- IP. 4 , IP . , , , - . , , , .
4 , . Unix routed gated. (daemon) , " " . , , , . , , , .
. , , IP .
.
1. .
2. .
3. . ( .)
.
, IP , , , . , , , . IP , .
. svr 4 netstat -r, , -n, IP , . -n netstat /etc/networks, . , .
4 , IP .
Destination | Gateway | Flags | Refcnt | Use | Interface |
140.252.13.65 | 140.252.13.35 | UGH | emd0 | ||
127.0.0.1 | 127.0.0.1 | UH | lo0 | ||
default | 140.252.13.33 | UG | emd0 | ||
140.252.13.32 | 140.252.13.34 | U | emd0 |
, 140.252.13.65 ( slip) (), , 140.252.13.35 (bsdi). slip bsdi SLIP , bsdi Ethernet, .
5 .
|
|
U - .
G - (). , , .
H - , , . , , , : .
D - .
M - .
G , (indirect route) (direct route). ( G .) , , , IP ( 4). , IP , . ( G ), IP , , IP (140.252.13.65), , IP 140.252.13.35.
G , . H , ( netstat) . H , ( 0). : IP , - . netstat , , , .
(reference count) . , , TCP, , . Telnet svr 4 slip, 1. Telnet , 2, .
(use) , . ping, 5 , 5 , . (interface) .
loopback , lo0. G , . H , (127.0.0.1) , . G , , gateway IP .
. . , 140.252.13.33 (sun), . , svr 4 Internet sun ( SLIP ) . IP . (UG) , .
|
|
Ethernet. H , , (140.252.13.32) , 0. , 5 0. ( G ), gateway IP .
, , netstat. , (140.252.13.32). IP 140.252.13.33, , , . , , , .
:
1. ) , 4.2 BSD 4.3 BSD . , - 140.1. 4.2 BSD , (140.1.0.0), 4.3BSD , (140.1.255.255). , 4.2 BSD , . , , 4.2 BSD IP 140.1.255.255.
b) , - , ARP 140.1. ( arp), , IP 140.1.255.255 Ethernet ( Ethernet). , .
2. .
: 1.1, 1.2, 1.3, 2.2
8
: TCP/IP
: TCP/IP. TCP/IP. TCP/IP OSI.
: 2