Brocade Network OS Administrator’s Guide v4.1.1 - Manual (Page 669)

e) If the switch is part of a VCS Fabric cluster, verify that the MAC address tables are
synchronized properly across all Brocade VDX switches in the cluster.
f) Check whether LLDP reports neighbors.
g) Check the Ethernet Name Server (ENS) functionality by ensuring that the MAC address
table reports MAC addresses learned from other VCS Fabric switches.
h) Use the l2traceroute command for validating the data-path fabric continuity. This command
helps identify where the packets are being dropped within the fabric.
The command prompts for some basic and allows you to choose to enter some extended
parameters. Currently supported basic parameters include:
• Source Address (SA) and Destination Address (DA) of dynamically learned MAC
addresses
• VLAN
• Edge routing bridge (RBridge) ID
Currently supported extended parameters include:
• Protocol type (IP)
• Source and destination IP addresses
• IP protocol type (recommend TCP)
• Source and destination port numbers
The purpose of IP parameters is to provide a way to make the traceroute packet traverse a
specific ECMP link.
CAUTION
The following step affects configuration and should be used with care.
7. To track certain flows within the fabric, use permit ACLs and monitor the hit increments.
Understanding troubleshooting hotspots
This section provides relevant background information and best practices guidance related to features
of Network OS where problems have been reported. With this guidance, you should be able to avoid
many potential problems.
Licensing
When a licensed feature does not work, one likely cause is that the license has not been installed
correctly. Follow the guidelines and procedures in the Network OS Software Licensing Guide to ensure
your features are licensed properly and those licenses installed correctly.
For license recovery procedures, refer to the Network OS Software Licensing Guide.
STP interoperability with Brocade MLX or other switches
• To use the Spanning Tree Protocol (STP) in a network with Brocade MLX switches, or switches from
other vendors such as Juniper or Cisco, you may have to configure the interface to send BPDUs to
the shared spanning tree MAC address 0100.0ccc.cccd. Without this setting, the RPVST/PVST root
bridge is not recognized on VLANs other than VLAN 1.
Understanding troubleshooting hotspots
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