Managing Address Forwarding Tables (Layer 2 & Layer 3)

 

 

 

 

 

 

 

Table 14-1.Address Table Instance Parameters (Continued)

 

 

 

 

 

 

Parameter

 

Definition

 

 

 

 

 

 

 

Entry Validity

 

Displays the entry validity for this VLAN.

 

 

 

 

Options include:

 

 

 

 

•

Valid - Entry exists.

 

 

 

 

•

Invalid - Entry has aged out but still exists even

 

 

 

 

 

though the port binding is invalid.

 

 

 

 

 

 

 

Hash Table

 

Displays the hash table parameters.

 

 

 

 

Options include:

 

 

 

 

•

Size - It is recommended that the hash table size be

 

 

 

 

 

1/8th the size of the total number of addresses for the

 

 

 

 

 

VLAN.

 

 

 

 

•

Auto Increment - Hash tables may grow dynamically

 

 

 

 

 

larger if more addresses are discovered. Disabling

 

 

 

 

 

auto-increment prevents these tables from growing

 

 

 

 

 

dynamically at the risk of extra flooding.

 

 

 

 

 

 

 

Bucket Info

 

Displays parameters to monitor the efficiency of the hash

 

 

 

 

table allocations.

 

 

 

 

Options include:

 

 

 

 

•

Count - Indicates the hash table count.

 

 

 

 

•

Capacity - Indicates the hash table capacity.

 

 

 

 

•

Utilization - High utilization indicates that a larger

 

 

 

 

 

hash table is needed.

 

 

 

 

 

 

 

4.From the Hash Table/Size pull-down menu, select the new size to alter the space available for this address table. The rule of thumb is: Tables with high Total Bucket Utilization (greater than 75%) can be made smaller. Tables with low Total Bucket Utilization (less than 40%) should be made larger. Note that the number of addresses for a given hash table is 4:1 (for example, if you have a hash table of 16 bytes, the VLAN can hold 64 addresses in it’s table instance.

5.From the Hash Table/Auto Increment pull-down menu, select False to prevent the table size from reconfiguring automatically.

6.Click APPLY to save your changes, or CANCEL to restore previous settings. If you want to relearn the entire table, click Delete All Learned Entries.

If you want to delete all entries that are currently aged out, click Delete All Invalid Learned Entries.

Note: If you change the Hash Table Size, the switch relearns all addresses in that table, causing the switch to flood packets for a few seconds.

Cajun P550/P220 Switch Operation Guide

14-3