analysis tool for statistics about active connections, open sockets, routing tables; in general the networking subsystem.

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10
votes
4answers
8k views

What's the easiest way to find an unused local port?

What's the easiest way to find an unused local port? Currently I'm using something similar to this: port=$RANDOM quit=0 while [ "$quit" -ne 1 ]; do netstat -a | grep $port >> /dev/null if ...
10
votes
5answers
8k views

Under AIX, how can I get the full path of a program bound to a port?

Under Linux I can use netstat -tulpnw and ps, like so: # netstat -tulpnw | grep :53 tcp 0 0 127.0.0.1:53 0.0.0.0:* LISTEN 1482/named udp ...
9
votes
4answers
14k views

How to check that a daemon is listening on what interface?

Ex.: an sshd is configured to only listen on wlan0. So. Besides checking the sshd_config how can I check that a daemon is listening on what inerface? netstat can do it? how? (OS: openwrt or scientific ...
7
votes
4answers
34k views

How do I know what service is running on a particular port in linux?

I am trying to run weblogic server on my linux machine and I am getting the following error : ERROR: transport error 202: bind failed: Address already in use ERROR: JDWP Transport dt_socket failed to ...
7
votes
4answers
11k views

Logging outgoing connections as they happen

Is there a way to log to file all the outgoing connections that a process creates? I am aware of netstat but that seems to be more of a snapshot of a point in time rather than something that runs and ...
6
votes
2answers
25k views

Finding the PID of the process using a specific port?

I am installing hadoop on my Ubuntu system. When I start it, it reports that port 9000 is busy. I used netstat -nlp|grep 9000 to see if such a port exists and I got this: tcp 0 0 ...
5
votes
3answers
1k views

How can I know the process name which is opening a tcp port?

I have two linux servers. Let's say they are C and S. C is client of S On my S machine, I type. $ netstat -an | grep ESTABLISHED tcp 0 0 192.168.1.220:3306 C:57010 ...
5
votes
5answers
4k views

meaning of Netstat local address column

Local address on netstat output: When I do netstat -ntlp there is a column called Local Address: sometimes it would output IP address as 0.0.0.0:7180 and sometimes 127.0.0.1:9001 What's the ...
4
votes
4answers
8k views

How to do an IF statement from the result of a executed command

I am trying to do an IF statement from the output of an executed commmand. Here is how I am trying to do it, but it doesn't work. Does anyone know the right way to do this? if [ "`netstat -lnp | ...
4
votes
3answers
4k views

Source code of netstat

Can I view the source code of netstat on my Linux machine?
4
votes
2answers
172 views

Find which ports a program access

I have a program that tries to connect to a server on start-up on a unknown port. I need to find out which port the program accesses to enable a ssh tunnel. I tried netstat but since the connection ...
4
votes
3answers
579 views

Command similar to netstat -np but grouped by state and PID?

Is there a command similar to netstat -np but grouped by state and PID? I'd like to know the current count of server connections in a particular state grouped by Programs. similar to, 102 squid ...
4
votes
3answers
5k views

How to list all unique ip address currently connected to a specific port?

Say I want to know how many unique clients are connected to port 5222 on a server. Can you find a way better/faster/stronger than this? netstat -nt | grep ':5222.*ESTABLISHED' | awk '{ print $5 }' \ ...
4
votes
0answers
78 views

chromium browser (pepperflashplugin) opening listening ports on 0.0.0.0:5353

I am using chromium browser (chrome) with pepperflashplugin in Debian. I have noticed, chromium/pepperflashplugin opens a listening port on my public interface 0.0.0.0:5353 as seen with netstat: ...
3
votes
2answers
2k views

Why does SSH show protocol as tcp6 *and* tcp in netstat?

$ netstat -nat Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 0.0.0.0:80 ...
3
votes
1answer
37 views

log PID of each connection attempt

Finding the PID of an established connection is trivial using netstat or lsof. However, I have a process which is creating a connection ever 60 seconds to our database and locking it up by maxing out ...
3
votes
1answer
158 views

How does netstat command fit in various layers of TCP/IP model in the performance diagram?

netstat command is useful to, Print network connections, routing tables, interface statistics, masquerade connections, and multicast memberships. Now, I was reading about the Linux performance ...
3
votes
1answer
827 views

why ss(8) understands listening UDP ports differently than netstat(8)?

If I execute ss -lu in order to view all the listening UDP sockets, then none of the sockets are displayed. If I execute ss -au, which lists all(both listening and non-listening) UDP sockets, then ...
3
votes
1answer
126 views

Tons of unknown connections in nethogs

I am seeing hundreds of different connections to the same ip and port scrolling by when running nethogs. Occasionally the foreign IP and port will change (not always 80, but sometimes). I've noticed ...
3
votes
1answer
2k views

Accounting for /proc/net/dev reported traffic

I noticed that according to /proc/net/dev I am constantly receiving around 6Kb/s on my wireless usb interface. But I can't account for anything even close to that with the individual connections that ...
2
votes
2answers
3k views

What does 0.0.0.0:* mean in netstat?

Could anyone explain the following output of netstat -plunt? udp 0 0 0.0.0.0:58262 **0.0.0.0:*** 1163/avahi-daemon: udp 0 0 0.0.0.0:17500 ...
2
votes
2answers
1k views

Per Socket network Buffer queues utilization

Is there a way to get a per-socket send and receive Queues utilization on Solaris similar to the way that Linux' netstat displays it? Example on Linux: Proto Recv-Q Send-Q Local Address ...
2
votes
1answer
131 views

Why is the 'foreign address' not IP address but something like this?

I never learned network programming and this kind of stuff properly. Only know very basic stuff like IP address and just a vague concept of what ports and TCP/IP are. Here, I connected to my lab's ...
2
votes
3answers
5k views

tcp6 in the output netstat

What does column 'tcp6' mean on output netstat? Please anyone explain the follow output of netstat: tcp6 0 0 dmz.local.net:www 5.140.235.6%14631:49964 ESTABLISHED 21393/apache2 What does tcp6 mean? ...
2
votes
1answer
28 views

How to report receive queue size for AF_UNIX sockets

netstat -a reports Recv-Q (amount of unread data pending for a reading application) for AF_INET sockets, but not AF_UNIX sockets (at least not for SOCK_DGRAM). Does anybody know a way to obtain this ...
2
votes
2answers
2k views

netstat — why are IPv4 daemons listening to ports listed only in -A inet6?

I have a computer with: Linux superhost 3.2.0-4-amd64 #1 SMP Debian 3.2.60-1+deb7u3 x86_64 GNU/Linux It runs Apache on port 80 on all interfaces, and it does not show up in netstat -planA inet, ...
2
votes
1answer
844 views

Understand netstat -i flgs

Can anyone explain for me what each option in Flg means? [root@apple ~]# netstat -i Kernel Interface table Iface MTU Met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg eth0 ...
2
votes
2answers
3k views

Open a port in my CentOS

I'm trying top open a port on my CentOS machine: I edit the /etc/sysconfig/iptables file and add my rule: -A INPUT -p TCP -m state --state NEW -m tcp --dport 143 -j ACCEPT Then I restart the ...
2
votes
3answers
486 views

VPN and gateway problems

I've got a corporate VPN, which I use to access the Internet. When it's on, I cannot reach the servers inside the corporate network anymore, so I think there are some problems with the gateway setup. ...
2
votes
2answers
180 views

netstat command doesnt work anymore on the new dedicated server

I was using the following command on my previous dedicated server with the same version of the FreeBSD installation: # uname -a FreeBSD 9.2-RELEASE FreeBSD 9.2-RELEASE #0 r255898: Thu Sep 26 22:50:31 ...
2
votes
2answers
88 views

OS X: how to keep the computer from sleeping during a http connection

An application I use downloads data from a specific server, and I need it to sleep after the download has finished and the socket is closed. However downloads take place at random days, the app that ...
2
votes
0answers
67 views

How do I find out how long a socket is in CLOSE_WAIT?

I have a server relatively with a high number of sockets in CLOSE_WAIT I want to know the age of each socket, to know if it's a real problem (sockets not getting closed) or that the sockets are ...
1
vote
3answers
253 views

How can I identify processes that use network facilities, and can they be killed?

In the output of netstat -a | grep LISTEN there are usually a lot of processes. How (where) can I find out information about them, what is their purpose in the system and if I can kill them? Which ...
1
vote
3answers
89 views

Status of network ports

I hope it is possible to get the necessary details of each network port from /etc/services. If I have to develop a C++ program to get the status of each port how should I start it? I am not allowed ...
1
vote
2answers
865 views

How to use netstat command

My question is what does it mean to LISTEN or ACCEPT on a port as it relates to my example? Example: I have a tomcat server, and It will use port 8080. I want to make sure that port is available for ...
1
vote
1answer
58 views

ss is replacing netstat, how can I get it to list ports similarly to what I am used to?

I've been trying to modernise my way with Linux by, for one thing, ditching netstat for ss. I looked up my favourite command line flag for netstat in the ss man pages, and was very glad to find that ...
1
vote
1answer
197 views

How to do a netstat that will only filter based on pid

How can I have the following command below just show/filter based on the PID's I'm looking for? sudo netstat -lp --inet The results come back as this Proto Recv-Q Send-Q Local Address ...
1
vote
1answer
3k views

netstat shows an ESTABLISHED connection with no process

I am debugging some problems with postfix. When I establish a connection nothing happens and netstat shows: $ netstat -anp ... tcp 0 0 129.132.202.106:25 129.132.179.232:60154 ...
1
vote
2answers
144 views

what is 'smakynet' in the netstat result?

after logging into a server, I used netstat to check out the ports of this server and wanted to find which port was communicating with me My IP is 143.248.143.198 and my search results are like ...
1
vote
1answer
959 views

Iptables rule to allow only one port and block others

We have two apps running (on top of linux) and both communicates through port 42605. I wanted to quickly verify if this is the only port that's been used for communication between them. I tried below ...
1
vote
1answer
730 views

Have netstat not display port numbers for foreign address

I would like to get netstat to not display port numbers on the foreign address so I can run some statistics on it. This is for a FreeBSD system. The following is a example of the output. ...
1
vote
0answers
14 views

Count all network requests to a specific host

I have a mock server running on my localhost that mocks out a back end service that I need for my app. One thing that I want to do is count the number of requests [GET, POST, PUT, DELETE,...] that my ...
1
vote
0answers
31 views

How can I log outgoing TCP traffic including the full path of URLs?

I use a program regularly on Linux that makes a TCP request when it starts up and updates a file with an access token before launching. I'd like to write a batch script that makes this request (using ...
1
vote
0answers
139 views

Command for finding open ports

On my linux servers I have this alias set: alias ns="sudo lsof -Pi|grep -v ESTABL|grep -v CLOSED|grep -v -e '->' | tr -s ' ' '\t' | awk '{print $3 "\t" $8 "\t" $5 "\t" $9 "\t" $1}'| column ...
1
vote
1answer
768 views

Netstat shows programs running on different ports then they should

I have some code I'm testing. Program A listens on a predefined socket for program B to connect to and for my testing I'm running 32 instances of the programs A and B. I've written my script to tell ...
1
vote
0answers
273 views

Information about the 1630/master app

When I run $ sudo netstat -a --programs | grep LISTENING | grep 1630 I will get this output. Do you know what good are processes running under this app name? Why they I running on my system and if ...
0
votes
2answers
307 views

Where are netstat's -t and -u flags documented?

I use the following command to find open ports on my servers: $ netstat -ntulp I've probably found that on some random website over the years. However, I cannot find where -t or -u are documented. ...
0
votes
2answers
2k views

How to determine eth0 gateway address when it is not the default gateway?

In my system I have eth0 (which may or may not be connected) and a modem on ppp0 (which always may be up or down). The the case where both interfaces are up and ppp0 is the default route, I'd like to ...
0
votes
2answers
170 views

what process is listening on a given port

I have several problems: some process is attempting to send data and the firewall is rejecting it at the rate it is sending it out firewall logs flood the system (may need to rate-limit the logging) ...
0
votes
1answer
31 views

Why can `lsof -i` not show an open connection which `netstat -n` lists?

A strange situation. I started telnet 0 8081 and lsof -i (run under root) doesn't list this connection, but netstat -n does. Why can this be?