Reference Guide
Tracing the route to www.force10networks.com (10.11.84.18), 30 hops max, 40
byte packets
----------------------------------------------------------------------
TTL Hostname Probe1 Probe2 Probe3
1 10.11.199.190 001.000 ms 001.000 ms 002.000 ms
2 gwegress-sjc-02.force10networks.com (10.11.30.126) 005.000 ms 001.000 ms
001.000 ms
3 fw-sjc-01.force10networks.com (10.11.127.254) 000.000 ms 000.000 ms 000.000
ms
4 www.dell.com (10.11.84.18) 000.000 ms 000.000 ms 000.000 ms
FTOS#
ARP
FTOS uses two forms of address resolution: address resolution protocol (ARP) and Proxy ARP.
ARP runs over Ethernet and enables endstations to learn the MAC addresses of neighbors on an IP network. Over time,
FTOS creates a forwarding table mapping the MAC addresses to their corresponding IP address. This table is called the
ARP Cache and dynamically learned addresses are removed after a defined period of time.
For more information about ARP, refer to RFC 826,
An Ethernet Address Resolution Protocol
.
In FTOS, Proxy ARP enables hosts with knowledge of the network to accept and forward packets from hosts that contain
no knowledge of the network. Proxy ARP makes it possible for hosts to be ignorant of the network, including subnetting.
For more information about Proxy ARP, refer to RFC 925,
Multi-LAN Address Resolution
, and RFC 1027,
Using ARP to
Implement Transparent Subnet Gateways
.
Configuration Tasks for ARP
For a complete listing of all ARP-related commands, refer to the
FTOS Command Line Reference Guide
.
Configuration tasks for ARP include:
• Configuring Static ARP Entries (optional)
• Enabling Proxy ARP (optional)
• Clearing ARP Cache (optional)
• ARP Learning via Gratuitous ARP
• ARP Learning via ARP Request
• Configuring ARP Retries
Configuring Static ARP Entries
ARP dynamically maps the MAC and IP addresses, and while most network host support dynamic mapping, you can
configure an ARP entry (called a static ARP) for the ARP cache.
To configure a static ARP entry, use the following command.
• Configure an IP address and MAC address mapping for an interface.
CONFIGURATION mode
arp ip-address mac-address interface
– ip-address: IP address in dotted decimal format (A.B.C.D).
– mac-address: MAC address in nnnn.nnnn.nnnn format.
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