White Papers

● Open shortest path first
● Protocol independent multicast — sparse mode
● Intermediate system to intermediate system
Software Resiliency
During normal operations, Dell Networking OS monitors the health of both hardware and software components in the
background to identify potential failures, even before these failures manifest.
System Health Monitoring
Dell Networking OS also monitors the overall health of the system.
Key parameters such as CPU utilization, free memory, and error counters (for example, CRC failures and packet loss) are
measured, and after exceeding a threshold can be used to initiate recovery mechanism.
Failure and Event Logging
Dell Networking systems provide multiple options for logging failures and events.
Trace Log
Developers interlace messages with software code to track the execution of a program.
These messages are called trace messages and are primarily used for debugging and to provide lower-level information then
event messages, which system administrators primarily use. Dell Networking OS retains executed trace messages for hardware
and software and stores them in files (logs) on the internal flash.
● Trace Log — contains trace messages related to software and hardware events, state, and errors. Trace Logs are stored in
internal flash under the directory TRACE_LOG_DIR.
● Crash Log — contains trace messages related to IPC and IRC timeouts and task crashes on line cards and is stored under
the directory CRASH_LOG_DIR.
Core Dumps
A core dump is the contents of RAM a program uses at the time of a software exception and is used to identify the cause of the
exception.
There are two types of core dumps: application and kernel.
● Kernel core dump is the central component of an operating system that manages system processors and memory allocation
and makes these facilities available to applications. A kernel core dump is the contents of the memory in use by the kernel at
the time of an exception.
● Application core dump is the contents of the memory allocated to a failed application at the time of an exception.
System Log
Event messages provide system administrators diagnostics and auditing information.
Dell Networking OS sends event messages to the internal buffer, all terminal lines, the console, and optionally to a syslog server.
For more information about event messages and configurable options, refer to Switch Management.
High Availability (HA)
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