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

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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19 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 ...
6
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1answer
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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18 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, ...
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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
69 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
142 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
48 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 ...
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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
71 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
38 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
49 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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13answers
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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 ...
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1answer
56 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
57 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
42 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
40 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 ...
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4answers
4k 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
22 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 ...
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2answers
117 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 ...
44
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6answers
264k 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?
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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 ...
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1answer
26 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 ...
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0answers
91 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). ...
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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: ...
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0answers
50 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
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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 ...
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2answers
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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
900 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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33 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 ...
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1answer
89 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 ...
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1answer
30 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 ...
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3answers
2k 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 ...
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3answers
858 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 ...
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1answer
282 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 ...
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0answers
78 views

Network speed between Windows 7 machines sharing over samba/SMB not reaching 10Gb/s

I have two Windows 7 Machines that are connected via 10Gb/s Intel Server Cards on a 10Gb/s Switch an a subnetwork(Physically separate from the larger main domain network). I'm trying to copy files ...
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1answer
5k views

ping -a sometimes returns host name and sometimes returns FQDN. Why? Does this mean DNS is corrupt somehow?

I have a Windows machine called abcd for example and it uses DHCP to receive an IP address (172.28.45.5 for example) When I perform ping -a 172.28.45.5 sometimes I receive abcd as the hostname. ...
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2answers
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How do I set up IP over FC?

I have 2 systems, with a Broadcom BCM5701 and a LSI7202p, of which are connected with a LC->SC cable. The cards are properly detected in Linux, however I wish to set up IP over FC. I've read online ...
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5answers
2k views

What ports are least likely to be probed on the internet? [closed]

Suppose you've got a server that runs insecure software and you have to make it publicly accessible, what ports are "safest" for providing that service on the internet. By "safest" I mean least likely ...
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0answers
41 views

Many TCP retransmissions with NAT interface in VMware Workstation

I have a problem with TCP retransmissions between outside servers and a virtual machine in VMware Workstation 12 that is configured with a NAT interface (vmnet8). To simulate a slow link, I have set ...
6
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5answers
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Tunnel over UDP or TCP

Is there a way to create something similar to an IPIP or GRE tunnel only over UDP or TCP? I have a GRE tunnel between two servers and I noticed that sometimes it starts to drop packets. At the same ...
0
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1answer
63 views

Can't communicate out of VM instance for Modbus TCP/IP over port 8080 - routes poosibly required

I have used Google Cloud Developers Console to set up a Windows 2012 Server. I am trying to use this a web server for monitoring hardware utilising Modbus TCP/IP. I have installed a SCADA software ...
2
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2answers
765 views

How to cap network traffic using TCP/IP settings in Windows 7?

Is it possible to cap network traffic on a Windows 7 system so that it will not exceed a given throughput value? The BitTorrent client uTorrent is able to do this, but I am guessing that it's doing ...
2
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2answers
87 views

Random three minute delay for database server connect

we use InterBase on a Windows 2003 server, and in random intervals the client connection to the server takes 180 seconds (three minute) longer than usual. The application does not "hang" with the ...
0
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1answer
150 views

How many data channel ports do I need for an FTPS server running behind NAT?

As the title states, I currently have an FTP server accessible via FTP or FTPS (explicit) running NATed behind a router. The server is running Windows Server 2012 R2 with IIS 8.0 (I believe that is ...
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1answer
159 views

Millions of TCP FIN-ACK retransmissions blocking traffic on my desktop machine

In a few minutes I have received about 7 millions(!) FIN-ACK packets from IP address that belongs to Google 74.125.133.188 what totally blocked network traffic on my desktop(!) machine. Other ...
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2answers
418 views

IP on different subnet mask [closed]

I'm still learning the ropes of Windows Server (specifically 2012R2). My assigned task is to setup a static local IP address, I managed to get it set to 192.168.1.96 (with subnet mask 255.255.255.0) ...
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5answers
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how to make standard ssh port a stealth port?

I'm running a personal ssh server on a nonstandard port. If someone tries to log into my ssh server thru the standard port 22, it seems that the server sends "Connection refused" message. $ ssh ...
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1answer
123 views

Static ip addressed hardware unreachable

I need help, I have multiple things (NAS box's and the like) on a static 10.10.10.x network. My new situation forced me to use an Air Card on one laptop and using Internet connection sharing to allow ...
2
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2answers
426 views

TCP sequence number randomization

In a recent interview, my friend was asked about firewalls’ TCP sequence number randomization feature. The interviewer mentioned that we know that a firewall randomizes the TCP sequence number, but an ...