Create Sub-Interfaces¶
This command is used to add VLAN IDs to interfaces, also known as subinterfaces. The primary input to this command is the ‘interface’ and ‘subId’ (subinterface Id) parameters. If no additional VLAN ID is provide, the VLAN ID is assumed to be the ‘subId’. The VLAN ID and ‘subId’ can be different, but this is not recommended.
This command has several variations:
- create sub-interfaces <interface> <subId> - Create a subinterface to process packets with a given 802.1q VLAN ID (same value as the ‘subId’).
- create sub-interfaces <interface> <subId> default - Adding the ‘default’ parameter indicates that packets with VLAN IDs that do not match any other subinterfaces should be sent to this subinterface.
- create sub-interfaces <interface> <subId> untagged - Adding the ‘untagged’ parameter indicates that packets no VLAN IDs should be sent to this subinterface.
- create sub-interfaces <interface> <subId>-<subId> - Create a range of subinterfaces to handle a range of VLAN IDs.
- create sub-interfaces <interface> <subId> dot1q|dot1ad <vlanId>|any [exact-match] - Use this command to specify the outer VLAN ID, to either be explicited or to make the VLAN ID different from the ‘subId’.
- create sub-interfaces <interface> <subId> dot1q|dot1ad <vlanId>|any inner-dot1q <vlanId>|any [exact-match] - Use this command to specify the outer VLAN ID and the innner VLAN ID.
When ‘dot1q’ or ‘dot1ad’ is explictly entered, subinterfaces can be configured as either exact-match or non-exact match. Non-exact match is the CLI default. If ‘exact-match’ is specified, packets must have the same number of VLAN tags as the configuration. For non-exact-match, packets must at least that number of tags. L3 (routed) interfaces must be configured as exact-match. L2 interfaces are typically configured as non-exact-match. If ‘dot1q’ or ‘dot1ad’ is NOT entered, then the default behavior is exact-match.
Use the ‘show interface’ command to display all subinterfaces.
Summary/Usage¶
create sub-interfaces <interface> {<subId> [default|untagged]} | {<subId>-<subId>} | {<subId> dot1q|dot1ad <vlanId>|any [inner-dot1q <vlanId>|any] [exact-match]}.
Examples¶
Example of how to create a VLAN subinterface 11 to process packets on 802.1q VLAN ID 11:
vpp# create sub-interfaces GigabitEthernet2/0/0 11
The previous example is shorthand and is equivalent to:
vpp# create sub-interfaces GigabitEthernet2/0/0 11 dot1q 11 exact-match
Example of how to create a subinterface number that is different from the VLAN ID:
vpp# create sub-interfaces GigabitEthernet2/0/0 11 dot1q 100
Examples of how to create q-in-q and q-in-any subinterfaces:
vpp# create sub-interfaces GigabitEthernet2/0/0 11 dot1q 100 inner-dot1q 200
vpp# create sub-interfaces GigabitEthernet2/0/0 12 dot1q 100 inner-dot1q any
Examples of how to create dot1ad interfaces:
vpp# create sub-interfaces GigabitEthernet2/0/0 11 dot1ad 11
vpp# create sub-interfaces GigabitEthernet2/0/0 12 dot1ad 100 inner-dot1q 200
Examples of ‘exact-match’ versus non-exact match. A packet with outer VLAN 100 and inner VLAN 200 would match this interface, because the default is non-exact match:
vpp# create sub-interfaces GigabitEthernet2/0/0 5 dot1q 100
However, the same packet would NOT match this interface because ‘exact-match’ is specified and only one VLAN is configured, but packet contains two VLANs:
vpp# create sub-interfaces GigabitEthernet2/0/0 5 dot1q 100 exact-match
Example of how to created a subinterface to process untagged packets:
vpp# create sub-interfaces GigabitEthernet2/0/0 5 untagged
Example of how to created a subinterface to process any packet with a VLAN ID that does not match any other subinterface:
vpp# create sub-interfaces GigabitEthernet2/0/0 7 default
When subinterfaces are created, they are in the down state. Example of how to enable a newly created subinterface:
vpp# set interface GigabitEthernet2/0/0.7 up