Allow L2 mode on a Citrix ADC instance
In Layer 2 (L2) mode, a Citrix ADC instance acts as a learning bridge and forwards all packets for which it is not the destination. Some features, such as Citrix CloudBridge, require that L2 mode be enabled on the Citrix ADC instance. With L2 mode enabled, the instance can receive and forward packets for MAC addresses other than its own MAC address. However, to enable L2 mode on a Citrix ADC instance running on a Citrix ADC SDX appliance, the administrator must first allow L2 mode on that instance. If you allow L2 mode, you must take precautions to avoid bridging loops.
On a given 1/x interface, untagged packets must be allowed on only one instance. For all other instances enabled on the same interface, you must select Tagged.
Citrix recommends that you select Tagged for all interfaces assigned to instances in L2 mode. If you select tagged, you cannot receive untagged packets on that interface.
If you have selected Tagged for an interface assigned to an instance, log on to that instance and configure a 802.1q VLAN to receive packets on that interface.
For 1/x and 10/x interfaces that are shared by Citrix ADC instances on which L2 mode is allowed, make sure that the following conditions are met:
- VLAN filtering is enabled on all the interfaces.
- Each interface is on a different 802.1q VLAN.
- Only one instance can receive untagged packets on the interface. If that interface is assigned to other instances, you must select Tagged on that interface for those instances.
If you allow untagged packets on a 1/x interface for an instance on which L2 mode is allowed, no other instance can receive untagged packets on that interface. This condition applies irrespective of whether L2 mode allowed or disallowed on the other instance.
If you allow untagged packets on a 1/x interface for an instance with L2 mode disabled, an instance with L2 mode allowed cannot receive untagged packets on that interface.
If a 0/x interface is assigned to instance1 provisioned in L2 mode, and that interface is also assigned to instance2, select Tagged for all other interfaces assigned to instance2.
Note: If both management interfaces are assigned to an instance with L2 mode, only one of these interfaces can be assigned to another ADC instance with L2 mode enabled. That is, you cannot associate both management interfaces with more than one Citrix ADC instance on which L2 mode is enabled.
To allow L2 mode on an instance
- In the Provision ADC Wizard or the Modify ADC Wizard, on the Network Settings page, select Allow L2 Mode. Note: You can activate the Allow L2 Mode setting on an instance when you provision the instance, or while the instance is running.
- Follow the instructions in the wizard.
- Click Finish, and then click Close.