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The TCP/IP Guide

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Table Of Contents  The TCP/IP Guide
 9  TCP/IP Application Layer Protocols, Services and Applications (OSI Layers 5, 6 and 7)
      9  TCP/IP Key Applications and Application Protocols
           9  TCP/IP Administration and Troubleshooting Utilities and Protocols

Previous Topic/Section
TCP/IP DNS Registry Database Lookup Utility (whois/nicname)
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Pages in Current Topic/Section
123
4
56
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TCP/IP Configuration Utilities (ipconfig, winipcfg and ifconfig)
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TCP/IP Network Status Utility (netstat)
(Page 4 of 6)

Sample UNIX netstat Output

The netstat command can produce a startling amount of output, especially if you do not restrict it with some of the options in Table 297. This is particularly true for netstat by itself and with the “-s” option. In Table 298 I have shown sample output from running “plain” netstat, but I have truncated the list of connections so it would not be too long (I also reformatted the table so it would display better). Notice the last column, which shows the current state of the TCP connection (see, that TCP finite state machine stuff was useful after all! J) Table 299 shows an example of the output of “netstat -s”; here I have shortened the size of the output by using “-p ip” to tell the program to only show me the statistics for the Internet Protocol.


Table 298: Sample Connections List From UNIX netstat Utility

%netstat
Active Internet connections
Prot Rcv Snd Local Address Foreign Address (state)
tcp4 0 0 pcguide.com.http c-24-118-141-124.3384 ESTABLISHED
tcp4 0 827 pcguide.com.http webcacheB03a.cac.46075 ESTABLISHED
tcp4 0 0 qs36.smtp MV1-24.171.17.64.1339 ESTABLISHED
tcp4 0 0 pcguide.com.http 1Cust234.tnt1.le.1338 ESTABLISHED
tcp4 0 0 pcguide.com.http 1Cust234.tnt1.le.1337 FIN_WAIT_1
tcp4 0 84 pcguide.com.http dial81-131-97-70.2902 FIN_WAIT_1
tcp4 0 0 pcguide.com.http 216.76.14.221.9954 FIN_WAIT_2
tcp4 0 0 pcguide.com.http 216.76.14.221.9945 FIN_WAIT_2
tcp4 0 0 pcguide.com.http 1Cust234.tnt1.le.1326 TIME_WAIT



Table 299: Sample IP Statistics From UNIX netstat Utility

%netstat -s -p ip
ip:
57156204 total packets received
0 bad header checksums
4 with size smaller than minimum
0 with data size < data length
0 with ip length > max ip packet size
0 with header length < data size
0 with data length < header length
0 with bad options
0 with incorrect version number
138 fragments received
6 fragments dropped (dup or out of space)
128 fragments dropped after timeout
2 packets reassembled ok
57085912 packets for this host
24736 packets for unknown/unsupported protocol
0 packets forwarded (0 packets fast forwarded)
44957 packets not forwardable
4 packets received for unknown multicast group
0 redirects sent
66183465 packets sent from this host
177 packets sent with fabricated ip header
0 output packets dropped due to no bufs, etc.
0 output packets discarded due to no route
0 output datagrams fragmented
0 fragments created
0 datagrams that can't be fragmented
0 tunneling packets that can't find gif
22 datagrams with bad address in header


Previous Topic/Section
TCP/IP DNS Registry Database Lookup Utility (whois/nicname)
Previous Page
Pages in Current Topic/Section
123
4
56
Next Page
TCP/IP Configuration Utilities (ipconfig, winipcfg and ifconfig)
Next Topic/Section

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Version 3.0 - Version Date: September 20, 2005

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