netstat

netstat este o comandă UNIX care tipărește conexiunile de rețea, tabela de routare, și un număr de statistici. Este disponibilă de asemenea sub DOS sau Windows sub forma unui program independent.

netstat [opțiuni] 

O scurtă listă a parametrilor comenzii este după cum urmează:

• -a - tipărește toate conexiunile active (în engleză all)
• -c - tipărește în mod continuu, datele pe ecran sunt actualizate odată pe secundă
• -i - tipărește datele relevante pentru interfața specificată
• -n - tipărește date numerice cum ar fi adrese de IP în loc de hostname
• -r - tipărește tabela de routare
• -s - tipărește date statistice
• --tcp - tipărește toate datele referitoare la protocolul TCP
• --udp - tipărește toate datele referitoare la protocolul UDP

Toate de exemple de mai jos provin de pe un calculator Linux.

$ netstat -a --tcp --udp Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address               Foreign Address             State       tcp        0      0 localhost.localdomain:ipp   *:*                         LISTEN       tcp        0      0 localhost.localdomain:smtp  *:*                         LISTEN       tcp        0      0 localhost6.localdomain6:ipp *:*                         LISTEN       udp        0      0 *:ipp                       *:*                                      udp        0      0 *:bootpc                    *:*                                      udp        0      0 *:mdns                      *:*                                      udp        0      0 *:36202                     *:*                                      

$ netstat -rn Kernel IP routing table Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface 192.168.254.0   0.0.0.0         255.255.255.0   U         0 0          0 eth7 0.0.0.0         192.168.254.254 0.0.0.0         UG        0 0          0 eth7 

$ 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 eth7       1500   0    32165      0      0      0    23421      0      0      0 BMRU lo        16436   0      199      0      0      0      199      0      0      0 LRU 

$ netstat -s --tcp IcmpMsg:    InType3: 13    InType8: 2    OutType0: 2    OutType3: 21    OutType8: 20 Tcp:    546 active connections openings    5 passive connection openings    34 failed connection attempts    19 connection resets received    0 connections established    30016 segments received    20868 segments send out    280 segments retransmited    0 bad segments received.    223 resets sent UdpLite: TcpExt:    38 TCP sockets finished time wait in fast timer    608 delayed acks sent    Quick ack mode was activated 166 times    22363 packets header predicted    2392 acknowledgments not containing data received    54 predicted acknowledgments    3 times recovered from packet loss due to SACK data    3 congestion windows fully recovered    2 congestion windows partially recovered using Hoe heuristic    TCPDSACKUndo: 59    76 congestion windows recovered after partial ack    0 TCP data loss events    26 timeouts after SACK recovery    1 timeouts in loss state    5 fast retransmits    211 other TCP timeouts    163 DSACKs sent for old packets    120 DSACKs received    19 connections reset due to unexpected data    4 connections reset due to early user close    2 connections aborted due to timeout    TCPDSACKIgnoredOld: 24    TCPDSACKIgnoredNoUndo: 12    TCPSackShifted: 2    TCPSackMerged: 19    TCPSackShiftFallback: 55 IpExt:    InMcastPkts: 22    OutMcastPkts: 26    InOctets: 36104049    OutOctets: 2130532    InMcastOctets: 6184    OutMcastOctets: 6344 

• en Pagina de manual
• en Net-Tool Arhivat în 6 iunie 2011, la Wayback Machine. project page on berliOS
• en Ports & Services Database
• en Microsoft TechNet Netstat article – documentation for the netstat.exe command-line program.
• en The netstat Command (Linux) – a guide to using the netstat command in Linux.
• en Security Now #49 - The NETSTAT Command – podcast guide to netstat from Security Now!.
• en From linux-ip.net More complete description of some aspects of the output.