Install guide

60 Classifying According to the Layer 5 Byte Release Note
Software Version 2.7.5
C613-10454-00 REV A
[L5BYTE07=byteoffset,bytevalue[,bytemask]]
[L5BYTE08=byteoffset,bytevalue[,bytemask]]
[L5BYTE09=byteoffset,bytevalue[,bytemask]]
[L5BYTE10=byteoffset,bytevalue[,bytemask]]
[L5BYTE11=byteoffset,bytevalue[,bytemask]]
[L5BYTE12=byteoffset,bytevalue[,bytemask]]
[L5BYTE13=byteoffset,bytevalue[,bytemask]]
[L5BYTE14=byteoffset,bytevalue[,bytemask]]
[L5BYTE15=byteoffset,bytevalue[,bytemask]]
[L5BYTE16=byteoffset,bytevalue[,bytemask]]
Description The new l5byte01 to l5byte16 parameters each specify the properties of a
single byte field to match in the Layer 5 part of IP packets, which is the TCP or
UDP payload. For each byte field you want to match, specify:
■ byteoffset, which is a decimal number in the range 0 to 37. This specifies the
location of the byte to match. It refers to the offset from the start of Layer 5,
after the UDP or TCP header.
■ bytevalue, which is a 2-digit hexadecimal number. This specifies the value
of the byte at the position in the frame that is determined by byteoffset. The
classifier matches packets that have this value at this location
■ (optionally) bytemask, which is a 2-digit hexadecimal number. This specifies
an eight-bit binary mask to apply to the field. When a bit is set to 1 in the
mask, the value of the bit at the same position in the byte value is used to
determine a match. A 0 in the mask means that the corresponding bit is
ignored. The default is ff, which means the classifier matches against all
bits in the byte.
Caution The classifier matches only Layer 5 bytes that are within the first 80
bytes of the IP packet. The classifier does not match against bytes that are later
in the packet, even if they match the classifier’s settings.
When you consider packet length, remember that the location of Layer 5 in a
frame varies depending on the length of the lower-layer headers. This is because
header values such as the VLAN tag can be missing, and header values such as
the Ethernet format specification vary in length.
You must use l5byte01 as the first byte field and you must number additional
byte fields sequentially. Each field must have a greater offset than the fields
that precede it.
The l5byte parameters match frames with a valid TCP or UDP header, when
the network protocol is IP version 4. Therefore, protocol defaults to ip and does
not need to be specified. You also do not have to specify ipprotocol, but by
default the classifier applies to both TCP and UDP packets.