Finisar Surveyor - Manual (Page 144)

7-8
Surveyor
User’s Guide
Multiple Byte Patterns in Filter Templates
Filter templates can be “several templates in one.” For example, HTTP, TELNET,
and SNMP are provided as single filter templates, but they consist of both source
and destination ports. In other words, the template itself contains an OR condition,
and will capture a packet whether it appears in the offset for the source port or the
offset for the destination port.
An example
Template Description window is shown below. The HTTP port as the
source or destination will be selected by the filter template. Two byte patterns are
defined:
First Pattern Second Pattern
Offset Pattern Offest Pattern
12 0800 12 0800
23 06 23 06
34 0050 36 0050
Figure 7-2. Template Description Window Showing a Macro Filter
Creating Custom Filter Templates
Custom filter templates are created from the Filter Design window. Custom filter
templates display under Custom_Templates in the Available Filter Templates
box of this window. Custom templates allow precise control over the information
captured or displayed.
Custom templates are created by modifying a pre-defined template or by directly
entering values in the correct offsets in the Current Filter Template Display area.
Custom Templates Based on Pre-Defined Templates
Custom filter templates can be created by selecting a pre-defined template and add-
ing conversations or port numbers. For example, assume you want to filter HTTP
packets going to or coming from a station. You could select the HTTP filter template
and enter the station you want to filter on in the Add Conversation to Template area.