Dell BigIron RX Series, Configuration Manual

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308 BigIron RX Series Configuration Guide
53-1002253-01
Configuring 802.1q-in-q tagging
11
As shown in Figure 25 , the ports to customer interfaces are untagged, whereas the uplink ports to
the provider cloud are tagged, because multiple client VLANs share the uplink to the provider cloud.
In this example, the device treats the customer’s private VLAN ID and 8100 tag type as normal
payload, and adds the 9100 tag type to the packet when the packet is sent to the uplink and
forwarded along the provider cloud.
As long as the switches in the provider’s network support the 9100 tag type, the data gets switched
along the network. However, devices that do not support the 9100 tag type may not properly
handle the packets.
Figure 26 shows an example application of the 802.1Q-in-Q enhancement.
FIGURE 26 802.1Q-in-Q configuration example
In Figure 26 , the untagged ports (to customer interfaces) accept frames that have any 802.1Q
tag other than the configured tag-type 9100. These packets are considered untagged on this
incoming port and are re-tagged when they are sent out of the uplink towards the provider. The
802.1Q tag-type on the uplink port is 8100, so the device will switch the frames to the uplink
device with an additional 8100 tag, thereby supporting devices that only support this method
of VLAN tagging.
Configuration rules
Follow the rules below when configuring 802.1q-in-q tagging:
•
Since the uplink (to the provider cloud) and the edge link (to the customer port) must have
different 802.1Q tags, make sure the uplink and edge link are in different port regions.
•
If you configure a port with an 802.1Q tag-type, the device automatically applies the 802.1Q
tag-type to all ports within the same port region.
•
If you remove the 802.1Q tag-type from a port, the device automatically removes the 802.1Q
tag-type from all ports within the same port region.
•
The device supports on configured tag-type per device, along with the default tag-type of 8100.
For example, if you configure an 802.1Q tag of 9100 on ports 1 – 8, then later configure an
802.1Q tag of 5100 on port 9, the device automatically applies the 5100 tag to all ports in the
same port region as port 9, and also changes the 802.1Q tag-type on ports 1 – 8 to 5100.
To customer interface
Provider
Edge Switch
Uplink to provider cloud
Untagged
Tagged
DA
SA 8100
Customer
VLAN
DA SA 8100
Customer
VLAN
Provider
VLAN
8100
Configured tag-type 9100
Default tag-type 8100