Troubleshooting Lre Port Configuration - Cisco WS-C2955T-12 Software Manual

Chapter 9 Troubleshooting

Troubleshooting LRE Port Configuration

Table 9-6
Ethernet (LRE) ports on the Catalyst 2900 LRE XL switches. For additional information about what can
affect LRE connections, see the
LRE command descriptions provide additional troubleshooting information. Refer to the switch
command reference.
Table 9-6 LRE Port Problems
Problem Suspected Cause and Suggested Solution
Amber LRE port LED The switch and CPE are unable to establish an LRE link using the selected profile.
Excessive CRC errors
on an LRE link
High Reed-Solomon
error count without
CRC errors
78-6511-08
lists problems you might encounter when configuring and monitoring the Long-Reach
Change to a profile with a lower data rate (for example, use LRE-5 instead of LRE-15).
•
Reduce the effect of stubs or bridge taps by terminating them with 300-ohm microfilters.
•
A noisy environment (such as motors and power surges) is causing interference with the LRE
•
link.
Change to a profile that has the interleaver feature enabled, such as the LRE-5, LRE-10,
–
LRE-15, LRE-10-1, LRE-10-3, or LRE-10-5 profile.
Change to a profile with a lower data rate (for example, use LRE-5 instead of LRE-15) to
–
increase the noise margin.
The LRE link length and quality are close to the limit of operation.
•
Change to a lower profile (for example, LRE-5 instead of LRE-15).
–
Reduce the effect of stubs or bridge taps by terminating them with 300-ohm microfilters.
–
Interleaver is helping Reed-Solomon error correction to function correctly in a noisy
•
environment. This situation means that the system is on the verge of generating CRC errors.
Change to a profile that has the interleaver feature enabled, such as the LRE-5, LRE-10,
–
LRE-15, LRE-10-1, LRE-10-3, or LRE-10-5 profile.
Change to a profile with a lower data rate (for example, use LRE-5 instead of LRE-15) to
–
increase the noise margin.
The LRE link length and quality are close to the limit of operation.
•
Change to a profile with a lower data rate (for example, use LRE-5 instead of LRE-15).
–
Reduce the effect of stubs or bridge taps by terminating them with 300-ohm microfilters.
–
Catalyst 2900 Series XL and Catalyst 3500 Series XL Software Configuration Guide
"Environmental Considerations for LRE Links" section on page
Troubleshooting LRE Port Configuration
7-18.
9-9