TCP and IP are two important protocols used in networking today. Due to their importance, the Internet Protocol Suite is also commonly known as "TCP/IP"

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Communication between two PCs [closed]

I need to make two PCs communicate using Ethernet connection. I am quite new to the field. I want to know what mechanism would be the best; Client-server, P2P, Uni-cast or multi-cast. Or the later two ...
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1answer
1k views

Multiple Homed Windows 2008 Server / Windows 7 Client

I have a small Windows 2008 network, with some Windows 7 clients. The clients are both laptops with docking stations and I would like them to communicate with the Windows 2008 server (for filesharing) ...
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2answers
1k views

Where are my TIME_WAITs on Mac OS X?

No TIME_WAITs on Mac OS X Normally, when a TCP connection is closed, the socket on the side where close() is called first is left in the TIME_WAIT state. When one of the peers is a Mac OS X (Lion) ...
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52 views

Windows 7 suppression of tcpip event 4199

I've noticed that Windows 7 doesn't raise event 4199 (Duplicate IP on network) consistently when assigning static IP addresses to machines. If we configure 2 machines correctly with non-conflicting ...
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1answer
36 views

TcpTimedWaitDelay is missing in Windows Server 2012

Suddenly my server log shows: An operation on a socket could not be performed because the system lacked sufficient buffer space or because a queue was full And I googled and found these links as ...
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0answers
31 views

No Network Traffic Between Host and VM

I have a virtual machine running that I wish to connect to a physical piece of hardware via an Ethernet connection from the host machine. This piece of hardware requires a specific IP address to be ...
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2answers
454 views

TCP timeout for established connections in Windows

I have the following situation: Application (Firebird DB client) on a client computer opens a TCP connection to server on port 3050 Application crash on client, application terminated netstat on the ...
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0answers
20 views

How to increase TCP window Size

I have a wire shark capture where SYNC happens between two nodes and when Receiver B send ACK to A with Window size =260( Actual expected 64K) after which i get a reset and again communication starts ...
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1answer
43 views

Windows server 2008 R2(standard) client connection is very slow after connecting above 24 client machines? Is there any client connection limit?

Windows server 2008 r2 standard is connecting 24 cilent machines after while adding extra machines to server it gets slow. In Windows server 2008 r2 maintaining the mysql database and all other client ...
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1answer
87 views

Connection SSH port 22 via domain name but not public ip address

I have a Draytek router configured to port forward SSH connections to an internal server from specific ip addresses only. Clients and myself can connect externally successfully except one who cannot ...
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5answers
8k views

How is the MTU is 65535 in UDP but ethernet does not allow frame size more than 1500 bytes

I am using a fast ethernet of 100 Mbps, whose frame size is less than 1500 bytes (1472 bytes for payload as per my textbook). In that, I was able to send and receive a UDP packet of message size 65507 ...
8
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2answers
1k views

How to configure iptables so an unwanted port is not reported as filtered

I'd like to stop others from seeing my ports as filtered in the nmap standard scan (unprivileged). Let's say that I have the following ports open: 22, 3306, 995 and a firewall configured like this: ...
4
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2answers
1k views

TIME_WAIT consumes file descriptors?

In many TCPIP and Web tunning guide, recommends increasing max number of file descriptors when getting the error "Too many open files" but, i can't see TIME_WAIT in outputs of "lsof -i" Does anyone ...
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1answer
37 views

what are the implications of running a FQDN as internal AD domain and point A-record for website to different host?

The MSP for a law firm office that has just joined our company is using a FQDN as an internal AD Domain and has been doing so for sometime apparently. They have this issue in that they have a website ...
1
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1answer
51 views

Ephemeral port reuse for TCP connections to different IP addresses

I know that a web server running a website on TCP port 80 can receive TCP connections from many different IP addresses sourced from many different ephemeral ports. Can a client initiate multiple ...
3
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2answers
6k views

IIS7 hundreds of connections in CLOSE_WAIT

I have a .Net application on my IIS7 server it was working fine until I had to move it to another server. I moved the exact same code to the new server and I noticed that after some hours the ...
40
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14answers
15k views

Why would you use IPv6 internally?

Of course, I realize the need to go to IPv6 out on the open Internet since we are running out of addresses, but I really don't understand why there is any need to use it on an internal network. I have ...
0
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1answer
80 views

Why does one of my LAN servers frequently require 21 seconds to connect?

Using a mix of Windows 7 and Windows 10 clients, one of my LAN servers tends to take 21 seconds to establish a connection. This LAN server is running Windows Server 2012-R2 and hosting TFS 2015 on ...
0
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1answer
23 views

Two subnets on one LAN

I have a simple 192.168.1.x/24 LAN GW & DNS = 192.168.1.254 My workstation is 192.168.1.101 I wish to setup a parallel mirror LAN for testing using a 192.168.10.x/24 subnet on the same switch. ...
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1answer
5k views

Good packet generator tool for IPv6.. Does hping3 support IPv6? [closed]

Does anyone of you know any good packet generator tool for IPv6. I am very familiar with hping3, but don't know if it supports IPv6. I am looking for something which can send, tcp, udp, icmp, and ...
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0answers
70 views

NLB cluster []: Timer starvation has been detected. This

we have two node NLB cluster basicly for http reguests. Server system logs have theese warnings: NLB cluster []: Timer starvation has been detected. This might be due to a denial of service attack or ...
0
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0answers
20 views

How to I diagnose downloads slowing over time?

I am trying to track down a strange networking problem. Basically, a http download from a tomcat server is slowing down over time. For example, the download speed starts at 700kb, then slows to 650, ...
3
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2answers
176 views

Not all printers are deployed on the client using Group Policy

Situation in our environment we are using the following servers to deploy printers in our domain forest: Windows Small Business Server 2008: contains the group policy to deploy the printers Windows ...
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2answers
159 views

What is the best IP subnet to avoid subnet collisions?

My company installs specialized webservers for tracking commercial building HVAC performance. These machines each have two LAN adapters--a primary and a secondary. The way the system is intended to ...
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1answer
51 views

How does a DNS forwarder build its cache?

I know that DNS forwarder cache is build up from responses by the authoritative name servers. But does it build its cache from the requests process by it? Let me explain what I mean. Lets say I have ...
3
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1answer
2k views

How to setup an TCP/IP proxy with traffic interception, for MS SQL traffic in this case

I would like to setup an MS SQL proxy server. It should forward all requests 1:1 and make it possible to log them, and modify some of the requests or answers according to some replacement rules I ...
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0answers
230 views

uWSGI TCP/IP host:port vs Unix socket

We are running a Python WSGI server (uWSGI) and changed to socket file instead of a tcp/ip localhost:port connection. Now our uwsgi logs are full of errors like IOError: write error SIGPIPE: writing ...
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1answer
44 views

Static IPs and New Domain Controller and Domain within existing Forest

I have a forest domain chicago.example.com that contains 2 domain controllers in it, in which I had joined a 2012 Server to the forest domain called DOMAINCONTROLLER3. I plan to promote this server to ...
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2answers
53 views

TCP/IP - why does routing without masquerading work?

I thought a data packet from another subnet is always rejected. But when I have two hosts (h1 and h2) in two different subnets (s1 and s2) and one router (r) with activated ip_forward and access to ...
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1answer
111 views

TCP connection not established: Can't Connect to MySQL Server on Remote Connection (10060)

I'm running MySQL 5.6 on a WinServer 2012 system. It works great. The server is on our office intranet, not accessible to the outside world. I normally administer MySQL remotely from my office on my ...
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2answers
73 views

Tracert not resolving IP

I know this is propably a basic question, i did some research on the net as to the whys and hows and got only more confused. I wanted to ask why tracert returns this : Tracing route to youtube.com ...
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2answers
43 views

A small puzzle about routing

This is a followup to this question I saw on SuperUser, to which no answer has been provided. A user deleted the second route in his routing table, # ip route show default via 192.168.73.1 dev ...
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0answers
65 views

Configure a websocket server in front of HAProxy

I have a small python server script which creates a websocket connection and accepts base64 encoded IP packets (very similar to this). As of now my script decodes the IP packet and sends it out into ...
15
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4answers
5k views

How are IP addresses actually assigned?

I'm having a hard time understanding how a governing body assigns IP addresses, companies use BGP to advertise those IPs, and how the internet works. Then, where the hell does DNS come in? Can ...
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0answers
25 views

Not getting TCP Update Window packet after TCP Zero Window begins

Once I get TCP Zero Window during data transmission, I can't send data anymore in that desktop sharing session. Even I stopped the data sending to check if it can resume but no benefit! In my test ...
48
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6answers
285k views

In Windows, using the command line, how do you check if a remote port is open?

What is a simple way in Windows to test if traffic gets through to a specific port on a remote machine?
9
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4answers
6k views

Dead gateway detection on Windows 2008 Server

We have recently implemented HAProxy for stackoverflow.com. We decided on using TProxy to maintain the source address for clients connecting so our logs and other IIS modules which depend on the ...
0
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1answer
28 views

Web application access permission

I have a web application that uses SQL server . SQL server is hosted on a server and accessed using port 1433 . My question is will the user who is accessing my application required to be able to ...
0
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0answers
117 views

Apache2 send [FIN, ACK] immediately

Currently we have an apache2 with mod_proxy in front of a tomcat7. What we have experienced is that some requests have been dropped by apache2 from time to time (i.e never been forwarded to tomcat7). ...
5
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2answers
3k views

Unable to increase the dynamic port range on Windows Server 2008

I'm trying to "tune" the TCP/IP stack on some Windows Server 2008 machines by following the instructions here: ...
2
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0answers
74 views

So many retransmission over NSX enabled vDS of vSphere

I'm currently on test of VMware NSX network environment and met some trouble. My Environment is: Management Cluster with 3 Hosts and NSX components on 2 dedicated Hosts Compute Cluster with ...
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2answers
54 views

Do Browsers implement the HTTP protocol?

My understanding of the TCP/IP stack is that the Application layer (layer 4) consists of protocol implementations such as HTTP. Do user-agents like web browsers implement this HTTP protocol ...
5
votes
2answers
879 views

How do I fake dropped packets (or actually make them fail)?

Background One of our clients suffers from an intermittant problem with their internet where it will drop packets when a user downloads a large file (their IT is looking into the problem). I have ...
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2answers
910 views

Big IP orphaned connections

Let me state up-front that I know just enough about networking at this level to be dangerous, so if I say something stupid, please be kind. I am using a Big IP load balancer in front of 3 Apache ...
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0answers
46 views

Corrupted files when downloading with HTTP

With my UMTS connection most archives > 50 MB are corrupted when downloading them via HTTP. If I switch to HTTPS the problem is gone. The problem should not reside in my network, because I have an ...
0
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1answer
205 views

Multiple IP Addresses from DHCP

I have a problem with multiple processes needing to bind a TCP socket to the same port in Windows Server 2008. At the moment I believe this is causing some unexpected erratic behavior as a race ...
0
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1answer
39 views

TCP/IP ack loss between firewall and server

Scenario: Client connects to Server using TCP/IP. Issue: During initial TCP/IP connection setup, the ACK packet [3rd step in TCP] sent from Client to Server has crossed the firewall [evidence from ...
0
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3answers
5k views

When to use routable vs non-routable IP addresses [closed]

As I understand it, there are several "non-routable" IP ranges: class A reserved space 10.0.0.0/8 class B reserved space 172.16.0.0/12 class C reserved space 192.168.0.0/16 class E reserved for ...
0
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3answers
872 views

Network device to change IP address within packets

I have an appliance with a class C IP address, for example 192.168.0.10. I can't or don't want to change this IP address. However when I connect this appliance to my network I want it to appear to ...
5
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1answer
346 views

How does stunnel redirect traffic?

I am familiar with the stunnel.conf and I know how to specify which unencrypted ports it listens to and to which encrypted ports it redirects, but I would like to understand how it gets the power to ...