|
Type, Length, Value (TLV) is in the
IS-IS and ES-IS PDUs that contain variable-length fields, depending on the
function of the PDU. Each field contains a type code and length, followed by
the appropriate values. These fields are identified by one octet of type (T),
one octet of length (L) and "L" octets of value (V). The Type field
indicates the type of items in the Value field. The Length field indicates the
length of the Value field. The Value field is the data portion of the packet.
Not all router implementations support all TLVs, but they are required to
ignore and retransmit the ignored types.
|