Troubleshooting guide

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ATM and Layer 3 Switch Router Troubleshooting Guide
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Chapter 11 Troubleshooting Layer 3 Network Connections
Troubleshooting SDM Problems
Troubleshooting SDM Problems
This section describes the switching database manager (SDM) features built into your switch router. This
chapter includes the following topics:
• SDM Overview, page 11-56
• Troubleshooting SDM Problem Commands, page 11-57
The information in this section applies to the Catalyst 8540 CSR and Catalyst 8540 MSR with Layer 3
functionality.
For detailed SDM configuration information, refer to the “Configuring Switching Database Manager”
chapter in the Layer 3 Switching Software Feature and Configuration Guide.
SDM Overview
SDM partitions TCAM space into multiple regions. Each region is protocol specific. SDM interacts with
the individual protocol control layer to store Layer 3 switching information. SDM consists of the
following types of regions:
• Exact-match region—The exact-match region consists of Layer 3 entries for multiple protocol
regions such as IP adjacencies and IPX node.
• Longest-match region—Each longest-match region consists of multiple “buckets” or groups of
Layer 3 address entries organized in decreasing order by mask length. All entries within a bucket
share the same mask value and key size. The buckets can change their size dynamically by
borrowing address entries from neighboring buckets. Although the size of the whole protocol region
is fixed, you can reconfigure it. The reconfigured size of the protocol region is effective only at the
next system reboot.
• First-match region—The first-match region consists of ACL entries; lookup stops at first match of
the entry.
The enhanced Gigabit Ethernet interface module supports TCAM sizes of 32 KB, 64 KB, or 256 KB.
Each entry in TCAM is 32 bits wide. Since SDM is responsible for managing TCAM space, SDM
partitions the entire TCAM space for each protocol region based on user configuration. A change in the
partition configuration takes effect only during the next system reboot.
Table 11-2 lists default partitioning for each protocol region in TCAM.
Table 11-2 TCAM Protocol Region Default Partitioning
Protocol Region Lookup Type Key Size Default Size No. of TCAM Entries
ipx-bvi-network Exact-match 32 bits 32 32
ip-adjacency Exact-match 32 bits 2048 2048
ipx-node Exact-match 64 bits 2048 4096
ip-prefix Longest-match 32 bits 8192 8192
ipx-network Exact-match 32 bits 6144 6144
ip-mcast Longest-match 64 bits 3072 6144
l2-switching Exact-match 64 bits 1024 2048
udp-flooding Exact-match 64 bits 256 512
access-list First-match 128 bits 512 8192