Cisco ASR 920 series Quick guide

MPLS Traffic Engineering Path Calculation and Setup Configuration
Guide, Cisco IOS XE Release 3S (Cisco ASR 920 Series)
First Published: 2014-07-29
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CONTENTS
CHAPTER 1 MPLS Traffic Engineering –Bundled Interface Support 1
Finding Feature Information 1
Prerequisites for MPLS TE –Bundled Interface Support 2
Restrictions for MPLS TE –Bundled Interface Support 2
Information About MPLS TE –Bundled Interface Support 2
Cisco EtherChannel Overview 2
Cisco Gigabit EtherChannel Overview 3
Load Balancing and Min-Links in EtherChannel 3
How to Configure MPLS TE –Bundled Interface Support 4
Configuring MPLS TE on an EtherChannel Interface 4
Configuration Examples for MPLS TE Bundled Interface Support 5
Example: Configuring MPLS TE on an EtherChannel Interface 5
Example: Configuring MPLS TE - Bundled Interface Support over Gigabit Etherchannel 6
Additional References for MPLS TE - Bundled Interface Support 8
Feature Information for MPLS Traffic Engineering—Bundled Interface Support 8
Glossary 9
CHAPTER 2 MPLS Point-to-Multipoint Traffic Engineering 11
Information About MPLS Point-to-Multipoint Traffic Engineering 11
MPLS Point-to-Multipoint Traffic Engineering Overview 11
How P2MP TE Sub-LSPs Are Signaled 13
How P2MP TE Traffic Is Forwarded 14
Computing the IGP Path Using Dynamic Paths or Explicit Paths 16
Remerge Events 16
Crossover Events 16
Benefits of MPLS Point-to-Multipoint Traffic Engineering 16
MPLS Point-to-Multipoint Traffic Engineering—Re-optimizing Traffic 17
P2P TE Tunnels Coexist with P2MP TE Tunnels 17
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Using FRR to Protect P2MP TE Links 18
FRR Failure Detection Mechanisms 20
Bandwidth Preemption for P2MP TE 20
How to Configure MPLS Point-to-Multipoint Traffic Engineering 21
Configuring the Headend Routers 21
Configuring the Midpoint Routers 24
Configuring the Tailend Routers 25
Configuring FRR with P2MP TE Tunnels 27
Enabling MPLS Traffic Engineering System Logging of Events 27
Verifying the Configuration of MPLS Point-to-Multipoint Traffic Engineering 28
Verifying the Configuration of the Headend Router 28
Verifying the Configuration of the Midpoint Routers 30
Verifying the Configuration of the Tailend Routers 31
Configuration Examples for MPLS Point-to-Multipoint Traffic Engineering 33
Example Configuration of the Headend Router (PE5) 33
Example Configuration of the Midpoint Router (P1) 36
Example Configuration of the Tailend Router (PE1) 37
Additional References 38
Feature Information for MPLS Point-to-Multipoint Traffic Engineering 39
Glossary 40
CHAPTER 3 MPLS Traffic Engineering over Bridge Domain Interfaces 43
Prerequisites for Configuring MPLS TE over BDI 43
Restrictions for MPLS TE over BDI 44
Information About MPLS Traffic Engineering over BDI 44
Features of MPLS Traffic Engineering over BDI 44
Supported Features 44
How to Configure MPLS Traffic Engineering over BDI 44
Configuring MPLS TE over BDI 45
Configuring the RSVP Bandwidth 46
Verifying That MPLS TE over BDI Is Operational 47
Troubleshooting Tips 47
Configuration Example for MPLS Traffic Engineering over BDI 48
Configuring Interface Tunnel Example 48
Configuring RSVP Bandwidth Example 48
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Contents

CHAPTER 1
MPLS Traffic Engineering –Bundled Interface
Support
The MPLS Traffic Engineering - Bundled Interface Support feature enables Multiprotocol Label Switching
(MPLS) traffic engineering (TE) tunnels over the bundled interfaces—EtherChannel and Gigabit EtherChannel
(GEC).
The Resource Reservation Protocol (RSVP) notifies TE about bandwidth changes that occur when member
links are added or deleted, or when links become active or inactive. TE notifies other nodes in the network
via Interior Gateway Protocol (IGP) flooding. By default, the bandwidth available to TE Label-Switched
Paths (LSPs) is 75 percent of the interface bandwidth. You can change the percentage of the global bandwidth
available for TE LSPs by using an RSVP command on the bundled interface. Bandwidth reservation and
preemption are supported.
The Fast Reroute (FRR) feature is supported on bundled interfaces. FRR is activated when a bundled interface
goes down; for example, if you enter the shutdown command to shut down the interface or fewer than the
required minimum number of links are operational.
•Finding Feature Information, page 1
•Prerequisites for MPLS TE –Bundled Interface Support, page 2
•Restrictions for MPLS TE –Bundled Interface Support, page 2
•Information About MPLS TE –Bundled Interface Support, page 2
•How to Configure MPLS TE –Bundled Interface Support, page 4
•Configuration Examples for MPLS TE Bundled Interface Support, page 5
•Additional References for MPLS TE - Bundled Interface Support, page 8
•Feature Information for MPLS Traffic Engineering—Bundled Interface Support, page 8
•Glossary, page 9
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and
feature information, see Bug Search Tool and the release notes for your platform and software release. To
MPLS Traffic Engineering Path Calculation and Setup Configuration Guide, Cisco IOS XE Release 3S (Cisco ASR
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find information about the features documented in this module, and to see a list of the releases in which each
feature is supported, see the feature information table.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support.
To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Prerequisites for MPLS TE –Bundled Interface Support
•Configure Multiprotocol Label Switching (MPLS) traffic engineering (TE) tunnels.
•Enable Cisco Express Forwarding in global configuration mode.
•Enable Resource Reservation Protocol (RSVP) feature.
•Configure EtherChannel.
•Configure Gigabit EtherChannel.
Restrictions for MPLS TE –Bundled Interface Support
•Traffic engineering over switch virtual interfaces (SVIs) is not supported unless the SVI consists of a
bundle of links that represent a single point-to-point interface.
•There must be a valid IP address configuration on the bundled interface and there must not be an IP
address configuration on the member links.
Information About MPLS TE –Bundled Interface Support
Cisco EtherChannel Overview
Cisco EtherChannel technology builds upon standards-based 802.3 full-duplex Fast Ethernet to provide
network managers with a reliable, high-speed solution for the campus network backbone. EtherChannel
technology provides bandwidth scalability within the campus by providing up to 800 Mbps, 8 Gbps, or 80
Gbps of aggregate bandwidth for a Fast EtherChannel, Gigabit EtherChannel, or 10 Gigabit EtherChannel
connection, respectively. Each of these connection speeds can vary in amounts equal to the speed of the links
used (100 Mbps, 1 Gbps, or 10 Gbps). Even in the most bandwidth-demanding situations, EtherChannel
technology helps to aggregate traffic, keeps oversubscription to a minimum, and provides effective
link-resiliency mechanisms.
Cisco EtherChannel Benefits
Cisco EtherChannel technology allows network managers to provide higher bandwidth among servers, routers,
and switches than a single-link Ethernet technology can provide.
Cisco EtherChannel technology provides incremental scalable bandwidth and the following benefits:
•Standards-based—Cisco EtherChannel technology builds upon IEEE 802.3-compliant Ethernet by
grouping multiple, full-duplex point-to-point links. EtherChannel technology uses IEEE 802.3 mechanisms
for full-duplex autonegotiation and autosensing, when applicable.
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Prerequisites for MPLS TE –Bundled Interface Support

•Flexible incremental bandwidth—Cisco EtherChannel technology provides bandwidth aggregation in
multiples of 100 Mbps, 1 Gbps, or 10 Gbps, depending on the speed of the aggregated links. For example,
network managers can deploy EtherChannel technology that consists of pairs of full-duplex Fast Ethernet
links to provide more than 400 Mbps between the wiring closet and the data center. In the data center,
bandwidths of up to 800 Mbps can be provided between servers and the network backbone to provide
large amounts of scalable incremental bandwidth.
•Load balancing—Cisco EtherChannel technology comprises several Fast Ethernet links and is capable
of load balancing traffic across those links. Unicast, broadcast, and multicast traffic is evenly distributed
across the links, providing improved performance and redundant parallel paths. When a link fails, traffic
is redirected to the remaining links within the channel without user intervention and with minimal packet
loss.
•Resiliency and fast convergence—When a link fails, Cisco EtherChannel technology provides automatic
recovery by redistributing the load across the remaining links. When a link fails, Cisco EtherChannel
technology redirects traffic from the failed link to the remaining links in less than one second. This
convergence is transparent to the end user—no host protocol timers expire and no sessions are dropped.
Cisco Gigabit EtherChannel Overview
Cisco Gigabit EtherChannel (GEC) is a high-performance Ethernet technology that provides transmission
rates in Gigabit per second (Gbps). A Gigabit EtherChannel bundles individual ethernet links (Gigabit Ethernet
and 10 Gigabit Ethernet) into a single logical link that provides the aggregate bandwidth up to four physical
links. All LAN ports in each EtherChannel must be of the same speed and must be configured as either Layer
2 or Layer 3 LAN ports. Inbound broadcast and multicast packets on one link in an EtherChannel are blocked
from returning on any other link in the EtherChannel.
Load Balancing and Min-Links in EtherChannel
Load balancing affects the actual and practical bandwidth that can be used for TE. Multilink load balancing
uses a per-packet load balancing method. All of the bundle interface bandwidth is available. EtherChannel
load balancing has various load balancing methods, depending on the traffic pattern and the load balancing
configuration. The total bandwidth available for TE may be limited to the bandwidth of a single member link.
On EtherChannel, min-links is supported only in the Link Aggregation Control Protocol (LACP). For other
EtherChannel protocols, the minimum is one link, by default, and it is not configurable. To configure min-links
for EtherChannel, use the port-channel min-links command.
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MPLS Traffic Engineering –Bundled Interface Support
Cisco Gigabit EtherChannel Overview

How to Configure MPLS TE –Bundled Interface Support
Configuring MPLS TE on an EtherChannel Interface
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number [name-tag]
4. ip address ip-address mask [secondary]
5. mpls traffic-eng tunnels
6. mpls traffic-eng backup-path tunnel
7. port-channel min-links min-num
8. ip rsvp bandwidth [interface-kbps] [single-flow-kbps]
9. end
DETAILED STEPS
PurposeCommand or Action
Enables privileged EXEC mode.enable
Step 1
Example:
Device> enable
•Enter your password if prompted.
Enters global configuration mode.configure terminal
Example:
Device# configure terminal
Step 2
Creates an EtherChannel bundle, assigns a group number to
the bundle, and enters interface configuration mode.
interface type number [name-tag]
Example:
Device(config)# interface port-channel 1
Step 3
Specifies an IP address for the EtherChannel group.
ip address ip-address mask [secondary]
Example:
Device(config-if)# ip address 10.0.0.4
255.255.255.0
Step 4
Enables MPLS TE tunnel signaling on an interface.mpls traffic-eng tunnels
Step 5
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How to Configure MPLS TE –Bundled Interface Support

PurposeCommand or Action
Example:
Device(config-if)# mpls traffic-eng tunnels
•MPLS TE tunnel should be enabled on the device before
enabling the signaling.
(Optional) Configures the physical interface to use a backup
tunnel in the event of a detected failure on that interface.
mpls traffic-eng backup-path tunnel
Example:
Device(config-if)# mpls traffic-eng
backup-path Tunnel120
Step 6
Specifies that a minimum number of bundled ports in an
EtherChannel is required before the channel can be active.
port-channel min-links min-num
Example:
Device(config-if)# port-channel min-links 2
Step 7
Enables RSVP for IP on an interface and specifies a percentage
of the total interface bandwidth as available in the RSVP
bandwidth pool.
ip rsvp bandwidth [interface-kbps] [single-flow-kbps]
Example:
Device(config-if)# ip rsvp bandwidth 100
Step 8
Exits interface configuration mode and returns to privileged
EXEC mode.
end
Example:
Device(config-if)# end
Step 9
ConfigurationExamplesfor MPLSTEBundled InterfaceSupport
Example: Configuring MPLS TE on an EtherChannel Interface
Device> enable
Device# configure terminal
Device(config)# interface port-channel 1
Device(config-if)# ip address 10.0.0.4 255.255.255.0
Device(config-if)# mpls traffic-eng tunnels
Device(config-if)# mpls traffic-eng backup-path Tunnel 120
Device(config-if)# port-channel min-links 2
Device(config-if)# ip rsvp bandwidth 100
Device(config-if)# end
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Configuration Examples for MPLS TE Bundled Interface Support

Example: Configuring MPLS TE - Bundled Interface Support over Gigabit
Etherchannel
The following example shows how to enable MPLS TE –bundled interface support over GEC on Cisco
devices:
Device> enable
Device# configure terminal
! Enable global MPLS TE on routers
Device(config)# router ospf 100
Device(config-router)# network 10.0.0.1 0.0.0.255 area 0
Device(config-router)# mpls traffic-eng area 0
Device(config-router)# mpls traffic-eng router-id Loopback 0
Device(config-router)# exit
! Configure GEC interface and enable MPLS TE and RSVP on interface
Device(config)# interface Port-channel 1
Device(config-if)# ip address 10.0.0.1 255.255.255.0
Device(config-if)# mpls traffic-eng tunnels
Device(config-if)# ip rsvp bandwidth
Device(config-if)# exit
! Define explicit path
Device(config)# ip explicit-path name primary enable
Device(cfg-ip-expl-path)# next-address 172.12.1.2
Device(cfg-ip-expl-path)# next-address 172.23.1.2
Device(cfg-ip-expl-path)# next-address 172.34.1.2
Device(cfg-ip-expl-path)# next-address 10.4.4.4
Device(cfg-ip-expl-path)# exit
! Configure primary tunnel on head-end device
Device(config)# interface Tunnel 14
Device(config-if)# ip unnumbered Loopback 0
Device(config-if)# tunnel mode mpls traffic-eng
Device(config-if)# tunnel destination 10.10.10.0
Device(config-if)# tunnel mpls traffic-eng autoroute announce
Device(config-if)# tunnel mpls traffic-eng path-option 10 explicit name primary
Device(config-if)# tunnel mpls traffic-eng fast-reroute
Device(config-if)# exit
! Configure backup tunnel on head-end or mid-point device
Device(config)# interface Tunnel 23
Device(config-if)# ip unnumbered Looback 0
Device(config-if)# tunnel mode mpls traffic-eng
Device(config-if)# tunnel destination 10.20.10.0
Device(config-if)# tunnel mpls traffic-eng path-option 10 explicit name backup
Device(config-if)# exit
! Configure backup tunnel on protected GEC interface
Device(config)# interface Port-channel 1
Device(config-if)# ip address 10.0.0.1 255.255.255.0
Device(config-if)# mpls traffic-eng tunnels
Device(config-if)# mpls traffic-eng backup-path Tunnel 23
Device(config-if)# ip rsvp bandwidth percent 20
Device(config-if)# lacp min-bundle 2
Device(config-if)# exit
! Configure GEC interface
Device(config)# interface GigabitEthernet 0/0/1
Device(config-if)# no ip address
Device(config-if)# channel-group 1 mode active
Device(config-if)# exit
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Example: Configuring MPLS TE - Bundled Interface Support over Gigabit Etherchannel