Autotunnel Attribute-Set; Link Protection; Node Protection - Cisco ASR 9000 Series Configuration Manual

MPLS Traffic Engineering

AutoTunnel Attribute-set

This feature supports auto-tunnels configuration using attribute templates, known as attribute-set. The TE
attribute-set template that specifies a set of TE tunnel attributes, is locally configured at the head-end of
auto-tunnels. The control plane triggers the automatic provisioning of a corresponding TE tunnel, whose
characteristics are specified in the respective attribute-set.
Currently, auto-tunnel backups are created with the default values of all tunnel attributes. To support
configurable attributes for auto-tunnel backup, it is required to configure attribute-set and assign it to the
backup tunnels. The attribute-set consists of a set of tunnel attributes such as priority, affinity, signaled
bandwidth, logging, policy-class, record-route and so on.
The following rules (consistent across all auto-tunnels) apply while configuring the attribute-set:
• If no attribute-set template is defined, the auto-tunnels is created using default attribute values.
• If an attribute-set is defined and the attribute-set template is already configured, the auto-tunnel is created
using the attributes specified in the associated attribute-set.
• If an attribute-set is assigned, but it is not defined or configured, auto-tunnel is not created.
• Any number of attribute-sets can be configured with same attribute settings.
• Empty tunnel attribute implies all parameters have default values.
• When specific attribute is not specified in the attribute-set, a default value for that attribute is used.

Link Protection

The backup tunnels that bypass only a single link of the LSP path provide link protection. They protect LSPs,
if a link along their path fails, by rerouting the LSP traffic to the next hop, thereby bypassing the failed link.
These are referred to as NHOP backup tunnels because they terminate at the LSP's next hop beyond the point
of failure.
This figure illustrates link protection.
Figure 10: Link Protection

Node Protection

The backup tunnels that bypass next-hop nodes along LSP paths are called NNHOP backup tunnels because
they terminate at the node following the next-hop node of the LSPs, thereby bypassing the next-hop node.
Cisco ASR 9000 Series Aggregation Services Router MPLS Configuration Guide, Release 4.3.x
118
Implementing MPLS Traffic Engineering
OL-28381-02