A User Defined Field (UDF) can match up to 128 bytes of a packet starting from the first byte of the packet. The relative offset can be given to the match location. The length of the match can be from 1 to 4 bytes. Hardware with a Trident chip supports the creation of 8 UDF IDs. Each ID can match a 2 byte portion of a packet. Creating a UDF with a length of 3 or 4 bytes requires 2 UDF IDs whereas a UDF with a length of 1 or 2 bytes requires 1 UDF ID. The length specified for each UDF determines the total number of UDFs supported by Netvisor. If you specify a length of 3 or 4 bytes, a maximum of 4 UDFs can be created. If you specify a length of 1 or 2 bytes, a maximum of 8 UDFs can be created.

Syntax   udf-create name

name name-string

Create the UDF name

scope local|fabric

Scope for the UDF

offset number-bytes

The offset in bytes. This is a value between 1, and 128.

length number-bytes

The length in bytes. This is a value between 1, and 4 bytes.

header packet-start|l3-outer|l3-inner|l4-outer|l4-inner

The header used to calculate the offset.

Defaults   None

Access   CLI


Version 2.5.3

Command introduced.

Usage   Use this command to create customized fields for vFlow configurations.

Examples  To create a UDF with scope local, offset 10, length 2, and header packet-start, use the following syntax:

CLI (network-admin@switch) > udf-create name u1 scope local offset 10 length 2 header packet-start