Reference Guide

OID String OID Name Description
Temperature
.1.3.6.1.4.1.6027.3.10.1.2.5.1.7 chSysPortXfpRecvTemp OID displays the temperature of the
connected optics.
NOTE: These OIDs only generate if
you enable the enable optic-
info-update-interval is
enabled command.
Hardware MIB Buer Statistics
.1.3.6.1.4.1.6027.3.16.1.1.4 fpPacketBuerTable View the modular packet buers details
per stack unit and the mode of allocation.
.1.3.6.1.4.1.6027.3.16.1.1.5 fpStatsPerPortTable View the forwarding plane statistics
containing the packet buer usage per
port per stack unit.
.1.3.6.1.4.1.6027.3.16.1.1.6 fpStatsPerCOSTable View the forwarding plane statistics
containing the packet buer statistics per
COS per port.
Buer Tuning
Buer tuning allows you to modify the way your switch allocates buers from its available memory and helps prevent packet drops
during a temporary burst of trac.
The application-specic integrated circuit (ASICs) implement the key functions of queuing, feature lookups, and forwarding lookups
in hardware.
Forwarding processor (FP) ASICs provide Ethernet MAC functions, queueing, and buering, as well as store feature and forwarding
tables for hardware-based lookup and forwarding decisions. 1G and 10G interfaces use dierent FPs.
You can tune buers at three locations
1. CSF — Output queues going from the CSF.
2. FP Uplink — Output queues going from the FP to the CSF IDP links.
3. Front-End Link — Output queues going from the FP to the front-end PHY.
All ports support eight queues, four for data trac and four for control trac. All eight queues are tunable.
Physical memory is organized into cells of 128 bytes. The cells are organized into two buer pools — the dedicated buer and the
dynamic buer.
• Dedicated buer — this pool is reserved memory that other interfaces cannot use on the same ASIC or by other queues on the
same interface. This buer is always allocated, and no dynamic re-carving takes place based on changes in interface status.
Dedicated buers introduce a trade-o. They provide each interface with a guaranteed minimum buer to prevent an overused
and congested interface from starving all other interfaces. However, this minimum guarantee means that the buer manager
does not reallocate the buer to an adjacent congested interface, which means that in some cases, memory is under-used.
• Dynamic buer — this pool is shared memory that is allocated as needed, up to a congured limit. Using dynamic buers
provides the benet of statistical buer sharing. An interface requests dynamic buers when its dedicated buer pool is
exhausted. The buer manager grants the request based on three conditions:
– The number of used and available dynamic buers.
– The maximum number of cells that an interface can occupy.
– Available packet pointers (2k per interface). Each packet is managed in the buer using a unique packet pointer. Thus, each
interface can manage up to 2k packets.
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Debugging and Diagnostics