HPE 5800 Series Configuration Manual page 128

Common header format
Figure 40 PDU common header format
Intradomain routing protocol discriminator
Version/Protocol ID extension
R R
Major fields of the PDU common header are:
•
Intradomain routing protocol discriminator—Set to 0x83.
•
Length indicator—Length of the PDU header in bytes, including both common and specific
headers.
•
Version/Protocol ID extension—Set to 1(0x01).
•
ID length—Length of the NSAP address and NET ID.
•
R (Reserved)—Set to 0.
•
PDU type—For detailed information, see
•
Version—Set to 1(0x01).
•
Maximum area address—Maximum number of area addresses supported.
Table 4 PDU types
Type
15
16
17
18
20
24
25
26
27
Hello PDU
IS-to-IS hello PDUs (IIHs) are used by routers to establish and maintain neighbor relationships. On
broadcast networks, the Level-1 routers use the Level-1 LAN IIHs, and the Level-2 routers use the
Level-2 LAN IIHs. The P2P IIHs are used on point-to-point networks.
Figure 41 illustrates the hello packet format in broadcast networks, where the blue fields are the
common header.
Length indicator
ID length
R PDU type
Version
Reserved
Maximum area address
PDU Type
Level-1 LAN IS-IS hello PDU
Level-2 LAN IS-IS hello PDU
Point-to-Point IS-IS hello PDU
Level-1 Link State PDU
Level-2 Link State PDU
Level-1 Complete Sequence Numbers PDU
Level-2 Complete Sequence Numbers PDU
Level-1 Partial Sequence Numbers PDU
Level-2 Partial Sequence Numbers PDU
No. of Octets
1
1
1
1
1
1
1
1
Table 4.
117
Acronym
L1 LAN IIH
L2 LAN IIH
P2P IIH
L1 LSP
L2 LSP
L1 CSNP
L2 CSNP
L1 PSNP
L2 PSNP