3.1. TLV Format

Information in the new Link-State NLRIs and attributes is encoded in Type/Length/Value triplets. The TLV format is shown in Figure 4.

   0                   1                   2                   3
   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |              Type             |             Length            |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  //                        Value (variable)                     //
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                        Figure 4: TLV Format

The Length field defines the length of the value portion in octets (thus, a TLV with no value portion would have a length of zero). The TLV is not padded to 4-octet alignment. Unrecognized types MUST be preserved and propagated. In order to compare NLRIs with unknown TLVs, all TLVs MUST be ordered in ascending order by TLV Type. If there are more TLVs of the same type, then the TLVs MUST be ordered in ascending order of the TLV value within the TLVs with the same type by treating the entire Value field as an opaque hexadecimal string and comparing leftmost octets first, regardless of the length of the string. All TLVs that are not specified as mandatory are considered optional.

3.1. TLV Format​

3.1. TLV Format