Auto tunnel design considerations

General Information

The following applies to the configuration of auto tunnels:

• An NFM-P operator requires topology-management privileges to create or modify an auto tunnel.

• When an NE in a rule-based group is unmanaged or deleted, it is identified as unmanaged in the rule-based group. Auto tunnels to the NE are not removed; however auto tunnels from the NE are removed from the NFM-P.

• When an auto tunnel rule is created for a group that contains non-NFM-P-managed NEs, auto tunnels cannot be created to and from the NE using that rule.

• When you add NEs to a tunnel group that is in use, new auto tunnels are created according to the rule definition.

• A group condition must contain at least one group of NEs.

• Auto tunnel elements are not updated dynamically.

• An unmanaged NE is removed from the tunnel groups to which the NE belongs. The associated service tunnels are also removed if they originate from a managed NE. A service tunnel that originates on an unmanaged NE is retained, but is not included in the tunnel group after reconfiguration.

• When a service tunnel created by a tunnel policy is removed, the policy does not attempt to recreate the tunnel.

• You can modify the tunnel definition in a tunnel policy when the tunnel policy has not yet created a service tunnel.

Not all NEs that are assigned to a topology rule share the same functionality. The topology rule runs capability checks on the source NEs to determine whether specific tunnels or tunnel configurations can be applied. The following table lists the auto tunnel rules that are supported by each NE.

Table 56-1: Auto tunnel rules and NE support

Auto tunnel rule	7450 ESS, 7750 SR, and 7950 XRS	7705 SAR
SDP LDP	X	X
SDP GRE	X	X
SDP LSP	X	X
Dynamic LSP	X	X
CoS-based SDP	X	—
LDP-over-RSVP	X	—