, , . . . ifconfig.
:
root# ifconfig eth0 192.168.0.1 netmask 255.255.255.0 upeth0 IP- 192.168.0.1 255.255.255.0. up . , . ifconfig eth0 down.
. , , , , . , , . , , 192.168.0.0 192.168.0.255.
ifconfig , :
Up
( ).
Down
Arp
(arp) .
Allmulti
(multicast-). , . ',
Mtu N
MTU
netmask <addr>
,
irq <addr>
IRQ
[-]broadcast [addr]
.
[-]pointopoint [addr]
' - ( slip ppp)
hw <type> <addr>
. ethernet, , X.25
ifconfig - . , pppd dip .
.
ʳ , ' . . , - , . `127.0.0.1'. , telnet 127.0.0.1 - , ' . ( 䳿 ).
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.
, . , , , , ' .
. , IP-?
IP- , , IP-.
. , PPP-' , ethernet- PPP-' . IP-, , . , , , , , ethernet-, PPP SLIP.
? , . - . , ' , , IP- , . Linux, :
user% cat /proc/net/route:
user% /sbin/route -n user% netstat -r: IP-, ( , ) . . - , , , , .
route. , , .
. , ethernet-. 192.168.1.0. 192.168.1.10 , , 192.168.1.1.
. :
root# ifconfig eth0 192.168.1.10 netmask 255.255.255.0 upϳ , 192.168.1.* eth0. :
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-net. , . -host IP-.
IP-' ethernet-. ?
IP- , . , . . :
root# route add default gw 192.168.1.1 eth0gw route IP- ' , , .
:
root# ifconfig eth0 192.168.1.10 netmask 255.255.255.0 up root# route add -net 192.168.1.0 netmask 255.255.255.0 eth0 root# route add default gw 192.168.1.1 eth0rc , , , , . .
. , . PPP-' ethernet-. :
root# route add -net 192.168.1.0 netmask 255.255.255.0 eth0 root# route add -net 192.168.2.0 netmask 255.255.255.0 eth1 root# route add -net 192.168.3.0 netmask 255.255.255.0 eth2 root# route add default ppp0. ' . , . , gw. . ' , PPP SLIP (' -) ' . , ' , . , ethernet, arcnet token ring , .
ping - ICMP ECHO_REQUEST
/usr/sbin/ping [ ]
/usr/sbin/ping -s [-drvRlfnq] [-i ] [ -p ] [ _ [_] ]
ping ECHO_REQUEST ICMP, ICMP ECHO_RESPONSE . , ping , ( is alive), . , , (no answer from ). - - 20 .
-s, ping ECHO_RESPONSE. ping (round trip times) ; - . ' (_), ping . , . , , (Ctrl+C).
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64 , _. , ping 8- , , -s _, 8 , .
ping , ping , , .
ping :
-d | . SO_DEBUG. |
-f | ping. , , . ECHO_REQUEST ".", ECHO_REPLY (backspace). , . ҳ . . |
-i _ | _ . . -f. |
-l | . IP . -R. -l localhost `uname -n`. |
-n | ҳ . . |
-p | . , 16 . . , -p ff . , ' . |
-q | . , . |
-r | . , . , |
-R | . IP, IP. , -v , , -l. |
-s | ECHO_RESPONSE ( , ). |
-v | . ICMP, ECHO_RESPONSE. |
netstat -
netstat [-Aan] [-f _ ] [ -I ] [-p _] [] [core]
netstat [-n] [-s] [-i | -r ] [-f _ ] #@: #@; #@< #@=
netstat #@> #@? #@@ #@A
netstat , ' , .
(sockets) . .
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; , .
- /unix; core /dev/kmem.
netstat :
-a | ; , , . | ||||||
-A | - , ' ; . | ||||||
-i | (auto-configured) . , , , . | ||||||
-n | . netstat . - . | ||||||
-r | . -s, . | ||||||
-s | . -r, . | ||||||
-f _ | _, :
| ||||||
-I | ; ( ) ' . - , , , emd1 lo0. | ||||||
-p _ | _, tcp. |
( )
,
( ), , .
, , - :
_.
' , :
.
, . /etc/hosts /etc/networks.
' ( -n), . "" " *"..
TCP
TCP :
CLOSED | . . | |
LISTEN | '. | |
SYN_SENT | '. | |
SYN_RECEIVED | '. | |
ESTABLISHED | ' . | |
CLOSE_WAIT | ³ ; . | |
FIN_WAIT_1 | ; '. | |
CLOSING | , ; . | |
LAST_ACK | ³ , ; . | |
FIN_WAIT_2 | ; . | |
TIME_WAIT | . | |
( )
, , , -i -r. , netstat -i.
(routes) . (gateway), . flags() (U, ), (G), (D) (H) . , (loopback transport provider ), lo0, H.
, ; gateway () .
refcnt . , ', ' , ' .
use , .
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interface , .
( )
, netstat , 糿. ,
24- , , . , .
netstat, .