Sub-Interface; Introduction To Sub-Interface; Configuring An Ethernet Sub-Interface - 3Com MSR 50 Series Configuration Manual

Sub-interface

Introduction to
Sub-interface
Configuring an Ethernet
Sub-interface
Table 22 Configure a null interface
Operation
Enter null interface view interface null 0
Sub-interfaces are logical virtual interfaces configured on a primary interface. The
primary interface can be either a physical interface (such as a layer-3 Ethernet
interface) or a logical interface (such as an MFR interface). A sub-interface can
share the physical-layer parameters of the primary interface and also have its own
link-layer and network-layer parameters configured. Disabling or enabling an
sub-interface has no effect on the corresponding primary interface, but state
changes of the primary interface affect the sub-interfaces. A sub-interface can
operate properly only when the primary interface operates properly.
With the sub-interface feature enabled, you can configure multiple sub-interfaces
for a single physical interface of a device, thus improving the flexibility of
networking implementation.
The following physical interfaces support sub-interfaces:
Ethernet interfaces. With a VLAN ID configured for an Ethernet sub-interface,
■
the sub-interface supports IPX; with a VLAN ID configured for an Ethernet
sub-interface, the sub-interface supports both IPX and IP at the same time.
WAN interfaces with their data link layer protocols being frame relay, whose
■
sub-interfaces support IP and IPX.
WAN interfaces with their data link layer protocols being X.25, whose
■
sub-interfaces support IP and IPX.
ATM interfaces, whose sub-interfaces support only IP.
■
Configure operation parameters for an Ethernet sub-interface
An Ethernet sub-interface can solve the problem that layer-3 Ethernet interfaces
cannot identify VLAN packets.
Through configuring multiple sub-interfaces on an Ethernet interface and setting
the encapsulation type and associated VLAN for each sub-interface. You can have
packets of different VLANs forwarded on different sub-interfaces, thus improving
the flexibility of networking implementations.
Table 23 Configure an Ethernet sub-interfaces
Operation
Enter system view
Command Description
Required
By default, null interface 0 is existing on a
device and can neither be created nor
removed.
Command
system-view
Sub-interface 527
Description
-