Hello Packets

Figure A-1. LAN Level-1 hello packet format (PDU Type 15).

Example A-1 Analyzer Capture: LAN Level-1 Hello Packet

 ADDR  HEX                                               ASCII 0000: 01 80 c2 00 00 14 00 d0 58 f7 89 41 05 dc fe fe  .....DX  A.ww 0010: 03 83 1b 01 00 0f 01 00 00 03 00 00 00 00 00 01  .  .............. 0020: 00 0a 05 d9 40 00 00 00 00 00 01 01 81 01 cc 01  ...@.......... 0030: 04 03 49 00 01 84 04 0a 01 01 01 06 0c 00 d0 58  ..I.."........DX 0040: eb f8 41 00 d0 58 eb ff 01 08 ff 00 00 00 00 00  A.DX....... 0050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................ 0060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................ 0070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................ 0080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................ 0090: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................ 00a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................ 00b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................ 00c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................ 00d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................ 00e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................ 00f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................ 0100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................ 0110: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................ 0120: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................ 0130: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................ 0140: 00 00 00 00 00 00 00 00 00 00 

Example A-2 Decode of Example A-1 (Part 1)

 DLC:  ----- DLC Header -----       DLC:       DLC:  Frame 1 arrived at  19:03:01.2025; frame size is 1514 (05EA hex) bytes.       DLC:  Destination = Multicast 0180C2000014       DLC:  Source      = Station 00D058F78941       DLC:  802.3 length = 1500       DLC: LLC:  ----- LLC Header -----       LLC:       LLC:  DSAP Address = FE, DSAP IG Bit = 00 (Individual Address)       LLC:  SSAP Address = FE, SSAP CR Bit = 00 (Command)       LLC:  Unnumbered frame: UI 

Example A-3 Decode of Example A-1 (Part 2)

 IS-IS: ----- ISO Network Layer Header -----       IS-IS:       IS-IS: Protocol ID = 83 (Intermediate System Routing Exchange Protocol)       IS-IS: Header length = 27       IS-IS: Version / Protocol ID Extension = 1       IS-IS: ID Length = 0, Indicates 6 Octets       IS-IS: PDU type = 15  (Hello, LAN Level 1)       IS-IS: Version = 1       IS-IS: Reserved = 0       IS-IS: Maximum Area Addesses = 0       IS-IS: Circuit Type = 3  (Both level 1 and level 2 routing)       IS-IS: Source ID = 000000000001       IS-IS: Holding time is 10 second(s)       IS-IS: Frame length is 1497 byte(s)       IS-IS: Designated Intermediate System for Level 1       IS-IS:   Priority = 64       IS-IS:   Address = 000000000001       IS-IS:   ID = 01 

Example A-4 Decode of Example A-1 (Part 3)

 IS-IS: ----- ISO Network Layer Variable Fields -----       IS-IS:       IS-IS: Variable field:       IS-IS:   Field Code = 129  (Protocols Supported)       IS-IS:   Field length = 1       IS-IS:   NLPID'sfor protocols within this IS:       IS-IS:     NLPID = CC (Internet IP)       IS-IS: Variable field:       IS-IS:   Field Code = 1  (Manual Area Addresses)       IS-IS:   Field length = 4       IS-IS:   Manual Area Address:       IS-IS:     Length  = 3       IS-IS:     Format  = 49 (Local Binary)       IS-IS:     Address = 490001       IS-IS: Variable field:       IS-IS:   Field Code = 132  (IP Interface Address)       IS-IS:   Field length = 4       IS-IS:   IP Interface Address:       IS-IS:     IP Address = [10.1.1.1]       IS-IS: Variable field:       IS-IS:   Field Code = 6  (System Neighbors)       IS-IS:   Field length = 12       IS-IS:   Neighbor = 00D058EBF841       IS-IS:   Neighbor = 00D058EBFF01       IS-IS: Variable field:       IS-IS:   Field Code = 8  (Padding)       IS-IS:   Field length = 255 

Figure A-2. LAN Level-2 hello packets (PDU Type 16).

Example A-5 Analyzer Capture: LAN Level-2 Hello Packet

 ADDR  HEX                                               ASCII 0000: 01 80 c2 00 00 15 00 d0 58 f7 89 41 05 dc fe fe ....DX  A.ww 0010: 03 83 1b 01 00 10 01 00 00 03 00 00 00 00 00 01  .  .............. 0020: 00 0a 05 d9 40 00 00 00 00 00 01 01 81 01 cc 01  ...@.......?.. 0030: 04 03 49 00 01 84 04 0a 01 01 01 06 06 00 d0 58  ..I.."........DX 0040: eb f8 41 

Example A-6 Decode of Example A-5 (LAN Level-2 Hello Packet)

 IS-IS: -----ISO Network Layer Header -----       IS-IS:       IS-IS: Protocol ID = 83 (Intermediate System Routing Exchange Protocol)       IS-IS: Header length = 27       IS-IS: Version / Protocol ID Extension = 1       IS-IS: ID Length = 0, Indicates 6 Octets       IS-IS: PDU type = 16  (Hello, LAN Level 2)       IS-IS: Version = 1       IS-IS: Reserved = 0       IS-IS: Maximum Area Addesses = 0       IS-IS: Circuit Type = 3  (Both level 1 and level 2 routing)       IS-IS: Source ID = 000000000001       IS-IS: Holding time is 10 second(s)       IS-IS: Frame length is 1497 byte(s)       IS-IS: Designated Intermediate System for Level 2       IS-IS:   Priority = 64       IS-IS:   Address = 000000000001       IS-IS:   ID = 01 

Figure A-3. Point-to-point hello packets (PDU Type 17).