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interface-traceoptions (DHCP)



Hierarchy Level

Release Information

Statement introduced in Junos OS Release 11.4.

Statement introduced in Junos OS Release 12.3R2 for EX Series switches.


Configure extended DHCP tracing operations that can be enabled on a specific interface or group of interfaces.

Replaces deprecated interface-traceoptions statements at the [edit forwarding-options dhcp-relay] and [edit system services dhcp-local-server] hierarchy levels.

To enable the tracing operation on the specific interfaces, you use the interface interface-name trace statement.


file filename—Name of the file to receive the output of the tracing operation. Enclose the name within quotation marks. All files are placed in the directory /var/log.

files number—(Optional) Maximum number of trace files to create before overwriting the oldest one. If you specify a maximum number of files, you also must specify a maximum file size with the size option.

Range: 2 through 1000

Default: 3 files

flag flag—Tracing operation to perform. To specify more than one tracing operation, include multiple flag statements

  • all—Trace all events

  • packet—Trace packet and option decoding operations

  • state—Trace changes in state

level—Level of tracing to perform; also known as severity level. The option you configure enables tracing of events at that level and all higher (more restrictive) levels. You can specify any of the following levels:

  • all—Match messages of all levels.

  • error—Match error messages.

  • info—Match informational messages.

  • notice—Match notice messages about conditions requiring special handling.

  • verbose—Match verbose messages. This is the lowest (least restrictive) severity level; when you configure verbose, messages at all higher levels are traced. Therefore, the result is the same as when you configure all.

  • warning—Match warning messages.

Default: error

match regular-expression—(Optional) Refine the output to include lines that contain the regular expression.

no-remote-trace—Disable remote tracing.

no-world-readable—(Optional) Disable unrestricted file access.

size maximum-file-size—(Optional) Maximum size of each trace file. By default, the number entered is treated as bytes. Alternatively, you can include a suffix to the number to indicate kilobytes (KB), megabytes (MB), or gigabytes (GB). If you specify a maximum file size, you also must specify a maximum number of trace files with the files option.

Syntax: sizek to specify KB, sizem to specify MB, or sizeg to specify GB

Range: 10240 through 1073741824

world-readable—(Optional) Enable unrestricted file access.

Required Privilege Level

trace—To view this statement in the configuration.

trace-control—To add this statement to the configuration.