netstat is a tool for viewing active network connections, listeners and sockets.

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1answer
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Concurrent connections per IP

I need to make a few changes to a firewall configuration, but before I do I'd like to see the number of concurrent Apache connections per IP. This command produces a nice list: #netstat -ntu | awk ...
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2answers
43 views

Print last column containing spaces and special characters

I need a full path/command thats been execued to start a process thats exposed on the network - listens on tcp/udp . I did manage to get all of that using below "one liner": netstat -nlp46|tail -n +3 ...
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0answers
20 views

Which flags should I use for my “netstat” commands? [migrated]

I would like to use two variants of the netstat command, one for exclusively IPv4 and the other for exclusively IPv6 traffic. For both commands I would only like to list the following information. ...
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1answer
2k views

UDP port appears to be in use but is not shown in netstat or TCPView

I've encountered some strange behavior I don't understand. I'm installing software on a Windows 2003 Server. This software needs to bind to a specific UDP port an all TCP addresses in order to listen ...
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2answers
1k views

How found suspect connection in a netstat output?

It seems some ssh brute force are outgoing from my debian 7.1. I'm searching how to find the source of these brute force. I'm searching in netstat output, but how can i identify trace of this hack ? ...
2
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1answer
811 views

iftop Shows Lots of Mysterious Connections - Not Showing in netstat

I've just stopped all pretty much all services except sshd on my server (Ubuntu Server 10.04), and when I run iftop I get output that looks like this: 12.5Kb 25.0Kb ...
2
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1answer
60 views

Is it normal to have many connections from my own server ip when I ran netstat command?

I would like to know if is it normal to have many connections from my own server ip when I ran: netstat -tn 2>/dev/null | grep :80 | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -nr | ...
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7answers
31k views

How do I get rid of sockets in FIN_WAIT1 state?

I have a port that is blocked by a process I needed to kill. (a little telnet daemon that crashed). The process was killed successfully but the port is still in a 'FIN_WAIT1' state. It doesn't come ...
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0answers
38 views

Why is SQL Server using all ephemeral ports connecting to itself and causing TIME_WAITs?

I've got an AWS server with Windows 2008 R2, SQL Server 2012, and Tomcat 7. When I run netstat -ano the screen is flooded with TIME_WAIT. I posted the output in a Gist. When I run CurrPorts, filter ...
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0answers
51 views

TCP High Send-q coupled with FIN_WAIT1 status

I'm having a problem with one of my webservers, which is taking minutes to completely render a web page. I had a look at the TCP connection and noticed that I have a very high value in the send-q ...
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0answers
47 views

No connection available in pool. netstat RecvQ shows high number

In our servers there is one particular dependency (java jar), which makes a total of 1024 connection to various remote servers (the library works as a service discovery). Intermittently, it is ...
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1answer
182 views

Nginx not running with no error message (ubuntu 14.04 lts)

I am trying to start my nginx server. When I type "$> /etc/init.d/nginx start", I have a message appearing "Starting nginx: Ok", and then nothing happens. When I type "sudo lsof -nP -i | grep ...
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2answers
214 views

How to make netstat on Linux only show OUTBOUND tcp connections?

My ubuntu server is infected and there is a process making a bunch of HTTP requests to a bunch of websites (sucks!). I have added the following to my firewall (UFW): sudo ufw deny out proto tcp to ...
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0answers
23 views

netstat output without PID

I just stumbled across this issue with the netstat output on my server, There are a couple of ports which are listening, but do not have a PID attached to it. I want to make sure they are not ...
1
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1answer
111 views

Port suddenly closed. How to re-open?

I've written a software module in PHP that manages the saving of data in different data stores (MySQL, ElasticSearch and Redis). To test the module, I've created several test plans in Apache JMeter, ...
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2answers
87 views

Limit to number of listening ports in linux

I have tried to launch a script to listen to thousands of tcp ports (1000 to 10000) but it appears to be hitting a limit of 1024 listening ports. I've confirmed this via netstat and closed ports above ...
1
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0answers
24 views

How to check a given connection has been offloaded to network card

From what I read, some part of the tcp protocol operation can be offloaded from kernel to network card driver thanks to TOE (or GSO, LSO, LRO..). My objective is too find if a given socket has some ...
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4answers
8k views

netstat shows many times deploy.akamaitechnologies.com connected to my server

Many times, after running netstat on my server, I find one of IP addresses belonging to deploy.akamaitechnologies.com connected to my server, do someone has an idea on what is happening on my server ? ...
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1answer
42 views

Simulation of TX/RX Drop

I'm trying to get the "TX/RX Drop" values to increase. I've tried dropping packets using both iperf and iptables but the statistics aren't increasing even when packets are being dropped. Is there a ...
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0answers
43 views

iptables traffic after forwarding

I have 2 servers Server A and Server B ServerA = 1.1.1.1 ServerB = 2.2.2.2 I am using ip-tables to send all traffic on port 80 to Server B on Server (A) 1.1.1.1 i have done iptables -t nat -A ...
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0answers
44 views

Ghost tcp connections: ss sees them, nothing else does

We have a strange problem. Our remote server shows over 900 connections coming from our office over port 80: # ss -n | grep ESTAB | grep $OFFICEIP | grep :80 | wc -l 935 Netstat shows a similar ...
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2answers
503 views

Netstat count TIME_WAIT connections by port

I can obtain individual TIME_WAIT counts on a port, netstat -nat | grep :11300 | grep TIME_WAIT | wc -l; but how to do this based on all ports eg: 11300 2900 connection 3306 1200 connection ...
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2answers
94 views

Display IP & TCP statistics per interface (netstat -s with interface)

Linux has the ability to display protocol statistics with netstat -s. The output looks something like: Excerpt: 7487 times unabled to send RST due to no memory TCPDSACKIgnoredOld: 817 ...
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1answer
121 views

Limit Number of TCP connections in Linux Server, to avoid attack

I want to limit the number of TCP connections in Linux server, I have used the following command. iptables -A INPUT -p tcp --syn --dport 80 -m connlimit --connlimit-above 25 --connlimit-mask 32 ...
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2answers
2k views

How does netstat get a hostname from IP while nslookup & nblookup fail every time?

In Windows Server 2003, when I run netstat with no flags, it takes much longer than netstat -n to return results. I realize this is because it has to perform reverse lookups by IP address to get the ...
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4answers
252 views

Is there a netstat -s equivalent for windows?

I know that netstat -s exists on Windows, but it displays way less informations than on Linux/OS X. It only gives 8 counters about TCP, while on Linux it's more than 50. I'm looking for any ...
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1answer
84 views

Port 80 doesn't work

I have a website in my ubuntu server 14.04, with apache2 server, and untils fews days go the site works fine but, today if I digit www.mydomain.com from my internal network it works but, if I try with ...
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5answers
164 views

Get number of TCP established connections

On a Linux server one can use netstat -tan | grep ESTABLISHED| wc -l but this will not work on a high load server with watch -n1. Such approach works fine if the server is not very busy or the ...
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1answer
126 views

What causes “SYN to LISTEN sockets dropped”?

A quite busy proxy server has lots of "SYNs to LISTEN sockets dropped". I learned one cause could be a too small backlog size. But in that case the "times the listen queue of a socket overflowed" ...
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0answers
61 views

xinetd stops working in Debian Wheezy

We have a server with a whois service running. The whois service is provided by xinetd. The configuration file /etc/xinetd.d/whois looks like this: service whois { socket_type = stream ...
18
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5answers
17k views

How to find other end of unix socket connection?

I have a process (dbus-daemon) which has many open connection over UNIX sockets. One of these connections is fd #36: =$ ps uw -p 23284 USER PID %CPU %MEM VSZ RSS TTY STAT START TIME ...
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1answer
79 views

What does it mean for netstat -t

I see the help of netstat -t option says Displays the current connection offload state. And I tried it in the windows command console. The Offload State value display InHost. What does Offload ...
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6answers
8k views

netstat shows a listening port with no pid but lsof does not

This question is similar to Network port open, but no process attached? I've tried everything from there, reviewed the logs, etc... and can't find anything. My netstat shows a TCP listening port and ...
0
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1answer
178 views

Netstat - Thunderbird and others work on strange ports

I'm getting this: $ sudo netstat -alpv tcp 0 0 comp.local:35409 ey-in-f16.1e100.n:imaps ESTABLISHED 2782/thunderbird-bi tcp 0 0 comp.local:52950 ...
79
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4answers
86k views

What's the difference between ip address 0.0.0.0 and 127.0.0.1?

I do know that 127.0.0.1 ~ 127.255.255.254 are the loopback IP addresses for most modern operating systems and we could use these IP addresses to refer to our own computer. But what's 0.0.0.0? It ...
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0answers
83 views

netstat e on windows shows really high bytes count

running netstat /e is giving me strange results "bytes received" from netstat /e output is always way higher, about 10 times higher than when netsh interface ip show subinterfaces is run. wireshark ...
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2answers
85 views

Difference Between Netstat and Access Log

When I was checking stats in SSH terminal for my VPS, I noticed that netstat and access log gives different results. When I used: netstat -anp I saw that one attacker having 32 concurrent ...
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0answers
2k views

Windows TCP Port 139 Netbios-ssn vulnerability

I ran netstat -b on my computer. Two results showed that I do not understand, VAIO being another PC on the LAN. [firefox.exe] TCP 192.168.100.106:49186 VAIO:netbios-ssn TIME_WAIT TCP ...
0
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1answer
61 views

there is empty ips in netstat

I have installed ddos deflate on my sever (centos6.5 64bit) and in server mailbox I see that ddos deflate has been blacklisted empty Ip. and when I run this command on ssh I see: netstat -ntu | awk ...
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1answer
943 views

How to reset netstat -e counters

I would like to reset netstat -e counters. How can I do it? Renewing the network interface may reset these counters, but it is NOT an option - the networking must not be interrupted. My OS is ...
4
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7answers
22k views

Port 80 is being used by SYSTEM (PID 4), what is that?

I am trying to use port 80 for my application server, but when I perform "netstat -aon" I get TCP 0.0.0.0:80 0.0.0.0:0 LISTENING 4 When I look up the process in ...
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2answers
101 views

How to find the count of Apache workers' at a given point for shared IPs?

One can find the number of Apache workers an IP address is consuming at an instantaneous point in time by executing: netstat -pantu | grep :80 |sort | uniq -c |grep <IP_HERE, eg: 192.168> | wc ...
3
votes
2answers
222 views

After kill -9 process won't disappear and port is still bound

We have a Java server application running on Mac OS X. Occasionally this application has become unresponsive, and we have resorted to killing it with kill -9. However, the process doesn't disappear; ...
5
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4answers
13k views

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 ...
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2answers
303 views

What are records in 'netstat' command are when using logstash?

I use logstash with embedded elasticsearch. My logstash config looks like the following: output { tdout { debug => true debug_format => "json"} elasticsearch { embedded => true ...
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2answers
194 views

Can I find the list of ports being listened by a process ordered by the time of opening?

I know I can see the list of open ports using the lsof command. I am trying to view the results ordered by timestamp of listening. The process opens multiple (~6) ports and I suspect the order of ...
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2answers
57 views

How to get the number of current connections to an external web service [closed]

My application makes many requests in a day to a webservice (say 172.20.20.20:11111) on a different server. I would like to know how I can count the number of connections that are established (the ...
0
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2answers
145 views

netstat brought up strange ip

I just ran netstat -vatn and found there was a connection ESTABLISHED on :22 from my ip and another unknown ip. Moments later I ran it again and found the connection was gone. I have a default ...
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0answers
445 views

What does “connections reset due to unexpected data” in netstat -s mean

I'm running a memcached server under heavy load from multiple web servers. While investigating some odd app level behaviour, we spotted that netstat -s on the memcached box was showing a lot of ...
5
votes
1answer
590 views

Why is rpc.lockd obscured from netstat/lsof output?

Prologue: On a number of machines, which happen to act as NFS clients, netstat reports two ports that are open with no PID listed for an associated daemon. Ordinarily this might be a bit concerning. ...