Cisco Cisco IOS Software Release 12.4(6)T
Interface Input Queue Memory Reclamation
Prerequisites for Interface Input Queue Memory Reclamation
2
Cisco IOS Security Configuration Guide
Prerequisites for
Interface Input Queue Memory Reclamation
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You must be running Cisco IOS Release 12.4(6)T or a later release.
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Additional instructions from a Cisco technical support representative may be required.
Information About
Interface Input Queue Memory
Reclamation
Before modifying the settings for Interface Input Queue Memory Reclamation, you should understand
the following concepts:
the following concepts:
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Interface Wedging and Packet Memory Leaks
In certain situations, errors in the system accounting of incoming packets can occur, leading to a
“memory leak” caused by the input queue. When there is a leak in an interface’s input queue, gradually
the queue reaches its maximum permitted value, causing the interface to become “wedged.” A wedged
interface may stop processing incoming packets altogether. Packet memory leaks can cause interface
input queue wedges.
“memory leak” caused by the input queue. When there is a leak in an interface’s input queue, gradually
the queue reaches its maximum permitted value, causing the interface to become “wedged.” A wedged
interface may stop processing incoming packets altogether. Packet memory leaks can cause interface
input queue wedges.
This enhancement improves the infrastructure for preventing wedged interface input queues, and it
provides a method for changing the defaults of that infrastructure.
provides a method for changing the defaults of that infrastructure.
Note
Additional troubleshooting (debugging) commands were also introduced by this enhancement for use by
technical support representatives in specific situations.
technical support representatives in specific situations.
I/O Memory
The I/O (Input/Output) memory pool is one of the memory types in Cisco IOS software. The input queue
buffers use memory from this pool for processing.
buffers use memory from this pool for processing.
Memory Resource Reclamation for Interfaces
Within the Embedded Resource Manager Infrastructure of Cisco IOS software, a Memory Leak Detector
process (sometimes referred to as the “garbage detection” or “GD” process) works behind the scenes.
As part of the resource reclamation process, packets that the detector finds as leaked can be deallocated
and reused. This feature provides a command (critical rising) that can be used to fine-tune the process
of evoking memory resource reclamation.
process (sometimes referred to as the “garbage detection” or “GD” process) works behind the scenes.
As part of the resource reclamation process, packets that the detector finds as leaked can be deallocated
and reused. This feature provides a command (critical rising) that can be used to fine-tune the process
of evoking memory resource reclamation.