on Windows 7 with either webforms, MVC1, or MVC2 -- all the same result for me) which is just the File->New hello world web project. It's using the default ASP.NET development server, and when I start the server with F5, the browser never connects and I get a timeout. I tried to debug this by telnetting to the development server's port while it was running, and I got the same result:
C:\Users\farmercs>telnet localhost 54752
Connecting To localhost...Could not open connection to the host, on port 54752:
Connect failed
I can see in the system tray that the server thinks it's running, and a netstat -a -n command shows that there is indeed an active TCP listener on that port.
This worked in the not-too-distant past, and I could work on web projects using the development server. One thing that has changed since then was that I installed the Microsoft Loopback Adapter to accommodate a local development Oracle installation. I'm not sure this is the problem, but it seems a likely culprit.
I also tried to hit the port using the server name itself (http://mycomputername:54752) but with the same result.
So, what could be blocking me from connecting? And if it's the loopback, then what is a good way for me to retain my ability to connect to my development Oracle server while still being able to use the ASP.NET development server?
have you checked your host file?
%SystemRoot%\windows\system32\drivers\etc\host
look if there is any redirection of localhost or 127.0.0.1 to somewhere else rather than your pc

trouble hosting asp.net on iis

I'm doing some test hosting of an asp.net program I created
I can access it fine from the local machine (both debugging and pointing the virtual directory to it)
I can also access (local) by using the localhost or using the ip
however when i get on a different machine on the same network (i can ping my machine)
I get the following error:
Connection Interrupted
The connection to the server was reset while the page was loading.
The network link was interrupted while negotiating a connection. Please try again.
Does anyone have any idea what I'm doing wrong?
Crash893
EDIT:
I have duplicate this question on serverfault.com
I would generally take a snapshot of the network traffic with Wireshark (or other network sniffer) and see what is happening on the wire. Compare this to a site that works. Windows firewall, a browser proxy, or some other network software may be at fault.

Resources