nx.os.and.cisco.nexus.switching.2nd.edition.1587143046

of placing constraints on a particular path for the amount of bandwidth available, the latency
of a path, or specifying an explicit primary and backup path for traffic of a particular class.
This flexibility gives administrators the ability to ensure strict SLA across different
customers and traffic characteristics.
MPLS Traffic Engineering (TE) functions by learning the topology and resources available
in a network and then mapping traffic flows to a particular path, called a label switched path
(LSP). The LSP is a unidirectional tunnel from a source MPLS node (headend) to a
destination MPLS node (tailend). The tunnel calculation uses a link-state database that
contains flooded topology, and resource information operates at the LSP headend node. This
mapping can be based on resource requirements and network resources, such as bandwidth.
One of the other concepts of MPLS TE is the capability to protect a link, a node, and even to
protect a complete end-to-end path via TE. MPLS TE uses extensions to either IS-IS or
OSPF. If configured, OSPF or IS-IS can automatically route the traffic onto the LSPs. RSVP
can be leveraged as part of MPLE TE to automatically establish and maintain the LSPs.
Finally, one interesting feature supported with NX-OS and MPLS TE is AutoBandwidth.
The AutoBandwidth feature enables traffic to be mapped to a specific LSP based on the
QoS class and policy set configured on the system. This functionality enables complete
class-based tunnel selection.
MPLS TE requires one of the IGP features (OSPF or ISIS) to be enabled. Enabling feature
mpls traffic-engineering can automatically enable other required NX-OS components
(RSVP, OAM, MPLS MGR, and ULIB).
The following is a listing of steps to configure LDP on a Nexus 7000, with examples of each
step:
1. Enable the TE feature (see Example 12-16).
2. Disable/Enable MPLS TE globally (enabled by default) (refer to Example 12-16).
3. Configure TE for the IGP (IS-IS or OSPF), as shown in Example 12-17 and Example
12-18.
Example 12-16. Enabling MPLS TE
Click here to view code image
N7k-1(config)# feature mpls traffic-engineering
N7k-1(config)# mpls traffic-eng configuration
N7k-1(config-te)# [no] shutdown
N7k-1(config)# interface loopback0
N7k-1(config-if)# ip address 1.1.1.1/32
Example 12-17. Configuring MPLS TE for IS-IS