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DHCP Option 82 Audit Messages

Menu path: Auditing > DHCP Option 82 Audit Messages.

DHCP Option 82 allows a DHCP Relay Agent to insert circuit specific information into a request that is being forwarded to a DHCP server. Specifically the option works by setting two sub-options: Circuit ID and Remote ID.

DHCP Option 82 settings are described in RFC 3046.

The view offers selectable columns (with the symbol); the initial default columns are:

• MAC Address
• Circuit ID String
• Host
• Module
• Option82 Switch
• Port
• Device ID
• DHCP Option 82 VLAN
• Created At

Log entries can be searched with a Simple Search or Advanced Search, based on the position of the slider. Simple searches consist of a search for MAC address, whereas advanced searches use multiple search conditions.

The simple search choice offers a straightforward means of searching user entries:

• Type any text into the Search by MAC address box and press the button. Any entry whose MAC Address contains the text will be displayed in the list.
• The search box and the listing are reset back to the complete list via the button.
• Export to CSV - the results of the current search are saved to a file named clients.csv. Previous output is not overwritten; new versions are labeled clients(1).csv, clients(2).csv, etc.

Select the slider to access the advanced searches page. Multiple or conditions are joined together with and conjunctions. Each element of an or set can be deleted with the symbol or reordered by selecting the item's symbol. Reordering can occur across or sets.

Several facilities exist for saving and using saved searches:

• In the drop-down:
  • Use the Save Search choice to name and save the current search conditions.
  • Previously saved searches are available in the list as well.
  • Saved searches will be listed along the left-hand edge of the screen.
  • The search terms can also be exported or imported in JSON format.
• - the results of the current search are saved to a file named clients.csv. Previous output is not overwritten; new versions are labeled clients(1).csv, clients(2).csv, etc.

Each condition is in three parts:

• Log entry property - one of the characteristics of the log entry. Choose from the full list of elements in the drop-down list.
• Compare operation - one of:
  • is - matches the comparison string
  • is not - does not match the comparison string
  • starts with - starts with the comparison string
  • ends with - ends with the comparison string
  • matches - the user element is matched against a regular expression (regexp). Regexp is a powerful language for expressing string matches. An introduction to regexps is found here. A simple search is the equivalent of using the matches operation with the equivalent text.

• Comparison string or choice - the string or choice to match against or use as a regular expression.