Cisco CRS-1 - Carrier Routing System Router Troubleshooting Guide

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Cisco IOS XR Troubleshooting Guide for the Cisco CRS-1 Router
OL-21483-02
Chapter 13 Troubleshooting Load Balancing
Troubleshooting Layer 2 Load Balancing
Note Unlike configuration procedures, troubleshooting is not a deterministic process. This section provides a
typical procedure for troubleshooting load balancing within an Ethernet bundle. For a example of this
procedure, see Troubleshooting Layer 2 Load Balancing Example, page 13-246.
SUMMARY STEPS
1. show bundle {Bundle-Ether | Bundle-POS} interface-path-id
2. show route destination-address
3. show cef ipv4 prefix
DETAILED STEPS
Configuring Layer 4 Load Balancing
Layer 2 load balancing is achieved by inspecting the Layer 3 and Layer 4 information in the encapsulated
packet. By default, the load balancing algorithm uses Layer 3 information only. This section describes
how to configure load balancing to use both Layer 3 and Layer 4 information. If your system only uses
Layer 3 load balancing, retain the default load balancing setting.
For the configuration procedure, see Configuring Layer 4 Load Balancing, page 13-236.
Viewing the Expected Paths and Measuring the Flows
Cisco IOS XR provides a bundle utility that predicts how Layer 2 loads are balanced across member
links. This is an interactive tool prompts for the information that the load balancing algorithm uses to
allocate flows to member links.
Command or Action Purpose
Step 1
show bundle {Bundle-Ether | Bundle-POS}
interface-path-id
Example:
RP/0/RP0/CPU0:Router# show bundle
bundle-ether 12
Displays the bundle status.
Verify that the bundle has the expected number of links. If
not, troubleshoot the bundle first.
Step 2
show route destination-address
Example:
RP/0/RP0/CPU0:Router# show route 10.1.2.1
Displays the routes to a destination address. Use a
destination address on another host that is reachable
through the bundle.
Verify that the route to the desalination address includes the
bundle interface. If not, make sure that the bundle interface
is included in the IGP process configuration.
Step 3
show cef ipv4 prefix
Example:
RP/0/RP0/CPU0:router# show cef ipv4 10.1.2.1
Displays the CEF forwarding table. Verify that it contains
the same bundle interface that the routing table has for this
subnet prefix.

Cisco CRS-1 - Carrier Routing System Router Specifications

General

Brand	Cisco
Model	CRS-1 - Carrier Routing System Router
Category	Network Router
Language	English