Technical data

Using Technician Interface Software

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303561-A Rev 00

• ARP processing -- The packet has been held and an ARP request packet has

been sent to the LAN for that host. When the address is resolved, the cache

entry for this host is flushed (deleted) and the packet is forwarded.

• Multicast processing -- The packet will be handled using information from the

multicast cache. (More information follows on the multicast cache.)

The internal cache is limited in size, and operates on a first in first out (FIFO)

basis. For this reason, cache entries (routes) also have a finite lifetime dictated

largely by the size (depth) of the internal cache. The larger the size of the internal

cache, the longer it takes for an entry in that cache to expire.

With the

ip command, you can examine the entire contents of the cache for a

specific logical interface configured on the router. To view the cache for any

interface configured on the router, enter the

ip command using the following

syntax:

ip cache

<interface_address>

is the IP address of the logical interface associated with the

interface cache you want to examine.

Multicast Cache

If you enable a multicast protocol on a circuit, the system allocates and maintains

one multicast cache for that circuit. Each entry in a multicast cache entry identifies

the hosts (sources) and multicast groups from which the local circuit is receiving

multicast traffic.

With the

ip command, you can examine the entire contents of the multicast cache

for a specific physical circuit. To view the multicast cache for any circuit

configured on the router, enter the

ip command using the following syntax:

ip cache -M

<interface_address>

is the IP address of the logical interface associated with the

multicast cache you want to examine.