1 cs4550 computer networks ii topics in applications ref: feit chap 13-20 tanenbaum chap 7
TRANSCRIPT
1
CS4550 Computer Networks II
Topics In Applications
Ref: Feit Chap 13-20Tanenbaum Chap 7
Clients, requestor programs Servers, demon, reply peerT
elne
t
FT
P
SN
MP
E-m
ail
WW
W
Tel
net
FT
P
SN
MP
E-m
ail
WW
W
TCP UDP
IP
DL and physical
TCP UDP
IP
DL and physical
From Port 23
From Protocol 6
To port 23
To protocol 6
General Architecture
Common Tools
Ping Echo 7/udp
netstat time 13/udp
traceroute tracert quote 17/udp
TELNET
First Application
Connect as a terminal to a networked host
Terminal emulation
Telnet to selected port
Commands
Connect as a terminal to a networked host
NVT - Network Virtual Terminal Solves Multi vendor problem
NVT code - 7 bit USASCII 128 characters
Line Format- half duplex, stop and wait, <CR><LF>
Command Format - Interpret As Command (IAC)
Escape character IAC = 255 note 8’th bit set
IAC Command option
255 251 24
will terminal type
Terminal emulation
Telnet cs.nps.navy.mil 7 echo service
telnet cs.nps.navy.mil 13 time of day service
telnet cs.nps.navy.mil 80 www service
telnet cs.nps.navy.mil 25 mail service
type help
Connect to a selected port
Telnet Commandsget a list of commands
Wolf> telnet
telnet > ?