netstat (network statistics) is a command-line tool for monitoring network connections both incoming and outgoing as well as viewing routing tables, interface statistics, etc.
[ You might also like: 22 Linux Networking Commands for Sysadmin ]
netstat is available on all Unix-like Operating Systems and also available on Windows OS as well. It is very useful in terms of network troubleshooting and performance measurement.
netstat is one of the most basic network service debugging tools, telling you what ports are open and whether any programs are listening on ports.
Update: The Linux netstat command is replaced by new ss command, which is capable of displaying more information about network connections and it is much faster than the older netstat command.
The netstat tool is very important and much useful for Linux network administrators as well as system administrators to monitor and troubleshoot their network-related problems and determine network traffic performance.
This article shows usages of netstat command with their examples which may be useful in daily operation.
[ You might also like: 35 Practical Examples of Linux Find Command ]
1. Listing all the LISTENING Ports of TCP and UDP Connections
Listing all ports (both TCP and UDP) using netstat -a option.
<strong># netstat -a | more</strong> Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 *:sunrpc *:* LISTEN tcp 0 52 192.168.0.2:ssh 192.168.0.1:egs ESTABLISHED tcp 1 0 192.168.0.2:59292 www.gov.com:http CLOSE_WAIT tcp 0 0 localhost:smtp *:* LISTEN tcp 0 0 *:59482 *:* LISTEN udp 0 0 *:35036 *:* udp 0 0 *:npmp-local *:* Active UNIX domain sockets (servers and established) Proto RefCnt Flags Type State I-Node Path unix 2 [ ACC ] STREAM LISTENING 16972 /tmp/orbit-root/linc-76b-0-6fa08790553d6 unix 2 [ ACC ] STREAM LISTENING 17149 /tmp/orbit-root/linc-794-0-7058d584166d2 unix 2 [ ACC ] STREAM LISTENING 17161 /tmp/orbit-root/linc-792-0-546fe905321cc unix 2 [ ACC ] STREAM LISTENING 15938 /tmp/orbit-root/linc-74b-0-415135cb6aeab
2. Listing TCP Ports connections
Listing only TCP (Transmission Control Protocol) port connections using netstat -at.
<strong># netstat -at</strong> Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 *:ssh *:* LISTEN tcp 0 0 localhost:ipp *:* LISTEN tcp 0 0 localhost:smtp *:* LISTEN tcp 0 52 192.168.0.2:ssh 192.168.0.1:egs ESTABLISHED tcp 1 0 192.168.0.2:59292 www.gov.com:http CLOSE_WAIT
3. Listing UDP Ports connections
Listing only UDP (User Datagram Protocol ) port connections using netstat -au.
<strong># netstat -au</strong> Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State udp 0 0 *:35036 *:* udp 0 0 *:npmp-local *:* udp 0 0 *:mdns *:*
4. Listing all LISTENING Connections
Listing all active listening ports connections with netstat -l.
<strong># netstat -l</strong> Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 *:sunrpc *:* LISTEN tcp 0 0 *:58642 *:* LISTEN tcp 0 0 *:ssh *:* LISTEN udp 0 0 *:35036 *:* udp 0 0 *:npmp-local *:* Active UNIX domain sockets (only servers) Proto RefCnt Flags Type State I-Node Path unix 2 [ ACC ] STREAM LISTENING 16972 /tmp/orbit-root/linc-76b-0-6fa08790553d6 unix 2 [ ACC ] STREAM LISTENING 17149 /tmp/orbit-root/linc-794-0-7058d584166d2 unix 2 [ ACC ] STREAM LISTENING 17161 /tmp/orbit-root/linc-792-0-546fe905321cc unix 2 [ ACC ] STREAM LISTENING 15938 /tmp/orbit-root/linc-74b-0-415135cb6aeab
5. Listing all TCP Listening Ports
Listing all active listening TCP ports by using option netstat -lt.
<strong># netstat -lt</strong> Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 *:dctp *:* LISTEN tcp 0 0 *:mysql *:* LISTEN tcp 0 0 *:sunrpc *:* LISTEN tcp 0 0 *:munin *:* LISTEN tcp 0 0 *:ftp *:* LISTEN tcp 0 0 localhost.localdomain:ipp *:* LISTEN tcp 0 0 localhost.localdomain:smtp *:* LISTEN tcp 0 0 *:http *:* LISTEN tcp 0 0 *:ssh *:* LISTEN tcp 0 0 *:https *:* LISTEN
6. Listing all UDP Listening Ports
Listing all active listening UDP ports by using option netstat -lu.
<strong># netstat -lu</strong> Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State udp 0 0 *:39578 *:* udp 0 0 *:meregister *:* udp 0 0 *:vpps-qua *:* udp 0 0 *:openvpn *:* udp 0 0 *:mdns *:* udp 0 0 *:sunrpc *:* udp 0 0 *:ipp *:* udp 0 0 *:60222 *:* udp 0 0 *:mdns *:*
7. Listing all UNIX Listening Ports
Listing all active UNIX listening ports using netstat -lx.
<strong># netstat -lx</strong> Active UNIX domain sockets (only servers) Proto RefCnt Flags Type State I-Node Path unix 2 [ ACC ] STREAM LISTENING 4171 @ISCSIADM_ABSTRACT_NAMESPACE unix 2 [ ACC ] STREAM LISTENING 5767 /var/run/cups/cups.sock unix 2 [ ACC ] STREAM LISTENING 7082 @/tmp/fam-root- unix 2 [ ACC ] STREAM LISTENING 6157 /dev/gpmctl unix 2 [ ACC ] STREAM LISTENING 6215 @/var/run/hald/dbus-IcefTIUkHm unix 2 [ ACC ] STREAM LISTENING 6038 /tmp/.font-unix/fs7100 unix 2 [ ACC ] STREAM LISTENING 6175 /var/run/avahi-daemon/socket unix 2 [ ACC ] STREAM LISTENING 4157 @ISCSID_UIP_ABSTRACT_NAMESPACE unix 2 [ ACC ] STREAM LISTENING 60835836 /var/lib/mysql/mysql.sock unix 2 [ ACC ] STREAM LISTENING 4645 /var/run/audispd_events unix 2 [ ACC ] STREAM LISTENING 5136 /var/run/dbus/system_bus_socket unix 2 [ ACC ] STREAM LISTENING 6216 @/var/run/hald/dbus-wsUBI30V2I unix 2 [ ACC ] STREAM LISTENING 5517 /var/run/acpid.socket unix 2 [ ACC ] STREAM LISTENING 5531 /var/run/pcscd.comm
8. Showing Statistics by Protocol
Displays statistics by protocol. By default, statistics are shown for the TCP, UDP, ICMP, and IP protocols. The -s parameter can be used to specify a set of protocols.
<strong># netstat -s</strong>
Ip:
2461 total packets received
0 forwarded
0 incoming packets discarded
2431 incoming packets delivered
2049 requests sent out
Icmp:
0 ICMP messages received
0 input ICMP message failed.
ICMP input histogram:
1 ICMP messages sent
0 ICMP messages failed
ICMP output histogram:
destination unreachable: 1
Tcp:
159 active connections openings
1 passive connection openings
4 failed connection attempts
0 connection resets received
1 connections established
2191 segments received
1745 segments send out
24 segments retransmited
0 bad segments received.
4 resets sent
Udp:
243 packets received
1 packets to unknown port received.
0 packet receive errors
281 packets sent
9. Showing Statistics by TCP Protocol
Showing statistics of only TCP protocol by using option netstat -st.
<strong># netstat -st</strong>
Tcp:
2805201 active connections openings
1597466 passive connection openings
1522484 failed connection attempts
37806 connection resets received
1 connections established
57718706 segments received
64280042 segments send out
3135688 segments retransmited
74 bad segments received.
17580 resets sent
10. Showing Statistics by UDP Protocol
<strong># netstat -su</strong>
Udp:
1774823 packets received
901848 packets to unknown port received.
0 packet receive errors
2968722 packets sent
11. Displaying Service name with PID
Displaying service name with their PID number, using option netstat -tp will display “PID/Program Name“.
<strong># netstat -tp</strong> Active Internet connections (w/o servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 192.168.0.2:ssh 192.168.0.1:egs ESTABLISHED 2179/sshd tcp 1 0 192.168.0.2:59292 www.gov.com:http CLOSE_WAIT 1939/clock-applet
12. Displaying Promiscuous Mode
Displaying Promiscuous mode with -ac switch, netstat print the selected information or refresh screen every five seconds. The default screen refreshes every second.
<strong># netstat -ac 5 | grep tcp</strong> tcp 0 0 *:sunrpc *:* LISTEN tcp 0 0 *:58642 *:* LISTEN tcp 0 0 *:ssh *:* LISTEN tcp 0 0 localhost:ipp *:* LISTEN tcp 0 0 localhost:smtp *:* LISTEN tcp 1 0 192.168.0.2:59447 www.gov.com:http CLOSE_WAIT tcp 0 52 192.168.0.2:ssh 192.168.0.1:egs ESTABLISHED tcp 0 0 *:sunrpc *:* LISTEN tcp 0 0 *:ssh *:* LISTEN tcp 0 0 localhost:ipp *:* LISTEN tcp 0 0 localhost:smtp *:* LISTEN tcp 0 0 *:59482 *:* LISTEN
13. Displaying Kernel IP routing
Display Kernel IP routing table with netstat and route command.
<strong># netstat -r</strong> Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 192.168.0.0 * 255.255.255.0 U 0 0 0 eth0 link-local * 255.255.0.0 U 0 0 0 eth0 default 192.168.0.1 0.0.0.0 UG 0 0 0 eth0
14. Showing Network Interface Transactions
Showing network interface packet transactions including both transferring and receiving packets with MTU size.
<strong># netstat -i</strong> Kernel Interface table Iface MTU Met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg eth0 1500 0 4459 0 0 0 4057 0 0 0 BMRU lo 16436 0 8 0 0 0 8 0 0 0 LRU
15. Showing Kernel Interface Table
Showing Kernel interface table, similar to ifconfig command.
<strong># netstat -ie</strong>
Kernel Interface table
eth0 Link encap:Ethernet HWaddr 00:0C:29:B4:DA:21
inet addr:192.168.0.2 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::20c:29ff:feb4:da21/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:4486 errors:0 dropped:0 overruns:0 frame:0
TX packets:4077 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:2720253 (2.5 MiB) TX bytes:1161745 (1.1 MiB)
Interrupt:18 Base address:0x2000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:8 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:480 (480.0 b) TX bytes:480 (480.0 b)
16. Displaying IPv4 and IPv6 Information
Displays multicast group membership information for both IPv4 and IPv6.
<strong># netstat -g</strong> IPv6/IPv4 Group Memberships Interface RefCnt Group --------------- ------ --------------------- lo 1 all-systems.mcast.net eth0 1 224.0.0.251 eth0 1 all-systems.mcast.net lo 1 ff02::1 eth0 1 ff02::202 eth0 1 ff02::1:ffb4:da21 eth0 1 ff02::1
17. Print Netstat Information Continuously
To get netstat information every few seconds, then use the following command, it will print netstat information continuously, say every few seconds.
<strong># netstat -c</strong> Active Internet connections (w/o servers) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 tecmint.com:http sg2nlhg007.shr.prod.s:36944 TIME_WAIT tcp 0 0 tecmint.com:http sg2nlhg010.shr.prod.s:42110 TIME_WAIT tcp 0 132 tecmint.com:ssh 115.113.134.3.static-:64662 ESTABLISHED tcp 0 0 tecmint.com:http crawl-66-249-71-240.g:41166 TIME_WAIT tcp 0 0 localhost.localdomain:54823 localhost.localdomain:smtp TIME_WAIT tcp 0 0 localhost.localdomain:54822 localhost.localdomain:smtp TIME_WAIT tcp 0 0 tecmint.com:http sg2nlhg010.shr.prod.s:42091 TIME_WAIT tcp 0 0 tecmint.com:http sg2nlhg007.shr.prod.s:36998 TIME_WAIT
18. Finding non-supportive Address
Finding un-configured address families with some useful information.
<strong># netstat --verbose</strong> netstat: no support for `AF IPX' on this system. netstat: no support for `AF AX25' on this system. netstat: no support for `AF X25' on this system. netstat: no support for `AF NETROM' on this system.
19. Finding Listening Programs
Find out how many listening programs running on a port.
<strong># netstat -ap | grep http</strong> tcp 0 0 *:http *:* LISTEN 9056/httpd tcp 0 0 *:https *:* LISTEN 9056/httpd tcp 0 0 tecmint.com:http sg2nlhg008.shr.prod.s:35248 TIME_WAIT - tcp 0 0 tecmint.com:http sg2nlhg007.shr.prod.s:57783 TIME_WAIT - tcp 0 0 tecmint.com:http sg2nlhg007.shr.prod.s:57769 TIME_WAIT - tcp 0 0 tecmint.com:http sg2nlhg008.shr.prod.s:35270 TIME_WAIT - tcp 0 0 tecmint.com:http sg2nlhg009.shr.prod.s:41637 TIME_WAIT - tcp 0 0 tecmint.com:http sg2nlhg009.shr.prod.s:41614 TIME_WAIT - unix 2 [ ] STREAM CONNECTED 88586726 10394/httpd
20. Displaying RAW Network Statistics
<strong># netstat --statistics --raw</strong>
Ip:
62175683 total packets received
52970 with invalid addresses
0 forwarded
Icmp:
875519 ICMP messages received
destination unreachable: 901671
echo request: 8
echo replies: 16253
IcmpMsg:
InType0: 83
IpExt:
InMcastPkts: 117
That’s it, If you are looking for more information and options about the netstat command, refer to netstat manual docs or use the man netstat command to know all the information.
If we’ve missed anything in the list, please inform us using our comment section below. So, we could keep updating this list based on your comments.
The above is the detailed content of 20 Netstat Commands for Linux Network Management. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Install LXC (Linux Containers) in RHEL, Rocky & AlmaLinux
Jul 05, 2025 am 09:25 AM
LXD is described as the next-generation container and virtual machine manager that offers an immersive for Linux systems running inside containers or as virtual machines. It provides images for an inordinate number of Linux distributions with support
How to troubleshoot DNS issues on a Linux machine?
Jul 07, 2025 am 12:35 AM
When encountering DNS problems, first check the /etc/resolv.conf file to see if the correct nameserver is configured; secondly, you can manually add public DNS such as 8.8.8.8 for testing; then use nslookup and dig commands to verify whether DNS resolution is normal. If these tools are not installed, you can first install the dnsutils or bind-utils package; then check the systemd-resolved service status and configuration file /etc/systemd/resolved.conf, and set DNS and FallbackDNS as needed and restart the service; finally check the network interface status and firewall rules, confirm that port 53 is not
How would you debug a server that is slow or has high memory usage?
Jul 06, 2025 am 12:02 AM
If you find that the server is running slowly or the memory usage is too high, you should check the cause before operating. First, you need to check the system resource usage, use top, htop, free-h, iostat, ss-antp and other commands to check CPU, memory, disk I/O and network connections; secondly, analyze specific process problems, and track the behavior of high-occupancy processes through tools such as ps, jstack, strace; then check logs and monitoring data, view OOM records, exception requests, slow queries and other clues; finally, targeted processing is carried out based on common reasons such as memory leaks, connection pool exhaustion, cache failure storms, and timing task conflicts, optimize code logic, set up a timeout retry mechanism, add current limit fuses, and regularly pressure measurement and evaluation resources.
Install Guacamole for Remote Linux/Windows Access in Ubuntu
Jul 08, 2025 am 09:58 AM
As a system administrator, you may find yourself (today or in the future) working in an environment where Windows and Linux coexist. It is no secret that some big companies prefer (or have to) run some of their production services in Windows boxes an
How to Burn CD/DVD in Linux Using Brasero
Jul 05, 2025 am 09:26 AM
Frankly speaking, I cannot recall the last time I used a PC with a CD/DVD drive. This is thanks to the ever-evolving tech industry which has seen optical disks replaced by USB drives and other smaller and compact storage media that offer more storage
How to find my private and public IP address in Linux?
Jul 09, 2025 am 12:37 AM
In Linux systems, 1. Use ipa or hostname-I command to view private IP; 2. Use curlifconfig.me or curlipinfo.io/ip to obtain public IP; 3. The desktop version can view private IP through system settings, and the browser can access specific websites to view public IP; 4. Common commands can be set as aliases for quick call. These methods are simple and practical, suitable for IP viewing needs in different scenarios.
How to Install NodeJS 14 / 16 & NPM on Rocky Linux 8
Jul 13, 2025 am 09:09 AM
Built on Chrome’s V8 engine, Node.JS is an open-source, event-driven JavaScript runtime environment crafted for building scalable applications and backend APIs. NodeJS is known for being lightweight and efficient due to its non-blocking I/O model and
How to Setup MySQL Replication in RHEL, Rocky and AlmaLinux
Jul 05, 2025 am 09:27 AM
Data replication is the process of copying your data across multiple servers to improve data availability and enhance the reliability and performance of an application. In MySQL replication, data is copied from a database from the master server to ot
