Hi FRR team, File: https://github.com/FRRouting/frr/blob/master/isisd/isis_tlvs.c In unpack_item_ext_subtlvs() there are few sub-tlvs whose unpacking need to be fixed. Basically 2 fixes are required: 1. Default length of sub-tlvs are not correct 2. If length is not as per standard, then pointer has to be advanced to the length value. In below example, these 2 fixes are tagged as FIXME#1 and FIXME#2 For example: unpack_item_ext_subtlvs() { . . . . . . case ISIS_SUBTLV_MM_DELAY: if (subtlv_len != ISIS_SUBTLV_DEF_SIZE) { // FIXME#1: As per standard this is 8 byte sbuf_push(log, indent, "TLV size does not match expected size for Min/Max Link Delay!\n"); // FIXME#2: Advance the pointer to subtlv_len i.e. uncomment below line and add it in the code // stream_forward_getp(s, subtlv_len); } . . . . . . } Note: In unpack_item_ext_subtlvs(), there are other "case" as well that needs the same 2 fix Thanks, Himanshu Rai