The most popular use of the internet. People have email addresses such
as 'akochis@austin.cc.tx.us'.
A wide variey of devices can recieve email such as phone and pagers.
$ mail president@whitehouse.gov <good.job.memo $ mail vice-president@whitehouse.gov <internet.award
venus : ftp charon Connected to charon.domain.com. 220 charon FTP server (Version 5.2 Fri Sep 7 14:09:58 CDT 1990) ready. Name (charon:kochis): kochis 331 Password required for kochis. Password: 230 User kochis logged in. ftp> cd C 250 CWD command successful. ftp> get date.c 200 PORT command successful. 150 Opening ASCII mode data connection for date.c (2536 bytes). 226 Transfer complete. local: date.c remote: date.c 2657 bytes received in 0.048 seconds (54 Kbytes/s) ftp> quit 221 Goodbye.
hermes : ls Accounting Mail Outline Tools date.c Calendar Misc Problems Tutdb jbyrd.twmrc Code NewDB Remind Xnu_tpu med hermes : rsh charon -l kochi5 ls Accounting/ Cpr/ Problems/ Tcp/ bin/ Acct-Scripts/ Mail/ Scripts/ Text/ nuTPU/
venus : telnet cochise Trying 129.116.16.14 ... Connected to cochise.domain.com. Escape character is '^]'. SunOS UNIX (cochise) login: kochis Password: Last login: Tue Nov 24 09:00:27 from venus.domain.com SunOS Release 4.1.2 (merworth) #3: Wed Mar 25 14:54:36 CST 1992 cochise : exit
venus : rlogin cochise Last login: Tue Nov 24 09:00:50 from venus.domain.com SunOS Release 4.1.2 (merworth) #3: Wed Mar 25 14:54:36 CST 1992 cochise : exit Connection closed. venus :
hermes : ls /charon/home/kochis Accounting Cpr Problems Tcp bin Acct-Scripts Mail Scripts Text nuTPU C Man Tar Zeta charon% ls /hermes/home/kochis Mail/ bin/ convex/ nu_tpu.def tpu3.0/ ask@ common/ dev/ nutpu.tar
$ finger quake@geophys.washington.edu
[geophys.washington.edu]
Login name: quake In real life: Earthquake Information
Directory: /u0/quake Shell: /u0/quake/run_quake
Last login Wed Apr 13 11:05 on ttypd from carson.u.washing
Plan:
ATTENTION: Earthquake information on world-wide earthquakes
from by the National Earthquake Information Service is no longer provided here.
One can now obtain this information directly from the NEIC with:
finger quake@gldfs.cr.usgs.gov
The following catalog is is for earthquakes (M>2) in Washington and Oregon
produced by the Washington Regional Seismograph Network, a member of the
Council of the National Seismic System. Catalogs for other regions of the
country can be obtained by using `finger quake@' the following host computers:
fm.gi.alaska.edu (Alaska), scec.gps.caltech.edu (souther California),
gldfs.cr.usgs.gov (large world-wide), slueas.slu.edu (central US),
seismo.unr.edu (Nevada), eqinfo.seis.utah.edu (Utah), andreas.wr.usgs.gov
(northern California).
Additional catalogs of the WRSN are available by anonymous ftp in:
`ftp.geophys.washington.edu:pub/seis-net'
DATE-TIME is in Universal Time (UTC) which is PST + 8 hours. Magnitudes are
reported as local magnitude (Ml). QUAL is location quality A-good, D-poor,
Z-from automatic system and may be in error.
DATE-(UTC)-TIME LAT(N) LON(W) DEP MAG QUAL COMMENTS
yy/mm/dd hh:mm:ss deg. deg. km Ml
94/03/22 21:41:28 42.28 122.01 4.9 2.6 A 21.7 km WNW of Klamath Falls,
94/03/23 09:35:29 42.28 122.01 5.5 2.0 A 21.7 km WNW of Klamath Falls,
94/03/24 09:12:35 42.31 122.05 6.7 2.0 A 25.7 km WNW of Klamath Falls,
94/03/24 18:01:01 42.31 122.03 8.2 2.0 A 24.5 km WNW of Klamath Falls,
94/03/25 17:12:35 45.05 122.61 18.5 2.0 B 20.4 km ESE of Woodburn, OR
94/03/26 11:01:09 46.16 120.68 10.3 2.1 B 48.8 km SSW of Yakima
94/03/26 23:21:58 42.26 121.96 9.4 2.1 A 16.8 km WNW of Klamath Falls,
94/03/27 23:50:06 48.53 123.45 24.9 2.0 A 15.5 km NNW of Victoria,BC
94/03/28 19:14:00 43.28 123.25 7.2 2.0 B 10.7 km NE of Roseburg, OR
94/03/28 21:46:47 44.61 122.80 8.9 2.0 C 39.3 km SSE of Salem, OR
94/03/28 23:08:15 42.26 121.90 3.0 2.7 A 12.4 km WNW of Klamath Falls,
94/03/29 06:50:19 42.25 121.96 10.1 2.4 A 15.7 km W of Klamath Falls,
94/04/01 03:38:48 47.65 120.13 7.6 2.9 B FELT 5.9 km E of Entiat
94/04/01 04:38:56 48.90 121.93 2.5 2.2 B 18.2 km NNW of Mount Baker
94/04/03 02:34:09 42.23 121.96 9.8 2.2 A 15.6 km W of Klamath Falls,
94/04/05 00:30:59 47.03 119.93 0.6 2.0 B 10.4 km NNE of Vantage
94/04/07 22:00:07 49.16 122.30 10.0 2.2 C 38.9 km N of Deming
94/04/08 08:50:57 42.30 122.05 6.5 2.0 A 25.1 km WNW of Klamath Falls,
94/04/10 16:40:04 49.23 119.56 10.0 2.5 B 29.0 km S of Penticton, BC
94/04/12 17:56:45 42.20 121.81 0.0 2.2 B 4.5 km WSW of Klamath Falls,
To see the network interfaces.
$ netstat -i
Name Mtu Network Address Ipkts Ierrs Opkts Oerrs Coll
lo0 1536 574084 0 574084 0 0
lo0 1536 127 localhost 574084 0 574084 0 0
en0 1500 2742135 0 2726850 0 0
en0 1500 198.214.96 ine.domain.com 2742135 0 2726850 0 0
tr0 1492 220899 0 103635 0 0
tr0 1492 198.214.100 ite.domain.com 220899 0 103635 0 0
$ ifconfig en0
en0: flags=4e080863<UP,BROADCAST,NOTRAILERS,RUNNING,SIMPLEX,MULTICAST,
GROUPRT,64BIT,PSEG>
inet 198.214.96.7 netmask 0xffffff00 broadcast 198.214.96.255
To see the routing tables.
$ netstat -r Routing tables Destination Gateway Flags Refcnt Use Interface default 198.214.96.3 UG 11 1876016 en0 127 localhost U 4 22636 lo0 192.168 198.214.96.5 UG 0 8625 en0 198.214.96 ine.domain.com U 1 13864 en0 198.214.97 router1.domain.com UG 5 673520 en0 198.214.100 router2.domain.com U 5 615216 tr0
To see if another host is there
$ ping mit.edu PING mit.edu (18.72.2.1): 56 data bytes 64 bytes from 18.72.2.1: icmp_seq=0 ttl=238 time=94 ms 64 bytes from 18.72.2.1: icmp_seq=1 ttl=238 time=86 ms 64 bytes from 18.72.2.1: icmp_seq=2 ttl=238 time=89 ms C64 bytes from 18.72.2.1: icmp_seq=4 ttl=238 time=89 ms 64 bytes from 18.72.2.1: icmp_seq=5 ttl=238 time=86 ms ^C --- mit.edu ping statistics --- 6 packets transmitted, 5 packets received, 16% packet loss round-trip min/avg/max = 86/88/94 ms
$ nslookup mit.edu Server: ine Address: 0.0.0.0 Non-authoritative answer: Name: mit.edu Address: 18.72.2.1 $ nslookup 18.72.2.1 Server: ine Address: 0.0.0.0 Name: MIT.MIT.EDU Address: 18.72.2.1
To see a route
$ traceroute mit.edu
traceroute to mit.edu (18.72.2.1), 30 hops max, 40 byte packets
1 129.117.19.1 (129.117.19.1) 1 ms 1 ms 1 ms
2 ut2-e3.the.net (129.117.5.17) 2 ms 2 ms 2 ms
3 ut8-f0-0.the.net (129.117.20.8) 2 ms 2 ms 2 ms
4 sprint-gw-h2-0.the.net (129.117.16.242) 5 ms 5 ms 5 ms
5 sl-fw-5-H2/0-T3.sprintlink.net (144.228.35.5) 394 ms 388 ms 19 ms
6 sl-fw-6-F0/0.sprintlink.net (144.228.30.6) 12 ms 9 ms 8 ms
7 sl-ana-1-H2/0-T3.sprintlink.net (144.228.10.30) 32 ms 32 ms 32 ms
8 sl-ana-2-F0/0.sprintlink.net (144.228.70.2) 33 ms 32 ms 33 ms
9 sl-stk-6-H2/0-T3.sprintlink.net (144.228.10.25) 156 ms 208 ms 42 ms
10 sl-stk-nap-H2/0-T3.sprintlink.net (144.228.10.50) 62 ms 47 ms 46 ms
11 pb-F1.MCI.net (198.32.128.197) 44 ms 46 ms 45 ms
12 borderx1-hssi3-0.SanFrancisco.mci.net (204.70.158.105) 47 ms 47 ms 46 ms
13 core-fddi-0.SanFrancisco.mci.net (204.70.2.161) 176 ms 138 ms 219 ms
14 core-hssi-2.Denver.mci.net (204.70.1.37) 232 ms 71 ms 70 ms
15 core2-hssi-2.WestOrange.mci.net (204.70.1.110) 83 ms 80 ms 81 ms
16 core1-aip-4.WestOrange.mci.net (204.70.1.65) 81 ms 129 ms 83 ms
17 core-hssi-4.NewYork.mci.net (204.70.1.97) 82 ms 84 ms 81 ms
18 core-hssi-3.Boston.mci.net (204.70.1.2) 86 ms 85 ms 84 ms
19 border1-fddi-0.Boston.mci.net (204.70.2.34) 86 ms 86 ms 85 ms
20 nearnet.Boston.mci.net (204.70.20.6) 169 ms 149 ms 238 ms
21 w91-rtr-external-fddi.mit.edu (192.233.33.1) 87 ms 89 ms 89 ms
22 E40-RTR-FDDI.MIT.EDU (18.168.0.2) 87 ms 86 ms 90 ms
23 MIT.MIT.EDU (18.72.2.1) 87 ms 87 ms *
to see statistics
$ netstat -s
ip:
3492986 total packets received
0 bad header checksums
0 with size smaller than minimum
0 with data size < data length
0 with header length < data size
0 with data length < header length
0 fragments received
0 fragments dropped (dup or out of space)
0 fragments dropped after timeout
230 packets forwarded
8294 packets not forwardable
24 redirects sent
icmp:
15541 calls to icmp_error
0 errors not generated 'cuz old message was icmp
Output histogram:
echo reply: 666
destination unreachable: 15408
routing redirect: 24
time exceeded: 6
572 messages with bad code fields
0 messages < minimum length
0 bad checksums
0 messages with bad length
Input histogram:
echo reply: 589
destination unreachable: 11505
source quench: 106
echo: 666
time exceeded: 2746
address mask request: 23
666 message responses generated
tcp:
2121934 packets sent
1482860 data packets (641955489 bytes)
48759 data packets (23147400 bytes) retransmitted
246444 ack-only packets (114324 delayed)
0 URG only packets
20293 window probe packets
268327 window update packets
55332 control packets
1943939 packets received
852512 acks (for 640675873 bytes)
76699 duplicate acks
0 acks for unsent data
894473 packets (329187152 bytes) received in-sequence
7847 completely duplicate packets (387394 bytes)
106 packets with some dup. data (2906 bytes duped)
47897 out-of-order packets (138730 bytes)
19 packets (0 bytes) of data after window
0 window probes
85118 window update packets
50 packets received after close
126 discarded for bad checksums
0 discarded for bad header offset fields
0 discarded because packet too short
7392 connection requests
66458 connection accepts
69329 connections established (including accepts)
76311 connections closed (including 12420 drops)
4967 embryonic connections dropped
526761 segments updated rtt (of 547856 attempts)
32339 retransmit timeouts
78 connections dropped by rexmit timeout
20742 persist timeouts
3338 keepalive timeouts
1263 keepalive probes sent
521 connections dropped by keepalive
udp:
0 incomplete headers
1 bad data length field
1 bad checksum
0 socket buffer overflows
It is possible to use the network commands in scripts such as
$ cat netpulse #!/bin/sh # # get interface names from ifconfig # tname=`/etc/ifconfig tr0 | tail -1 | tr -s ' ' ':' | cut -d: -f2` iname=`/etc/ifconfig en0 | tail -1 | tr -s ' ' ':' | cut -d: -f2` # # get statisitics from netstat # q=`netstat -i | grep '^en0' | grep '198\.214' | tr -s ' ' ':'` r=`netstat -i | grep '^tr0' | grep '198\.214' | tr -s ' ' ':'` ei1=`echo $q | cut -d: -f5` eo1=`echo $q | cut -d: -f7` ti1=`echo $r | cut -d: -f5` to1=`echo $r | cut -d: -f7` # # wait 10 sceconds # sleep 10 # # get statistics again # q=`netstat -i | grep '^en0' | grep '198\.214' | tr -s ' ' ':'` r=`netstat -i | grep '^tr0' | grep '198\.214' | tr -s ' ' ':'` ei2=`echo $q | cut -d: -f5` eo2=`echo $q | cut -d: -f7` ti2=`echo $r | cut -d: -f5` to2=`echo $r | cut -d: -f7` # # compute 10 second difference # eirpm=`expr $ei2 - $ei1` eorpm=`expr $eo2 - $eo1` tirpm=`expr $ti2 - $ti1` torpm=`expr $to2 - $to1` # # display results # echo "$iname\tI=$eirpm\tO=$eorpm" echo "$tname\tI=$tirpm\tO=$torpm" $ netpulse 198.214.96.1 I=80 O=0 198.214.100.239 I=3 O=2 $ netpulse 198.214.96.1 I=28 O=0 198.214.100.239 I=2 O=0