Display Current TCP/IP Connections and Statistics
by Using Netstat
Netstat displays protocol statistics and current TCP/IP connections. Netstat -a displays all connections, and netstat -r displays the route table plus active connections. The -n switch tells netstat not to convert addresses and port numbers to names. The following is sample output:
C:\>netstat -e
Interface Statistics
Received Sent
Bytes 3995837940 47224622
Unicast packets 120099 131015
Non-unicast packets 7579544 3823
Discards 0 0
Errors 0 0
Unknown protocols 363054211
C:\>netstat -a
Active Connections
Proto Local Address Foreign Address State
TCP davemac1:1572 172.16.48.10:nbsession ESTABLISHED
TCP davemac1:1589 172.16.48.10:nbsession ESTABLISHED
TCP davemac1:1606 172.16.105.245:nbsession ESTABLISHED
TCP davemac1:1632 172.16.48.213:nbsession ESTABLISHED
TCP davemac1:1659 172.16.48.169:nbsession ESTABLISHED
TCP davemac1:1714 172.16.48.203:nbsession ESTABLISHED
TCP davemac1:1719 172.16.48.36:nbsession ESTABLISHED
TCP davemac1:1241 172.16.48.101:nbsession ESTABLISHED
UDP davemac1:1025 *:*
UDP davemac1:snmp *:*
UDP davemac1:nbname *:*
UDP davemac1:nbdatagram *:*
UDP davemac1:nbname *:*
UDP davemac1:nbdatagram *:*
C:\>netstat -s
IP Statistics
Packets Received = 5378528
Received Header Errors = 738854
Received Address Errors = 23150
Datagrams Forwarded = 0
Unknown Protocols Received = 0
Received Packets Discarded = 0
Received Packets Delivered = 4616524
Output Requests = 132702
Routing Discards = 157
Discarded Output Packets = 0
Output Packet No Route = 0
Reassembly Required = 0
Reassembly Successful = 0
Reassembly Failures = 0
Datagrams Successfully Fragmented = 0
Datagrams Failing Fragmentation = 0
Fragments Created = 0
ICMP Statistics
Received Sent
Messages 693 4
Errors 0 0
Destination Unreachable 685 0
Time Exceeded 0 0
Parameter Problems 0 0
Source Quenchs 0 0
Redirects 0 0
Echos 4 0
Echo Replies 0 4
Timestamps 0 0
Timestamp Replies 0 0
Address Masks 0 0
Address Mask Replies 0 0
TCP Statistics
Active Opens = 597
Passive Opens = 135
Failed Connection Attempts = 107
Reset Connections = 91
Current Connections = 8
Segments Received = 106770
Segments Sent = 118431
Segments Retransmitted = 461
UDP Statistics
Datagrams Received = 4157136
No Ports = 351928
Receive Errors = 2
Datagrams Sent = 13809