When you write the content for each IPS signature, you must use the following syntax:
rule protocol-type, [protocol-options,] [ip-protocol options,] msg, content...
ICMP protocol arguments
Refer to RFCs 792 and 1256 for detailed descriptions of valid ICMP protocol type and code combinations.
Table: ICMP protocol arguments
Attribute
Description
Syntax
type
ICMP protocol type
type operator value
where value is an unsigned 8-bit number from 0 to 255.
For example:type=0
code
ICMP protocol type
code operator value
where value is an unsigned 8-bit number from 0 to 255.
For example:
code<=10