20 Perintah Netstat untuk Manajemen Jaringan Linux
Netstat (statistik jaringan) adalah Command Line untuk koneksi jaringan monitoring baik masuk maupun keluar serta melihat tabel routing, statistik antarmuka dll. Netstat tersedia pada semua Sistem Operasi Unix-like dan juga tersedia pada Windows OS. Hal ini sangat berguna dalam hal pemecahan masalah jaringan dan pengukuran kinerja. Netstat adalah salah satu layanan jaringan alat debugging yang paling dasar, memberitahu kepada anda port apa saja yang terbuka dan apakah ada program yang terhubung dengan port.
Alat ini sangat penting dan banyak berguna bagi administrator jaringan Linux serta sistem administrator untuk memonitor dan memecahkan masalah jaringan yang terkait dan menentukan kinerja lalu lintas jaringan. Artikel ini menunjukkan penggunaan perintah netstat dengan contoh-contoh mereka yang mungkin berguna dalam operasi sehari-hari
Alat ini sangat penting dan banyak berguna bagi administrator jaringan Linux serta sistem administrator untuk memonitor dan memecahkan masalah jaringan yang terkait dan menentukan kinerja lalu lintas jaringan. Artikel ini menunjukkan penggunaan perintah netstat dengan contoh-contoh mereka yang mungkin berguna dalam operasi sehari-hari
1. Listing all the LISTENING Ports of TCP and UDP connections
Daftar semua port (TCP dan UDP) menggunakan "netstat -a | option"
# netstat -a | more
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
Daftar hanya TCP (Transmission Control Protocol) koneksi port menggunakan netstat-at.
# netstat -at
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
Daftar hanya UDP (User Datagram Protocol) koneksi port menggunakan netstat-au.
# netstat -au
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
Daftar semua port aktif yang terhubung menggunakan netstat -l.
# netstat -l
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
Daftar semua port TCP aktif dengan menggunakan opsi netstat -lt.
# netstat -lt
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
Daftar semua port UDP aktif dengan menggunakan opsi netstat -lu.
# netstat -lu
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
Daftar semua port UNIX yang aktif menggunakan netstat -lx.
# netstat -lx
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
Menampilkan statistik protocol. Secara default, statistik ditampilkan untuk TCP, UDP, ICMP, dan protokol IP. Parameter -s dapat digunakan untuk menentukan satu set protokol.
# netstat -s
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
Menampilkan statistik hanya protokol TCP dengan menggunakan opsi netstat -st.
# netstat -st
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
Menampilkan statistik hanya protokol UDP dengan menggunakan opsi netstat -su.
# netstat -su
Udp:
1774823 packets received
901848 packets to unknown port received.
0 packet receive errors
2968722 packets sent
11. Displaying Service name with PID
Menampilkan nama layanan dengan nomor PID mereka, menggunakan opsi netstat-tp akan menampilkan “PID/Program Name”.
# netstat -tp
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
Menampilkan modus Promiscuous dengan -ac switch, netstat mencetak informasi yang dipilih atau menyegarkan layar setiap lima detik. Standar refresh layar dalam setiap detik.
# netstat -ac 5 | grep tcp
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
Tampilan Kernel IP routing table dengan netstat dan perintah route.
# netstat -r
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
Menampilkan antarmuka jaringan paket transaksi termasuk mentransfer dan menerima paket dengan ukuran MTU.
# 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 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
Menampilkan tabel antarmuka Kernel, mirip dengan perintah ifconfig.
# netstat -ie
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
Informasi keanggotaan grup multicast untuk menampilkan IPv4 dan IPv6.
# netstat -g
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
Untuk mendapatkan informasi netstat setiap beberapa detik, kemudian gunakan perintah berikut, itu akan mencetak informasi netstat terus menerus, langsung setiap beberapa detik.
# netstat -c
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
Mencari kelompok alamat un-dikonfigurasi dengan beberapa informasi yang berguna.
# netstat --verbose
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
Cari tahu berapa banyak program yang berjalan pada koneksi port.
# netstat -ap | grep http
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
# netstat --statistics --raw
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
Itu saja, Jika Anda mencari informasi lebih lanjut dan pilihan tentang perintah netstat, lihat netstat docs manual atau menggunakan perintah man netstat untuk mengetahui semua informasi.