Example Of Network-Based Vlans - 3Com corebuilder 3500 Implementation Manual

Figure 33 shows two network-based IP VLAN interfaces. The IPVLAN2
Example of
Network-based interface includes trunk ports and defines the protocol type IP, a Layer 3
VLANs address, a subnet mask, and IEEE 802.1Q tagging on bridge ports 6 and 7
(the anchor port for the trunk that uses ports 7 and 8). The IPVLAN3
interface defines IP and a different Layer 3 address; it uses exactly the
same ports as IP VLAN2, with IEEE 802.1Q tagging on bridge ports 6
and 7.
You can define only one IP routing interface for a network-based
VLAN. When you define an IP routing interface with the interface type
vlan, the system does not allow you to select a network-based IP
VLAN that already has a routing interface defined for it. For more
information about IP routing interfaces, see Chapter 11.
If you define multiple interfaces for an IP VLAN (instead of defining a
network-based VLAN), you cannot subsequently modify that IP VLAN
to supply Layer 3 address information. If only one routing interface is
defined for the IP VLAN, then you can supply Layer 3 address
information as long as it matches the Layer 3 information specified for
the routing interface.
In allClosed VLAN mode, you must supply IEEE 802.1Q tagging for any
overlapped ports. Therefore, this feature has no added benefit. When
IEEE 802.1Q tagging is implemented, implicit VLAN membership
information such as the protocol or Layer 3 IP network address is not
used; the frame is assigned to the VLAN based solely on the tag VID
and the receive port.
In allOpen mode, you are not required to supply the IEEE 802.1Q
tagging. To ensure line-speed throughput for overlapped
network-based IP VLANs in allOpen mode, however, you should still
supply the IEEE 802.1Q tagging.
Network-based IP VLANs 193