Differences between version 10 and previous revision of ISIS.
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| Newer page: | version 10 | Last edited on Sunday, August 22, 2004 11:20:08 am | by LindsayDruett | Revert |
| Older page: | version 9 | Last edited on Monday, August 16, 2004 9:28:02 pm | by LindsayDruett | Revert |
@@ -52,8 +52,36 @@
Router#__debug isis spf-statistics__
''- Displays statistical information about building routes between routers''
Router#__debug isis update-packets__
''- Displays SNPs (CSNPs and PSNPs) and LSPs that are detected by the router''
+
+----
+!!ISO Addressing for IS-IS
+
+The ISO address is a variable-length address from 8-20 octets in length. There are three sections to an ISO address...
+
+|__AREA__|__ID__|__SEL__
+
+*__Area__
+**The Area field is used to route between areas using Level 2 routing.
+*__ID__
+**The ID field is used to route to a host or router within the area using Level 1 routing.
+*__SEL__
+**The SEL field is used to route to an entity with the host or ES.
+
+An ISO Address...
+
+|__IDP Part__|__IDP Part__|__DSP Part__|__DSP Part__|__DSP Part__
+|AFI|IDI|High Order DSP|System ID|NSEL
+|''Area''|''Area''|''Area''|''ID''|''SEL''
+
+*__IDP__ - Initial Domain Part. The IDP is used to route to the domain (or autonomous system). The IDP is given by the ISO and identifies the organization responsible for assigning the format for the rest of the address by defining the DSP structure.
+**__AFI__ - Authority and Format Identifier. The AFI is the first octet of the address. It is defined as one octet. It states the authority in charge of issuing addresses and the format of the rest of the address, within the contraints of IDI and DSP, to describle Area, ID, and SEL.
+**__IDI__ - Initial Domain Identifier.The IDI is the suborganization to the AFI.
+*__DSP__ - Domain Specific Part. The DSP is used to route within the autonomous system. The authority specified by the IDP may further subdivide the DSP and may assign subauthorities responsible for parts of the DSP.
+**__High Order DSP__ - High Order DSP is typically the area within the autonomous system.
+**__System ID__ - System ID can have a value between 1 and 8 octets. It must have the same length throughout all systems in the autonomous system. Cisco for example uses 6 octets, which is a common solution because it allows the use of the MAC Address to autoconfigure the system.
+**__NSEL__ - NSEL is one byte and identifies the particular service at the network layer to which to hand the packet.
----
!!IS-IS Terms
|Adjacency|Local routing information that shows the reachability of a directly connect End System (ES)- Node or Intermediate System (IS) - Router. A separate adjacency is created for each neighbor on a circuit, and for each level of routing (that is Level 1 and Level 2) on a broadcast circuit.
