2-10
Static Virtual LANs (VLANs)
Port-Based Virtual LANs (Static VLANs)
showing the (different) source VLAN and source port. Other switch models
have a single-forwarding database, which means they allow only one data-
base entry of a unique MAC address, along with the source VLAN and source
port on which it is found (see Table 2-6). Not all VLANs on a switch covered
by this guide use the same MAC address (see “VLAN MAC Addresses” on page
2-35). Connecting multiple-forwarding database switch to a single-forwarding
database switch where multiple VLANs exist imposes some cabling and port
VLAN assignment restrictions. Table 2-6 illustrates the functional difference
between the two database types.
Table 2-6. Example of Forwarding Database Content
Table 2-7 lists the database structure of current ProCurve switch models.
Table 2-7. Forwarding Database Structure for Managed ProCurve Switches
Multiple-Forwarding Database Single-Forwarding Database
MAC Address Destination
VLAN ID
Destination
Port
MAC Address Destination
VLAN ID
Destination
Port
0004ea-84d9f4 1 A5 0004ea-84d9f4 100 A9
0004ea-84d9f4 22 A12 0060b0-880af9 105 A10
0004ea-84d9f4 44 A20 0060b0-880a81 107 A17
0060b0-880a81 33 A20
This database allows multiple destinations
for the same MAC address. If the switch
detects a new destination for an existing
MAC entry, it just adds a new instance of that
MAC to the table.
This database allows only one destination
for a MAC address. If the switch detects a
new destination for an existing MAC entry,
it replaces the existing MAC instance with
a new instance showing the new
destination.
Multiple-Forwarding Databases* Single-Forwarding Database*
Switch 6108 Switch 1600M/2400M/2424M
Series 5300xl switches Switch 4000M/8000M
Series 4100gl switches Series 2500 switches
Series 3400cl switches Switch 800T
Switch 2810 Switch 2000
Series 2800 switches x
Series 2600/2600-PWR switches
*To determine whether other vendors’ devices use single-forwarding
or multiple-forwarding database architectures, refer to the
documentation provided for those devices.