Visualizzazione delle statistiche per quanto riguarda la network.
Utili per capire se il vostro server ha problemi, anomalie in ambito network o semplicemente per dedurre quanto traffico ha prodotto la vostra macchina.
[neo@dido neo]$ netstat -s
Statistiche relative ai pacchetti IP
Ip:
14743 total packets received
0 forwarded
0 incoming packets discarded
14385 incoming packets delivered
15907 requests sent out
Statistiche relative ai pacchetti ICMP
Icmp:
6 ICMP messages received
0 input ICMP message failed.
ICMP input histogram:
destination unreachable: 6
6 ICMP messages sent
0 ICMP messages failed
ICMP output histogram:
destination unreachable: 6
Statistiche relative ai pacchetti TCP
Tcp:
1039 active connections openings
0 passive connection openings
0 failed connection attempts
0 connection resets received
2 connections established
14419 segments received
15721 segments send out
145 segments retransmited
0 bad segments received.
25 resets sent
Statistiche relative ai pacchetti UDP
Udp:
169 packets received
2 packets to unknown port received.
0 packet receive errors
180 packets sent
TcpExt:
ArpFilter: 0
567 TCP sockets finished time wait in fast timer
7 packets rejects in established connections because of timestamp
269 delayed acks sent
Quick ack mode was activated 134 times
16 packets directly queued to recvmsg prequeue.
400 packets directly received from prequeue
6182 packets header predicted
16 packets header predicted and directly queued to user
TCPPureAcks: 1336
TCPHPAcks: 1195
TCPRenoRecovery: 0
TCPSackRecovery: 0
TCPSACKReneging: 0
TCPFACKReorder: 0
TCPSACKReorder: 0
TCPRenoReorder: 0
TCPTSReorder: 0
TCPFullUndo: 0
TCPPartialUndo: 0
TCPDSACKUndo: 0
TCPLossUndo: 0
TCPLoss: 0
TCPLostRetransmit: 0
TCPRenoFailures: 0
TCPSackFailures: 1
TCPLossFailures: 0
TCPFastRetrans: 0
TCPForwardRetrans: 0
TCPSlowStartRetrans: 0
TCPTimeouts: 69
TCPRenoRecoveryFail: 0
TCPSackRecoveryFail: 0
TCPSchedulerFailed: 0
TCPRcvCollapsed: 0
TCPDSACKOldSent: 158
TCPDSACKOfoSent: 29
TCPDSACKRecv: 0
TCPDSACKOfoRecv: 0
TCPAbortOnSyn: 0
TCPAbortOnData: 4
TCPAbortOnClose: 34
TCPAbortOnMemory: 0
TCPAbortOnTimeout: 8
TCPAbortOnLinger: 0
TCPAbortFailed: 0
TCPMemoryPressures: 0
I comandi e le tecniche per diagnosticare la rete: netstat, arp, tcpdump.