Mpls Traffic Engineering Shared Risk Link Groups; Explicit Path - Cisco ASR 9000 Series Configuration Manual

Implementing MPLS Traffic Engineering
Point-to-Multipoint Traffic-Engineering Overview, on page 140
Point-to-Multipoint RSVP-TE , on page 142

MPLS Traffic Engineering Shared Risk Link Groups

Shared Risk Link Groups (SRLG) in MPLS traffic engineering refer to situations in which links in a network
share a common fiber (or a common physical attribute). These links have a shared risk, and that is when one
link fails, other links in the group might fail too.
OSPF and Intermediate System-to-Intermediate System (IS-IS) flood the SRLG value information (including
other TE link attributes such as bandwidth availability and affinity) using a sub-type length value (sub-TLV),
so that all routers in the network have the SRLG information for each link.
To activate the SRLG feature, configure the SRLG value of each link that has a shared risk with another link.
A maximum of 30 SRLGs per interface is allowed. You can configure this feature on multiple interfaces
including the bundle interface.
Figure 16: Shared Risk Link Group
Figure 16: Shared Risk Link Group
Related Topics
Configuring the SRLG Values of Each Link that has a Shared Risk with Another Link, on page 212
Creating an Explicit Path With Exclude SRLG, on page 214
Using Explicit Path With Exclude SRLG, on page 216
Creating a Link Protection on Backup Tunnel with SRLG Constraint, on page 218
Creating a Node Protection on Backup Tunnel with SRLG Constraint, on page 221
Configure the MPLS-TE Shared Risk Link Groups: Example, on page 259

Explicit Path

The Explicit Path configuration allows you to configure the explicit path. An IP explicit path is a list of IP
addresses, each representing a node or link in the explicit path.
OL-28381-02
illustrates the MPLS TE SRLG values configured on the bundle interface.
Cisco ASR 9000 Series Aggregation Services Router MPLS Configuration Guide, Release 4.3.x
MPLS Traffic Engineering Shared Risk Link Groups
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