ICMP
ICMP (. Internet Control Message Protocol ) , TCP/IP. ICMP , , , , , . ICMP .
ICMP RFC 792 ( RFC 950) ( STD 5 IP). ICMP IP (ICMP- IP ), IP TCP/IP. ICMP IPv4 ICMPv4. IPv6 ICMPv6.
ICMP- IP-, ICMP-. IP ICMP- IP ( ICMP- ) .
, (, ), IP-, Time to live (TTL) IP , TTL 0, ICMP- TTL .
ICMP- IP-, , , UDP, ICMP ( TCP).
ICMP IP. , TCP UDP: , , . ICMP ( Ping Traceroute).
ICMP-
ICMP- ( 12) IP- ( ICMP-, ICMP- ICMP-).
ICMP- ( 3) .
Ping, IP- ICMP- 8 (-) 0 (-).
Traceroute, IP-, ICMP- 11.
ICMP- 5 .
ICMP- 4 ( ) .
ICMP
ICMP ( )
- 0 -
- 1
- 2
- 3
0
1
2
3
4 , (DF)
5
6
7
8
9
10
11 ToS
12 ToS
13
14
15
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- 4 ( )
- 5
0
1
2 (TOS)
3
- 6
- 7
- 8 -
- 9 (RFC-1256)
0
16
- 10 (RFC-1256)
- 11 ( )
0 (TTL)
1 ( )
- 12 ( : IP- )
0
1
2
- 13
- 14
- 15
- 16
- 17 (RFC-950)
- 18 (RFC-950)
- 19 ( )
- 20-29 ( )
- 30 (RFC-1393)
- 31 (RFC-1475)
- 32
- 33 IPv6 Where-Are-You ( )
- 34 IPv6 I-Am-Here ( )
- 35
- 36
- 37 (Domain Name Request)
- 38 (Domain Name Reply)
- 39 SKIP
- 40 Photuris
0
1 (Unkown Security Parameters Index)
2 , (Valid Security Parameters, but Authentication Failed)
3 , (Valid Security Parameters, but Decryption Failed)
4 (Need Authentication)
5 (Need Authorization)
- 41-255
- ICMP- .
- ICMP- IP- , ( " ").
- IP- ICMP- , IP- .
PING
ping TCP/IP, .
ping ( ) () .
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(ICMP Echo-Request) ICMP (ICMP Echo-Reply). (RTT, . Round Trip Time) (RTT) , .
, .
ICMP- , ( - ) ICMP Echo-Reply ICMP Echo-Request.
ping TCP/IP . ping , ping SNMP RFC 2925 (Definitions of Managed Objects for Remote Ping, Traceroute, and Lookup Operations).
ICMP- raw-
, ping UNIX- . ping /bin/ping SUID-., .
:
- PING P acket I nter N et G rouper (Groper).
- Ping -. , , - .
- Pong (ICMP Echo-Reply), ping.
(. Mike Muuss), (. Ballistics Research Lab) 1983 .
- IP- .
- , . , , - .
- , . , DNS , ping , IP-.
- , , . , . , ICMP .
TRACEROUTE
Traceroute , TCP/IP. Traceroute . UDP, TCP, ICMP GRE. , Windows ICMP , Cisco - UDP.
traceroute gnome-nettool Ubuntu 6.10
Traceroute . Microsoft Windows tracert, GNU/Linux, Cisco IOS Mac OS traceroute.
Windws. tracert , , . - , . , . , , . ICMP , , . , ICMP , .
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traceroute ICMP- ( 3 ), TTL ( ) 1. , . TTL, 1, ICMP- "time exceeded in transit", . Traceroute , ( ). traceroute , TTL, 2, TTL . , TTL=1, "time exceeded in transit".
, . .
IP- TTL = 1 ICMP- , . : traceroute UDP- . 33434 + ( ) - 1. UDP-, , ICMP- . , , traceroute , ICMP- .