Shared memory log supports filter-based debugging

Junos OS supports filter-based debugging using the shared memory log. Junos OS uses a shared memory space to store log entries for subscriber service daemons, such as jpppd, jdhcpd, jl2tpd, autoconfd, bbe-smgd, authd, cosd, and dfwd. The shared memory log, or shmlog, output can be displayed using the show shmlog entries logname (logname | all) <filter filter> <flag-name flag> command. By default, shared memory logging is enabled. To disable the shmlog, at the [edit system services subscriber-management] hierarchy level, enter the set overrides shmlog disable; configuration statement. By default, shmlog filtering is disabled. To enable shmlog filtering, at the [edit system services subscriber-management overrides] hierarchy level, enter the set shmlog filtering enable; configuration statement. To display shmlog output for all daemon logs, use the logname all option in the show shmlog entries command. To limit shmlog output to a specific daemon log, provide the daemon name after the logname option followed by an asterisk. For example, logname jpppd* or logname authd*. To filter shmlog output, use the filter filter option in the show shmlog entries logname all command. To display a list of valid filters, enter the command show shmlog entries logname all ?. Output can also be limited to shmlog entries with specific flags, such as transmit-packets, configuration, and sessionDb, using the flag-name flag option in the show shmlog entries logname all command. To display a list of valid flags, enter the command show shmlog entries logname all flag-name ?. To direct shmlog output to a file, at the [edit system services subscriber-management overrides] hierarchy level, enter the set shmlog file <filename>; configuration statement. To view shmlog output stored in a text file, use the command show shmlog entries filename filename.