[R1] f0/0 ------------------------------ f1/1 [R2]
[R1]
int f0/0
ip add 150.1.1.1 255.255.255.0
ip access-list extended ICMP
permit icmp and and
class-map ICMP
match access-group name ICMP
policy-map ICMP
class ICMP
control-plane
service-policy input ICMP
#deb ip packet detail
#sh policy-map control-plane
Control Plane
Service-policy input: ICMP
Class-map: ICMP (match-all)
0 packets, 0 bytes
5 minute offered rate 0 bps
Match: access-group name ICMP
Class-map: class-default (match-any)
0 packets, 0 bytes
5 minute offered rate 0 bps, drop rate 0 bps
Match: any
R1#ping 150.1.1.1 re 1 <----- ping count 1
Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 150.1.1.1, timeout is 2 seconds:
!
Success rate is 100 percent (1/1), round-trip min/avg/max = 1/1/1 ms
R1#
00:12:24: IP: s=150.1.1.1 (local), d=150.1.1.1 (FastEthernet0/0), len
100, sending
00:12:24: ICMP type=8, code=0
00:12:24: IP: s=150.1.1.1 (FastEthernet0/0), d=150.1.1.1, len 100, rcvd 2
00:12:24: ICMP type=8, code=0
00:12:24: IP: s=150.1.1.1 (FastEthernet0/0), d=150.1.1.1, len 100, stop
process pak for forus packet
00:12:24: ICMP type=8, code=0
00:12:24: IP: s=150.1.1.1 (local), d=150.1.1.1 (FastEthernet0/0), len
100, sending
00:12:24: ICMP type=0, code=0
00:12:24: IP: s=150.1.1.1 (FastEthernet0/0), d=150.1.1.1, len 100, rcvd 2
00:12:24: ICMP type=0, code=0
00:12:24: IP: s=150.1.1.1 (FastEthernet0/0), d=150.1.1.1
R1#, len 100, stop process pak for forus packet
00:12:24: ICMP type=0, code=0
R1#sh policy-map control-plane
Control Plane
Service-policy input: ICMP
Class-map: ICMP (match-all)
2 packets, 228 bytes <---- สังเกตุว่าเมื่อแสดง log พบว่า match
icmp 2 packet ทั้งๆที่เรา ping count = 1
5 minute offered rate 0 bps
Match: access-group name ICMP
Class-map: class-default (match-any)
0 packets, 0 bytes
5 minute offered rate 0 bps, drop rate 0 bps
Match: any
เมื่อเราใช้ ethereal จับ packet ดู
No. Time Source Destination Protocol
Info
1 0.000000 ca:00:1c:34:00:00 ca:00:1c:34:00:00 LOOP
Reply
Frame 1 (60 bytes on wire, 60 bytes captured)
Arrival Time: Feb 27, 2008 10:26:20.228782000
[Time delta from previous captured frame: 0.000000000 seconds]
[Time delta from previous displayed frame: 0.000000000 seconds]
[Time since reference or first frame: 0.000000000 seconds]
Frame Number: 1
Frame Length: 60 bytes
Capture Length: 60 bytes
[Frame is marked: False]
[Protocols in frame: eth:loop:data]
Ethernet II, Src: ca:00:1c:34:00:00 (ca:00:1c:34:00:00), Dst:
ca:00:1c:34:00:00 (ca:00:1c:34:00:00)
Destination: ca:00:1c:34:00:00 (ca:00:1c:34:00:00)
Address: ca:00:1c:34:00:00 (ca:00:1c:34:00:00)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
.... ..1. .... .... .... .... = LG bit: Locally administered
address (this is NOT the factory default)
Source: ca:00:1c:34:00:00 (ca:00:1c:34:00:00)
Address: ca:00:1c:34:00:00 (ca:00:1c:34:00:00)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
.... ..1. .... .... .... .... = LG bit: Locally administered
address (this is NOT the factory default)
Type: Loopback (0x9000)
Configuration Test Protocol (loopback)
skipCount: 0
Relevant function:
Function: Reply (1)
Receipt number: 0
Data (40 bytes)
0000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0020 00 00 00 00 00 00 00 00 ........
No. Time Source Destination Protocol
Info
3 9.987619 ca:00:1c:34:00:00 ca:00:1c:34:00:00 LOOP
Reply
Frame 3 (60 bytes on wire, 60 bytes captured)
Arrival Time: Feb 27, 2008 10:26:30.216401000
[Time delta from previous captured frame: 2.968997000 seconds]
[Time delta from previous displayed frame: 2.968997000 seconds]
[Time since reference or first frame: 9.987619000 seconds]
Frame Number: 3
Frame Length: 60 bytes
Capture Length: 60 bytes
[Frame is marked: False]
[Protocols in frame: eth:loop:data]
Ethernet II, Src: ca:00:1c:34:00:00 (ca:00:1c:34:00:00), Dst:
ca:00:1c:34:00:00 (ca:00:1c:34:00:00)
Destination: ca:00:1c:34:00:00 (ca:00:1c:34:00:00)
Address: ca:00:1c:34:00:00 (ca:00:1c:34:00:00)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
.... ..1. .... .... .... .... = LG bit: Locally administered
address (this is NOT the factory default)
Source: ca:00:1c:34:00:00 (ca:00:1c:34:00:00)
Address: ca:00:1c:34:00:00 (ca:00:1c:34:00:00)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
.... ..1. .... .... .... .... = LG bit: Locally administered
address (this is NOT the factory default)
Type: Loopback (0x9000)
Configuration Test Protocol (loopback)
skipCount: 0
Relevant function:
Function: Reply (1)
Receipt number: 0
Data (40 bytes)
0000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0020 00 00 00 00 00 00 00 00 ........
พบว่ามันเป็น protocol LOOP ผมเลยไปค้นหาจาก wiki.wireshark.org
h**p://wiki.wireshark.org/Loop?action=show&redirect=Protocols%2Floop
