14. IS-IS Common Header Compass-EOS Confidential Packet Data … Definition Values network layer identifier assigned to IS-IS (ISO 9577) 0x83 Length of the packet header fields in octets Variable Version 0x1 Indicates length of the source ID (SysID) field 0x0 -> 6 byte IS-IS packet type (3 bits reserved) Hello, LSP or SNP Version 0x1 Reserved 0 Number of area addresses permitted for this intermediate system’s area 0x0 = max 3 areas
19. IIH – LAN Level 1 and Level 2 Compass-EOS Confidential Field Definition Circuit type Level 1, Level 1-2, or Level 2 only (6 bit reserved) Source ID System ID of the router that generated packet Holding time Maximum interval between two consecutive hello packets before the router is considered no longer available PDU length Length of the entire PDU, including header Priority designates the DIS (Level 1 or Level 2) on the LAN LAN ID SysID of the DIS plus an octet-long unique ID for this router assigned by the DIS. TLV fields Type 1 - Area Addresses Type 6 - IS Neighbors Type 8 - Padding Type 10 - Authentication Type
In OSPF all timers must align with the DR (designated router) July 10, 2000
Any change in network conditions causing changes in TLV information advertised in the most recent hello transmitted ID length in the IIH. This field indicates the length of the SysID and the SysID must be consistent on all routers across the domain Maximum number of areas. addresses supported in a single router configuration must match between adjacent neighbors, default maximum value of 3. July 10, 2000
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POP - close collection of routers July 10, 2000
POP - close collection of routers July 10, 2000
If pseudo-node ID is 00 it means that this is a real router. Since IS-IS is on layer 2 there is no fragmentation service, do it is part of the IS-IS itself July 10, 2000
If pseudo-node ID is 00 it means that this is a real router. Since IS-IS is on layer 2 there is no fragmentation service, do it is part of the IS-IS itself July 10, 2000
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Synchronizing DB and resulting routing tables is crucial for bringing packets closer to their destination. CSNP by default is sends every 10 seconds. Can be configured. CSNP can be more than one packet. Start and end LAN-ID is used to identify it: 0000.0000.0000.00-00 to ffff.ffff.ffff.ff-ff SRM – set on a link the corresponding LSP has to be sent out on that link. SSN – the corresponding LSP should be included in the next PSNP Behavior when CSNP reporting an older version of the LSP\\a more recent version of LSP\\ an unknown LSP July 10, 2000
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TLV - Type Length Value Authentication is applied on the entire PDU July 10, 2000