ProCurve 2610-PWR Technical Information download pdf (Page 38)

Static Virtual LANs (VLANs)

Port-Based Virtual LANs (Static VLANs)

Series 2600/2600-PWR switches

Multiple-Forwarding Databases* Single-Forwarding Database*

Series 2510 switches

*To determine whether other vendors’ devices use single-forwarding

or multiple-forwarding database architectures, refer to the

documentation provided for those devices.

Single-Forwarding Database Operation

When a packet arrives with a destination MAC address that matches a MAC

address in the switch’s forwarding table, the switch tries to send the packet

to the port listed for that MAC address. But, if the destination port is in a

different VLAN than the VLAN on which the packet was received, the switch

drops the packet. This is not a problem for a switch with a multiple-forwarding

database (refer to table 2-7, above) because the switch allows multiple

instances of a given MAC address; one for each valid destination. However, a

switch with a single-forwarding database allows only one instance of a given

MAC address. If (1) you connect the two types of switches through multiple

ports or trunks belonging to different VLANs, and (2) enable routing on the

switch having the multiple-forwarding database; then, on the switch having

the single-forwarding database, the port and VLAN record it maintains for the

connected multiple-forwarding-database switch can frequently change. This

causes poor performance and the appearance of an intermittent or broken

connection.

Example of an Unsupported Configuration and How

to Correct It

The Problem. In figure 2-8, the MAC address table for Switch 8000M will

sometimes record the multiple-forwarding database switch as accessed on

port A1 (VLAN 1), and other times as accessed on port B1 (VLAN 2):

2-12

1 2 ... 33 34 35 36 37 38 39 40 41 42 43 ... 363 364

No comments

ProCurve 2610-PWR Technical Information Page 38