TCP/IP Internet Control Message Protocol (ICMP), RFC 792. ICMP IP-. ICMP , . - ICMP, -. , IP- c ICMP- .
ICMP : , ; -, .. ICMP .
ICMP : , . , 64 , . - . . 6.6. .
6.6.
13-14 | / | ||
ping, . , IP-, , .. , IP- . . 6.8. .
. , , ; -. ICMP- , ( ), ICMP-.
0 , . , , - .
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, .
(=3) , . . 6.9.
, . 6.7.
6.7
- ( TOS, TOS=000 | |
- |
(=4) 3, 0. - , , . , ICMP-, , .
(=5) -, , , . (.6.10) , .
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IP- , / . (0-3) (0 , 1 , 2 IP- , 3 - IP- ).
, , . , , ICMP, .
(=11) . TTL IP- , , ICMP- = 0. , . =1 .
/ ( = 13/14, =0) Internet. . 6.11. 32- ... , (UT/GMT). (Originate timestamp) - , . (Receive timestamp) - , - . - (Transmit timestamp) - , , . , , , , .
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, . .
IP
(, ) , IP- . , IP- IP- , , . , .
, -, (ARP-), , , . , , - , , (default router, default gateway). , -.
, IP-. , , . , , , , .
:
IP- () ,
IP- , ( ),
,
.
. . , , H , - ; G , .
. , , . , , . , , . , , . , , . , , . , , , .. . , , - ICMP- . , , . 6.12.
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: 149.100.1.0/25 149.100.1.128/26, 149.100.2.0/24, 1 2. 2 . . , 6 149.100.1.159. 6 6.8.
6.8.
127.0.0.0 | 255.0.0.0 | 127.0.0.1 | lo0 | |
Default | 0.0.0.0 | 149.100.2.1 | G | Eth0 |
149.100.2.0 | 255.255.255.0 | 149.100.2.21 | Eth0 |
. G , 149.100.2.1 . , , ; G , 6, 149.100.2.21.
6 2, , 2 . , , 2 149.100.2.1 Eth0. 2 .
6.9.
127.0.0.0 | 255.0.0.0 | 127.0.0.1 | lo0 | |
default | 0.0.0.0 | 149.100.0.2 | G | Serial 01 |
149.100.2.0 | 255.255.255.0 | 149.100.2.1 | Eth0 | |
149.100.1.0 | 255.255.255.128 | 149.100.1.2 | Eth1 | |
149.100.1.128 | 255.255.255.192 | 149.100.1.1 | G | Eth1 |
2 , , 5, 1 Eth1. 1 .
8.10.
default | 0.0.0.0 | 149.100.1.2 | G | Eth1 |
149.100.2.0 | 255.255.255.0 | 149.100.1.2 | G | Eth1 |
149.100.1.0 | 255.255.255.192 | 149.100.1.1 | Eth1 | |
149.100.1.159 | 255.255.255.255 | 149.100.1.159 | Eth0 | |
149.100.1.128 | 255.255.255.192 | 149.100.1.129 | Eth0 |
. Eth0 2 IP- 149.100.1.159.
. , , ( ) .
1993 (Classless InterDomain Routing, CIDR). , , (). , CIDR - , .
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. RFC 1466 , 194.0.0.0 - 195.255.255.255. 131072 , 7 . () IP 194 254.0.0.0, . ( , 194 195), , , , . , , .
, CIDR, " - (longest match)". , , , , . , ( Z) Internet, . 16 , 194.0.16.0 - 194.0.31.255. : 194.0.16.0/20 ( 255.255.240.0). 194.0.22.1 20 Z , 7 , (194.0.0.0, 254.0.0.0), ( Z). , 255.255.240 "" 254.0.0.0, , Z.