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
DETAILED STEPS
Troubleshooting Layer 2 Load Balancing
This section describes how to troubleshoot load balancing at Layer 2. This procedure is specific to
Layer 2 bundles.
• Verifying the Bundle Status, IGP Route, and CEF Database
• Configuring Layer 4 Load Balancing
• Viewing the Expected Paths and Measuring the Flows
Verifying the Bundle Status, IGP Route, and CEF Database
Cisco Express Forwarding uses the path information in the IP routing table to balance traffic over
multiple links. For this reason, confirming proper Cisco Express Forwarding load balancing begins with
confirming the contents of the IP routing table. When troubleshooting a bundle, verify that the bundle
us up and that the IGP route to the desired destination includes the bundle interface.
Command or Action Purpose
Step 1
show cef ipv4 [ prefix [ mask ]] | interface-type
interface-path-id ] [detail] [location node-id ]
Example:
RP/0/RP0/CPU0:router# show cef ipv4 10.1.2.1
detail
Displays the CEF forwarding table. Verify that it contains
the same interfaces that the routing table has for this
destination.
Step 2
RP/0/RP0/CPU0:Router# show cef [ipv4 | ipv6]
exact-route
source-address destination address
[protocol
type ] [source-port source-port ]
[destination-port
destination-port ]
[ingress-interface type
interface-path-id ]
[ policy-class value ] [ detail | location
node-id
]
Example:
RP/0/RP0/CPU0:router# show cef exact-route
192.168.254.1 10.1.2.1 protocol tcp source-port
5500 destination-port 80 ingress-interface
gi0/6/5/4
Displays the exact route that a specific flow would take. Use
this command for several flows to verify that they are
distributed equally over the parallel interfaces.
Step 3
show interfaces [ type interface-path-id | all |
local | location
node-id ] [accounting | brief |
detail | summary]
Example:
RP/0/RP0/CPU0:router# show interfaces
accounting rates
Displays the traffic rates by interface. Use this command to
verify that the simulated traffic takes the expected egress
interface.

Cisco CRS-1 - Carrier Routing System Router Specifications

General

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