Chapter 29: Internet Protocol Version 4 Packet Routing
340
Section VII: Routing
Internet Control Message Protocol (ICMP)
ICMP allows routers to send error and control messages to other routers
or hosts. It provides the communication between IP software on one
system and IP software on another. The switch implements the ICMP
functions listed in Table 94.
Table 94. ICMP Messages Implemented on the AT-9400 Switch
ICMP Packet (Type)
Switch Response
Echo reply (0)
This is used to implement the
“ping” command common to most
UNIX and TCP implementations.
The switch sends out an “Echo
reply” packet in response to an
“Echo request.”
Destination unreachable (3)
This message is sent out when the
switch drops a packet because it
did not have a route to the
destination.
Source Quench (4)
The switch will send a “Source
Quench” if it must drop a packet
due to limited internal resources.
This could be because the source
was sending data too fast to be
forwarded.
Redirect (5)
The switch will issue a “redirect”
packet to inform a local host that
its target is located on the same
LAN (no routing is required) or
when it detects a host using a non-
optimal route (usually because a
link has failed or changed its
status).
Echo request (8)
This is related to (1) and results in
an “echo reply” packet being sent.
The switch can also generate an
“echo request” packet as a result
of the PING command.
Содержание AT-S63
Страница 14: ...Figures 14 ...
Страница 18: ...Tables 18 ...
Страница 28: ...28 Section I Basic Operations ...
Страница 58: ...Chapter 1 Overview 58 ...
Страница 76: ...Chapter 2 AT 9400Ts Stacks 76 Section I Basic Operations ...
Страница 96: ...Chapter 5 MAC Address Table 96 Section I Basic Operations ...
Страница 114: ...Chapter 8 Port Mirror 114 Section I Basic Operations ...
Страница 116: ...116 Section II Advanced Operations ...
Страница 146: ...Chapter 12 Access Control Lists 146 Section II Advanced Operations ...
Страница 176: ...Chapter 14 Quality of Service 176 Section II Advanced Operations ...
Страница 196: ...196 Section III Snooping Protocols ...
Страница 204: ...Chapter 18 Multicast Listener Discovery Snooping 204 Section III Snooping Protocols ...
Страница 216: ...Chapter 20 Ethernet Protection Switching Ring Snooping 216 Section III Snooping Protocols ...
Страница 218: ...218 Section IV SNMPv3 ...
Страница 234: ...234 Section V Spanning Tree Protocols ...
Страница 268: ...268 Section VI Virtual LANs ...
Страница 306: ...Chapter 27 Protected Ports VLANs 306 Section VI Virtual LANs ...
Страница 320: ...320 Section VII Internet Protocol Routing ...
Страница 360: ...Chapter 30 BOOTP Relay Agent 360 Section VII Routing ...
Страница 370: ...Chapter 31 Virtual Router Redundancy Protocol 370 Section VII Routing ...
Страница 372: ...372 Section VIII Port Security ...
Страница 402: ...Chapter 33 802 1x Port based Network Access Control 402 Section VIII Port Security ...
Страница 404: ...404 Section IX Management Security ...
Страница 436: ...Chapter 36 PKI Certificates and SSL 436 Section IX Management Security ...
Страница 454: ...Chapter 38 TACACS and RADIUS Protocols 454 Section IX Management Security ...
Страница 462: ...Chapter 39 Management Access Control List 462 Section IX Management Security ...
Страница 504: ...Appendix B SNMPv3 Configuration Examples 504 Security Model Security Level Storage Type SNMPv3 Parameters Continued ...
Страница 532: ...Appendix D MIB Objects 532 ...