AT-S63 Management Software Features Guide
Section VII: Routing
339
Address Resolution Protocol (ARP) Table
The switch maintains an ARP table of IP addresses and the matching
Ethernet MAC addresses. It refers to the table when routing packets to
determine the destination MAC addresses of the nodes, as well as
interfaces and ports from where the nodes are reached.
The ARP table can store both static and dynamic entries. Static entries are
entries you add yourself. This type of entry is never removed by the switch
from the ARP table, even when the corresponding nodes are inactive.
Dynamic entries are entries that the switch learns on it own. Dynamic
entries of inactive nodes are periodically removed from table to prevent the
table from filling with entries of inactive nodes.
The switch learns addresses by sending out ARP requests. It generates
an ARP request whenever it receives a packet that needs to be routed
across a subnet, but lacks the destination MAC address in its ARP table.
The switch, after receiving the ARP response from the destination node,
adds the IP address and MAC address of the node to its ARP table and
begins to route packets to the device. It should be noted that until it
receives a respond to its ARP request, the switch discards all routed
packets intended to a destination node.
The switch can also learn addresses when it is the destination of an ARP
request from another node, such as when it is pinged by a management
station. The switch adds the source IP address and MAC address in the
request from the node to the table when it responds to the ARP request.
Dynamic ARP entries are aged from the table according to the ARP cache
timeout value to protect the table from filling with entries for hosts which
are no longer active. The default setting for the timeout value is 150
seconds. This value is adjustable with the SET IP ARP TIMEOUT
command. Static ARP entries are not aged and are retained in the table
even when the nodes are inactive.
The commands for managing the ARP table are ADD IP ARP, DELETE IP
ARP, SET IP ARP, SET IP ARP TIMEOUT, and SHOW IP ARP.
Note
The switch does not support Proxy ARP.
The storage capacity of the ARP table in the AT-9400 Switch is:
1024 static entries
1024 dynamic entries
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 ...