Cabletron Systems SmartSwitch Router, User'S Reference Manual

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Chapter 6: IP Routing Configuration Guide
88 SmartSwitch Router User Reference Manual
• 802.3 SNAP: SNAP IEEE 802.3 encapsulation, in which the type code becomes the
frame length for the IEEE 802.2 LLC encapsulation (destination and source Service
Access Points, and a control byte)
To configure IP encapsulation, enter one of the following commands in Configure mode.
Configuring Address Resolution Protocol (ARP)
The SSR allows you to configure Address Resolution Protocol (ARP) table entries and
parameters. ARP is used to associate IP addresses with media or MAC addresses. Taking
an IP address as input, ARP determines the associated MAC address. Once a media or
MAC address is determined, the IP address/media address association is stored in an
ARP cache for rapid retrieval. Then the IP datagram is encapsulated in a link-layer frame
and sent over the network.
Configuring ARP Cache Entries
You can add and delete entries in the ARP cache. To add or delete static ARP entries, enter
one of the the following commands in Configure mode:
Configuring Proxy ARP
The SSR can be configured for proxy ARP. The SSR uses proxy ARP (as defined in
RFC 1027) to help hosts with no knowledge of routing determine the MAC address of
hosts on other networks or subnets. Through Proxy ARP, the SSR will respond to ARP
requests from a host with a ARP reply packet containing the SSR MAC address. Proxy
ARP is enabled by default on the SSR.
To disable proxy ARP, enter the following command in Configure mode:
Configure Ethernet II
encapsulation.
interface create ip
<InterfaceName>
output-mac-
encapsulation ethernet_II
Configure 802.3
SNAP encapsulation.
interface create ip
<InterfaceName>
output-mac-
encapsulation ethernet_snap
Add a static ARP entry.
arp add
<host>
mac-addr
<MAC-addr>
exit-port
<port>
Clear a static ARP entry.
arp clear
<host>
Disable Proxy ARP on
an interface.
ip disable-proxy-arp interface
<InterfaceName>
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