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Questions tagged [tcpip]

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"

464 questions
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Multiple IP addresses per NIC

How can I have multiple IP addresses assigned to a single NIC? I remember doing this on Unix way back when. Can it be done on Windows?
BIBD
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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: -A INPUT -p tcp -m tcp --dport 22 -j DROP -A INPUT…
user3125731
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Diagnosing packet loss / high latency in Ubuntu

We have a Linux box (Ubuntu 12.04) running Nginx (1.5.2), which acts as a reverse proxy/load balancer to some Tornado and Apache hosts. The upstream servers are physically and logically close (same DC, sometimes same-rack) and show sub-millisecond…
Sam Gammon
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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) machine, no TIME_WAIT is listed by netstat -an on…
mgd
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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 know that TIME_WAIT consumes file descriptors? or…
sam
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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 client IP address would not require modification. So…
Geoff Dalgas
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Answering on the same interface where the request came from

First, I know this is not how IP is intended. But as usual, this is how I need to have it working. I work for a security company. There are at least 2 network interfaces. Both interfaces should have a default gateway. One interface is a default…
Malic
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Windows 7 TCP Listen Ports

My fresh install of Windows 7 shows 5 programs listening on TCP ephermeral ports: TCP 0.0.0.0:49152 0.0.0.0:0 LISTENING TCP 0.0.0.0:49153 0.0.0.0:0 LISTENING TCP 0.0.0.0:49154 …
None
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limits.conf setting doesn't 'stick'

Trying to get the equivalent of ulimit -n 20000 on a high load web server, however the /etc/security/limits.conf on ubuntu hardy doesn't seem to stick. here is what I set in the config file. root soft nofile 20000 root …
Brandon Helwig
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Running lsof -i shows a lot of connections in CLOSE_WAIT ? Should I worry

So I am running lsof -i | wc -l periodically and it is telling me that out of 420 lines, between 240 and 255 are in CLOSE_WAIT state. How does TCP connections enter this state? Should I be worried and how should I troubleshoot it?
user20414
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HTTP, TCP, UDP and connectionless

I am a bit confused with HTTP lately. Some facts are that TCP can operate connection orientated or connectionless, this I understand. TCP though is connection-oriented while UDP is connectionless which is used when the message itself can fit…
What'sTheStoryWishBone
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Unencrypted equivalent of SSH reverse proxy

I'm looking for an equivalent of this: ssh -R 8888:10.0.0.2:8888 100.101.102.103 ie. make the service running on port 8888 on the local machine (10.0.0.2) look like a locally running service on a remote machine (100.101.102.103). However, I don't…
user9626
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Serial port forwarding over TCP/IP (linux server)

I am looking for a way to use a remote serial port on a linux machine over LAN. The machine is running ubuntu 10.04 and I have a arduino board connected to it, that I would like to be able to reprogram or listen/talk to serial output of it over LAN.…
Kamil Zadora
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Can I make TCP/IP session to run less than 60 seconds?

Our server is overloaded with TCP/IP sessions, we have 1200 - 1500 of them. Most of them are hanging in TIME_OUT state. It turns out that a connection in TIME_OUT state occupies a socket until 60 second time-out is elapsed. The problem is that the…
par
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Windows 7 Client flooding network with DHCP requests. Not setting IP

I have a small network, with 15 workstations, SAMBA AD, and a bunch of Virtualized linux servers. All the workstations, and servers are on the same subnet. All workstations are running Windows 7 Pro Both my Samba 4 DC, and ISC-DHCP-SERVER are…
Skye Bowen
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