HP Network Direr Software Products manual Network Topology Example

572CHAPTER 13: VLAN MANAGEMENT

Figure 312 Network Topology Example (2)

Note that the links from the layer 2 switches to the 4007 layer 3 switch have been lost and each end-station is shown connected to both a layer 2 switch and the 4007. This is a known limitation of 3Com Network Director. The work around is to discover all subnets within the one discovery operation.

Spanning Tree 3Com Network Director does not support networks where there is a separate Spanning Tree domain for each VLAN. 3Com Network Director may not represent the topology of such networks correctly. In general, 3Com switches only support one Spanning Tree domain.

Problems with In order for 3Com Network Director to construct its map of the network, apparent network it reads the Bridge Forwarding Table from each of the switches on the

loops network. This table tells 3Com Network Director which ports on a switch have learned which MAC addresses. After gathering this information from all switches, 3Com Network Director can work out how the various devices on the network are connected together.

Switches with VLANs configured typically have a Bridge Forwarding Table per VLAN. 3Com Network Director reads these per-VLAN Bridge Forwarding Tables. However, in some circumstances, a MAC address can