netstat, ss

둘이 상당히 비슷하지만 netstat보다 ss가 훨씬 빠르고 정확하다.

 

Common

-i - packet info

-a - all(숨겨진, 사용하지 않는 부분까지 다 보여줌)

-l - listening

-t - only TCP

-n - network info

-c - continuous(keep show)

-r - routing info

 

 

 

netstat

> network status

$ netstat -i
Kernel Interface table
Iface             MTU    RX-OK RX-ERR RX-DRP RX-OVR    TX-OK TX-ERR TX-DRP TX-OVR Flg
eth0             8888  1977363      0      0 0        722396      0      0      0 BMRU
lo              66666     1316      0      0 0          1316      0      0      0 LRU

$ netstat -n
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp        0      0 111.11.1.111:11         222.222.22.222:55555    ESTABLISHED
tcp        0     48 111.11.1.111:11         222.222.22.222:55555    ESTABLISHED
Active UNIX domain sockets (w/o servers)
Proto RefCnt Flags       Type       State         I-Node   Path
unix  2      [ ]         DGRAM                    11111    /var/run/chrony/chronyd.sock
unix  2      [ ]         DGRAM                    22222    /run/systemd/shutdownd
unix  3      [ ]         DGRAM                    3333     /run/systemd/notify
unix  2      [ ]         DGRAM                    4444     /run/systemd/cgroups-agent
unix  5      [ ]         DGRAM                    5555     /run/systemd/journal/socket
unix  13     [ ]         DGRAM                    6666     /dev/log
unix  3      [ ]         STREAM     CONNECTED     77777
unix  3      [ ]         STREAM     CONNECTED     88888    /run/dbus/system_bus_socket
unix  2      [ ]         DGRAM                    99999

iface - interface

eth0, lo - interface name

MTU - maximum transmission unit

TX, RX - transfered, received packet

Flg - flag

BMRU - BROADCAST/MODE/RUN/UP

LRU - LOOP/RUN/UP

 

proto - protocol

refCnt - reference count(해당 소켓에 붙은 프로세스 수)

DGRAM - datagram socket

 

 

ss

> socket statistics

Netid  State      Recv-Q Send-Q Local Address:Port                 Peer Address:Port                    
u_str  ESTAB      0      0                * 22222                          * 33333
u_str  ESTAB      0      0      /run/dbus/system_bus_socket 44444                          * 56666

tcp    ESTAB      0      0      111.11.1.111:ssh                  222.222.22.222:55555                  
tcp    ESTAB      0      48     111.11.1.111:ssh                  222.111.11.111:57777

Netid - network id

u_str - stream socket

TCP/UDP

 

State - status

ESTAB - established

 

Recv-Q - received packet

Send-Q - sended packet

 

Local Address:Port - ip from

Peer Address:Port - ip to