1. ICMP (Internet Control Message Protocol) . , ICMP , IP. ICMP [1], (. 1). , , , 404 HTTP.
, IP
, IP 64 ,
. 1 ICMP
ICMP IPv4 RFC 792, RFC 950 [2]. ICMP IPv6 RFC 4443 [3].
ping traceroute RFC 2529 [4].
2. ping (Packet Internet Groper ) , , . TCP/IP ( ) , , . ping , . , , , - , , , , . ping TCP/IP .
- ping, , IP , -. - ( - n) , (Ctrl+C Del), . - , , Windows 4. ( DDOS-) -. , ping.
, : ping _ ping IP-.
:
C:\Users\admin>ping yandex.ru
yandex.ru [77.88.21.11] 32 :
77.88.21.11: =32 =1651 TTL=57
77.88.21.11: =32 =154 TTL=57
77.88.21.11: =32 =79 TTL=57
77.88.21.11: =32 =77 TTL=57
Ping 77.88.21.11:
: = 4, = 4, = 0
|
|
(0% )
- :
= 77, = 1651 , = 490
3. traceroute ( Windows tracert) , IP- . , . traceroute _, . , .
traceroute (TTL) , . TTL -. .
traceroute TTL . , . , , , c , -. . , traceroute . , , . .
:
admin@ddd:~$ traceroute lenta.ru
traceroute to lenta.ru (81.19.85.92), 30 hops max, 60 byte packets
1 172.24.255.254 (172.24.255.254) 13.218 ms 14.129 ms 14.019 ms
2 84.204.14.254 (84.204.14.254) 13.848 ms 15.145 ms 15.040 ms
3 46.47.255.33 (46.47.255.33) 13.910 ms 13.815 ms 14.594 ms
4 mx960-spb.peterstar.net (82.196.95.169) 15.117 ms 25.568 ms 26.261 ms
5 ix-j-mx240.m9.ramtel.ru (193.232.244.118) 39.993 ms 39.870 ms 39.750 ms
6 s193-mx240.vr.rambler.ru (81.19.64.93) 39.672 ms 17.704 ms 19.828 ms
7 81.19.94.132 (81.19.94.132) 19.772 ms 19.708 ms 19.590 ms
8 81.19.85.92 (81.19.85.92) 19.529 ms 19.424 ms 28.634 ms
:
C:\Users\admin>tracert yandex.ru
yandex.ru [87.250.251.11]
30:
1 100 ms 104 ms 106 ms HS2-1-16.xG.SPb.SkyLink.RU [89.253.1.16]
2 119 ms 99 ms 106 ms HS2-0-1.xG.SPb.SkyLink.RU [89.253.0.1]
3 107 ms 106 ms 106 ms 212.129.96.227
4 112 ms 104 ms 106 ms aurora-spb-ix.yandex.net [194.226.100.90]
5 128 ms 198 ms 110 ms 213.180.213.134
6 * * * .
7 124 ms 108 ms 105 ms s650-eto2c1.yandex.net [213.180.213.65]
8 121 ms 132 ms 133 ms l3-s550-s650.yandex.net [213.180.213.28]
9 116 ms 106 ms 133 ms yandex.ru [87.250.251.11]
.
4. mtr (My Traceroute), traceroute ping. libncurses ( ) GTK+ ( ), , . mtr 2. mtr Linux.
|
|
.2 mtr
5. netstat TCP/IP. , , . , : , , , , . . netstat.
5.1.
netstat , / . , , . , NAT .
. , ( ), .
:
admin@ddd:~$ netstat -ta
(servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 *:29011 *:* LISTEN
tcp 0 0 localhost:ipp *:* LISTEN
tcp 0 0 172.24.0.157:35608 213.199.179.141:40041 ESTABLISHED
tcp 0 0 172.24.0.157:37760 163-247.static.quie:www TIME_WAIT
tcp 0 0 172.24.0.157:36441 95-28-49-237.broa:26647 ESTABLISHED
tcp 0 0 172.24.0.157:38541 172.24.0.170:55554 TIME_WAIT
tcp 0 0 172.24.0.157:54369 bos-w031b-rdr1.bl:https ESTABLISHED
tcp6 0 0 localhost:ipp [::]:* LISTEN
TCP. UDP .
5.2.
. , , , . , , .
, . . , , .
netstat -r .
IP-. .
:
admin@ddd:~ > netstat -r
Kernel IP routing table
Destination Gateway Genmask Flags Ifac
ddd.sut.ru * 255.255.255.255 UH eth1
195.19.219.120 * 255.255.255.248 U eth0
195.19.219.128 * 255.255.255.192 U eth1
192.168.1.0 * 255.255.255.0 U eth0
195.19.221.0 lgw.ccs.sut.ru 255.255.255.0 UG eth1
193.125.0.0 lgw.ccs.sut.ru 255.255.0.0 UG eth1
loopback * 255.0.0.0 U lo
default lgw.ccs.sut.ru 0.0.0.0 UG eth1
5.3.
- Ethernet-. , , .
:
admin@ddd:~ > netstat -
Kernel Interface table
|
|
Iface MTU Met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg
eth0 1000 0 844904 0 17 0 1454454 5 0 0 BRU
eth1 1500 0 590844 0 7 0 434438 59 0 0 BRU
lo 3924 0 45754 0 0 0 45754 0 0 0 LRU
. (RX-OVR, TX-OVR) 3% , 0,5% .
5.4.
netstat -s . , : IP, ICMP, TCP, UDP. .
:
admin@ddd:~$ netstat -s
I:
17058
2
0
0
: 4364
: 3936
Icmp:
ICMP : 306
ICMP : 0
ICMP
: 8
: 263
-: 35
ICMP: 280
ICMP: 0
ICMP
: 8
-: 14
IcmpMsg:
InType0: 35
InType3: 8
InType11: 263
OutType3: 8
OutType8: 14
OutType69: 258
Tcp:
: 148
: 0
: 4
: 2
: 0
: 3386
: 2895
: 39
: 0
: 8
Udp:
: 661
: 8
: 0
: 723
TcpExt:
, : 1
67 TCP sockets finished time wait in fast timer
: 119
69
11 packets directly queued to recvmsg prequeue.
3635 bytes directly received in process context from prequeue
: 1745
, : 5
311 acknowledgments not containing data payload received
: 299
9 congestion windows recovered without slow start after partial ack
1 timeouts in loss state
19 retransmits in slow start
TCP -: 19
22 packets collapsed in receive queue due to low socket buffer
DSACKs: 9
1 -
2 connections reset due to early user close
TCPDSACKIgnoredNoUndo: 3
TCPSackShiftFallback: 9
IpExt:
InMcastPkts: 15
OutMcastPkts: 19
InOctets: 4353792
OutOctets: 405434
InMcastOctets: 2714
OutMcastOctets: 2990
IP. IP, IPv4, IPv6. netstat , ICMP. ICMP IPv4 IPv6 , , . ICMP.
:
1. . . . .
|
|
2. : , , 5 . TTL .
3. (, , - ..). netstat , , , Ethernet. (. .1). .
:
1. , (TTL, - ..), ( ).
2. IP-.
3. , , , , netstat, , .
:
1. RFC 792 Internet control message protocol. September, 1981.
2. RFC 950 Internet Standard Subnetting Procedure. August 1985
3. RFC 4443 Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification. March, 20064. RFC 2925 Definitions of Managed Objects for Remote Ping, Traceroute, and Lookup Operations. September, 2000.
5. . ., .. . , , . 4-. , 2010.