Figure 3-13
Networking diagram of Layer 2 communications between a sub-VLAN and
an external network
RouterA
VLAN 3
VLAN 2
Super VLAN 10
VLANIF10:10.1.1.1/24
Host A
10.1.1.2/24
Host B
10.1.1.3/24
Eth2/0/1
Eth2/0/2
RouterB
Eth2/0/3
Eth2/0/1
VLAN Trunk all
VLAN Trunk all
The frame that accesses RouterA through Port1 on Host A is tagged with the ID of VLAN
2. The VLAN ID, however, is not changed to the ID of VLAN 10 on RouterA even if VLAN
2 is the sub-VLAN of VLAN 10. After passing through Port3, which is the trunk type, this
frame still carries the ID of VLAN 2.
That is to say, RouterA itself does not send the frames of VLAN 10. In addition,
RouterA discards the frames of VLAN 10 that are sent to RouterA by other devices because
RouterA has no corresponding physical port for VLAN 10.
A super-VLAN has no physical port. This limitation is obligatory, as shown below:
–
If you configure the super-VLAN and then the trunk interface, the frames of a super-
VLAN are filtered automatically according to the VLAN range set on the trunk interface.
As shown in
, no frame of the super-VLAN 10 passes through Port3 on
RouterA, even though the interface allows frames from all VLANs to pass through.
–
If you finish configuring the trunk interface and allow all VLANs to pass through, you
still cannot configure the super-VLAN on RouterA. The root cause is that any VLAN
with physical ports cannot be configured as the super-VLAN, and the trunk interface
allows only the frames tagged with VLAN IDs to pass through. Therefore, no VLAN
can be configured as a super-VLAN.
As for RouterA, the valid VLANs are just VLAN 2 and VLAN 3, and all frames are
forwarded in these VLANs.
l
Layer 3 Communications Between a Sub-VLAN and an External Network
Huawei AR530&AR550 Series Industrial Switch Routers
Configuration Guide - Ethernet Switching
3 VLAN Configuration
Issue 01 (2014-11-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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