Brocade MLX Series and Brocade NetIron XMR Diagnostic Guide ...

2TCAM partitioning and usageDec 10 17:21:39 L2 Trace: trace_l2_receive_reply(): Exit 4: Processed HopDec 10 17:21:39 L2 Trace: trace_l2_timer(): EnteringDec 10 17:21:39 L2 Trace: trace_l2_timer(): Exit 3 (Stage 2)Dec 10 17:21:40 L2 Trace: trace_l2_timer(): EnteringDec 10 17:21:40 L2 Trace: trace_l2_timer(): Have no addressVlan 3 L2 topology probed, use "trace-l2 show" to displayDec 10 17:21:40 L2 Trace: trace_l2_timer(): Exit 4: End of functionCommon diagnostic scenariosSystem issues are rare. However, some problem sources can include:• Software versions are not compatible.• Line modules or switch fabric modules are not functioning properly.• Environmental conditions, such as temperatures that are above or below operating thresholds,are affecting operation of hardware components.If you are experiencing system issues, contact Brocade Technical Support for help introubleshooting your system.TCAM partitioning and usageTernary Content Addressable Memory (TCAM) is a component of Brocade devices that facilitateshardware-forwarding. As packets flow through the Brocade device from a given source to a givendestination, the management processor records forwarding information about the flow in TCAMentries. A TCAM entry generally contains next-hop information, such as the outgoing port, the MACaddress of the next-hop router, a VLAN tag, and so on. Once the Brocade device has thisinformation in TCAM, packets with the same source and destination can be forwarded by hardware,bypassing the management processor, and speeding up forwarding time.TCAM entries can contain Layer 2, Layer 3, or Layer 4 information. Each type of TCAM entry has itsown format:• Layer 2 TCAM entries contain destination MAC information and deal with 802.1p (priority) andVLAN information.• Layer 3 TCAM entries contain destination IP information.• Layer 4 TCAM entries contain destination IP, destination TCP/UDP port, source IP, and sourceTCP/UDP port information.When a Brocade device is initialized, the software partitions the available TCAM into segments forLayer 2, Layer 3, or Layer 4 information. The percentage of TCAM devoted to each type of TCAMentry is determined by the profile.12 Brocade MLX Series and Brocade NetIron XMR Diagnostic Guide53-1002426-02