3Com 3C15500 - Network Director User Manual page 515

Key Concepts 511
Figure 264 VLAN Matching by 3Com Network Director
3Com Network Director would not consider these as two different VLANs
and would instead work out that the VLANs are equivalent. 3Com
Network Director will only consider a VLAN configured on one switch to
be the same as a VLAN on another switch if they have the same VLAN ID,
and are connected by a link that has the VLAN configured on the ports at
each end.
These rules are intentionally simple, to ensure that the user can easily
deduce how 3Com Network Director has presented their network. Rather
than attempting to second guess what the user may have intended,
3Com Network Director presents any inconsistencies as
misconfigurations. See "Misconfigurations and Optimizations Report" on
page 534.