Tcp test

There are several link integrity tests available: Ping Test TCP Connection Test DNS Lookup Test Device Cloud Connection Test You can use these tests to demonstrate that two-way communication is working over the mobile connection. Several tests are provided because different mobile networks or firewalls may allow or block Internet packets for various services. Select the appropriate test according to the mobile network constraints and your preferences. The link integrity tests are only performed while the mobile connection is established. If the mobile connection is disconnected, the link integrity tests are suspended until the connection is established again. For the link integrity tests to provide meaningful results, the remote or target hosts must be accessible over the mobile connection and not through the LAN interface of the device (if it has one). That is, you should configure the settings to guarantee that the mobile connection is actually being tested. You can modify the link integrity test settings at any time. These changes go into effect at the start of the next test interval. Ping Test Enables or disables the use of “ping” (ICMP) as a test to verify the integrity of the mobile connection. The test is successful if a valid ping reply is received in response to the ping request sent. The ping test sends 1 ping request and waits up to 30 pings for a reply. When a valid reply is received, the test completes successfully and immediately. You can configure destination hosts for this test. If the first host fails to reply to the ping request, the same test is attempted to the second host. If neither host replies to any of the ping requests sent, the test fails. The primary and secondary addresses may be either IP addresses or fully qualified domain names. Primary Address: First host to test. Secondary Address: Second host to test if the first host fails. TCP Connection Test Enables or disables the creation of a new TCP connection as a test to verify the integrity of the mobile connection. A successful test establishes a TCP connection to a specified remote host and port number. If the remote host actively refuses the connection request, the test fails. The TCP connection test waits up to 30 seconds for the connection to be established or refused. When the TCP connection is established, the test completes successfully, and the TCP connection is closed immediately. You can configure two destination hosts for this test. If the first host fails to establish (or refuse) the TCP connection, the same test is attempted to the second host. If neither host successfully establishes (or refuses) the TCP connection, the test fails. The primary and secondary addresses may be either

Use this to test port 9001 on IP address 10.20.30.40:nc -z -v -u 10.20.30.40 9001When the connection is successful, the screen output is:Connection to 10.20.30.40 9001 port [udp/*] succeeded!TCPTo use netcat for checking a TCP connection, you can use this to test port 9001 on IP address 10.20.30.40:nc -z -v 10.20.30.40 9001When the connection is successful, the screen output is:Connection to 192.168.168.121 9001 port [tcp/*] succeeded!WindowsUDPTo use PortQry.exe for checking a UDP connection, you can use this to test port 9001 on IP address 10.20.30.40:portqry -n 10.20.30.40 -e 9001 -p UDPWhen the connection is successful, the screen output is:UDP port 9001 (unknown service): LISTENING or FILTEREDIn the PowerShell session, you can also see if the connection was successful. It will show you a PortQry Test Message:10.20.30.40:61199 PortQry Test MessageTCPTo use PortQry.exe for checking a TCP connection, you can use this to test port 9001 on IP address 10.20.30.40:portqry -n 10.20.30.40 -e 9001 -p TCPWhen the connection is successful, the screen output is:TCP port 9001 (unknown service): LISTENING The scriptBelow is the script. You can save it on the system you want to start a TCP or UDP listener.function New-Portlistener { [CmdletBinding(DefaultParameterSetName = 'All')] param ( [parameter(Mandatory = $false, HelpMessage = "Enter the tcp port you want to use to listen on, for example 3389", parameterSetName = "TCP")] [ValidatePattern('^[0-9]+$')] [ValidateRange(0, 65535)] [int]$TCPPort, [parameter(Mandatory = $false, HelpMessage = "Enter the udp port you want to use to listen on, for example 3389", parameterSetName = "UDP")] [ValidatePattern('^[0-9]+$')] [ValidateRange(0, 65535)] [int]$UDPPort ) #Test if TCP port is already listening port before starting listener if ($TCPPort) { $Global:ProgressPreference = 'SilentlyContinue' #Hide GUI output $testtcpport = Test-NetConnection -ComputerName localhost -Port $TCPPort -WarningAction SilentlyContinue -ErrorAction Stop if ($testtcpport.TcpTestSucceeded -ne $True) { Write-Host ("TCP port {0} is available, continuing..." -f $TCPPort) -ForegroundColor Green } else { Write-Warning ("TCP Port {0} is already listening, aborting..." -f $TCPPort) return } #Start TCP Server #Used procedure from $ipendpoint = new-object System.Net.IPEndPoint([ipaddress]::any, $TCPPort) $listener = new-object System.Net.Sockets.TcpListener $ipendpoint $listener.start() Write-Host ("Now listening on TCP port {0}, press Escape to stop listening" -f $TCPPort) -ForegroundColor Green while ( $true ) { if ($host.ui.RawUi.KeyAvailable)

UPS on it. #5 from cms switch connections administration and troubleshooting manual:Troubleshooting a TCP/IP linkTCP/IP link troubleshooting can be done at the switch and at the CMS computer. This section describes tests you can run from either system.Switch testsUsing the system administration terminal on the switch, you can use the following commands to test the TCP/IP link: ping ip-address X.X.X.X board CCs [packet-length YYYYrepeat ZZZ] (where X.X.X.X is the IP address of the CMS computer, CCs is the equipment location of the C-LAN circuit pack, YYYY is the size of the test packet, and ZZZ is the number of times the test will be repeated)The packet length and repeat options are available with DEFINITY R8 or later. This command sends a test message to the specified IP address to request a remote echo. The results will be either pass or fail, and will show how long the test took to complete. The packet length defaults to64 bytes, with a maximum of 1500 bytes. ping node-name XXX board CCs [packet-length YYYYrepeat ZZZ] (where XXX is the node name of the CMS computer,CCs is the equipment location of the C-LAN circuit pack, YYYY is the size of the test packet, and ZZZ is the number of times the test will be repeated)The packet length and repeat options are available with DEFINITY R8 or later. This command sends a test message to the specified node name to request a remote echo. The results will be either pass or fail, and will show how long the test took to complete. The packet length defaults to 64 bytes, with a maximum of 1500 bytes. netstat ip-routeThis command displays the destination IP address, gateway IPaddress, C-LAN circuit pack used for the route, and the interface for the route. status processor-channels X (where X is the processorchannel used for the TCP/IP link)This command displays the current status of the processor channel used for the TCP/IP link, and the last time and reason that the channel went down. status link X (where X is the TCP/IP link number)This command displays the status for the TCP/IP link. Page 1

I have an hmail server configured and I know that comcast blacks port 25. I have setup a dynu service for relay and port 25 redirect. Port 2525, 25 465 587 110 143 are opened on my router and pointed to the IP of the mail server. I have gone to No_IP.com and edited mx to use the mx1.dynu and mx2.dynu.com entries..here is a dump of my Hserver diagnostic window:Test: Collect server detailshMailServer version: hMailServer 5.6.7-B2425Database type: MSSQL CompactTest: Test IPv6IPv6 support is available in operating system.Test: Test outbound portSMTP relayer is in use.Trying to connect to host relay.dynu.com...Trying to connect to TCP/IP address 168.235.105.136 on port 587.Received: 220 relay.dynu.com ESMTP.Connected successfully.Test: Test backup directoryBackup directory C:\mailback is writable.Test: Test MX recordsTrying to resolve MX records for dktucsonmail.ddns.net...Host name found: mx1.dynu.comHost name found: mx2.dynu.comTest: Test local connectConnecting to TCP/IP address in MX records for local domain domain dktucsonmail.ddns.net...Trying to connect to host mx1.dynu.com...Trying to connect to TCP/IP address 207.38.69.195 on port 25.ERROR: It was not possible to connect.Trying to connect to host mx2.dynu.com...Trying to connect to TCP/IP address 107.161.27.201 on port 25.ERROR: It was not possible to connect.ERROR: Was not able to open connection.Test: Test message file locationsRelative message paths are stored in the database for all messages.Test: Test IP range configurationNo problems were found in the IP range configuration.

Using less memoryConversely, if the proxy inspection is mandatory, consider changing the tcp window to dynamic.Disable NP offloading:On the new test firewall policy from above disable NP offloading functionality.This can help in cases where an NP may be faulty or encounter aberrant traffic.See this article for instructions. Then re-test.Check bandwidth availability.This is especially important for traffic traversing the internet.Check that the internet service at both ends of the connection is not saturated for both ingress and egress traffic.The best way to do this is likely by reviewing logs or running a report based on log data.Also, under FortiView -> Policies/Sources/Destinations there is some bandwidth information available.Example:If traffic is saturated, consider implementing a guaranteed traffic shaper for the traffic in question.Isolate from the internal network.In extreme cases, it may be beneficial to connect a test client and server directly to spare firewall ports and re-test after creating appropriate policies.Impact of Latency on TCP Download Performance. TCP is a reliable protocol for sending data accurately and in order, but its performance is affected by latency.The higher the round-trip time (RTT), the lower the TCP download throughput will be, even if the connection speed is high. For example, with a 1 Gbps link, the maximum possible throughput might only be 17.4 Mbps if the latency is 30 ms. This shows how TCP performance can be significantly constrained by latency.To estimate the maximum theoretical throughput of a TCP session, the following formula can be used: Throughput = TCP maximum receive windowsize / RTTThis ensures