IS-IS - Intermediate System to Intermediate System
    • IS-IS เหมาะสำหรับ เครือข่ายขนาดใหญ่ อย่างพวก Service Provider

    • ข้อแตกต่างระหว่าง OSPF และ IS-IS:

    • In OSI Terminology, a router = an intermediate system (IS). A router is a member of only 1 Area.

    • IS-IS was the routing protocol created for OSI:
      • OSPF = TCP/IP
      • IS-IS = OSI

    • Requires an OSI Address, called a ConnectionLess Network Services (CLNS) address, to function.

    • Uses SPF.

    • More Tunable, Efficient, and Flexible than OSPF

    • L1: member of only 1 area
      L2: backbone router. They know the backbone but not their own area. It represents the Core Network.
      L1/L2: member of an area and of the backbone. They summarize route of their own area to the backbone.
      A L1 router contacts a L2 router to go to another area.


    • Configuring Integrated IS-IS, IS-IS Configuration Task List, Enable IS-IS, Configure IS-IS Interface Parameters, Miscellaneous IS-IS

    Network entity title (NET), NSAP Address

    IS-IS Terminology

    • [li]interface mtu ต้องเท่ากัน[/li]
      [li]clns mtu ต้องเท่ากัน[/li]

    key chain Area1 -> Key-Chain Name = Area1
    key 1 -> Key-ID "1"
      key-string cisco123 -> Password = cisco123
    interface TenGigabitEthernet1/1
    ip router isis
    isis authentication mode md5 -> Authentication Mode = Message Digest
    isis authentication key-chain Area1 -> Authentication = Hello Packet Authentication
    router isis
    net 49.0001.0000.0000.0011.00
    is-type level-2-only -> IS-Type = Level 2 Only
    metric-style wide -> Metric Style = Wide
    passive-interface Loopback0


    • %CLNS-5-ADJCHANGE: ISIS: Adjacency to xxx (GigabitEthernet1/1/2) Down, neighbor forgot us: Configure "isis network point-to-point" แล้วสามารถแก้ปัญหาได้

    • %CLNS-4-AUTH_FAIL: ISIS: Serial IIH authentication failed: ตรวจสอบขาที่ isis neighbour ไม่ up ใส่ authentication ให้ถูกต้อง

      R1#deb isi adj
      061163: Oct  5 16:34:05.565 bkk: ISIS-Adj: Rec serial IIH from 4562.882a.4b5a (TenGigabitEthernet1/3), cir type L2, cir id 00, length 1496
      061164: Oct  5 16:34:05.565 bkk: ISIS-Adj: Authentication failed
      061228: Oct  5 16:34:14.649 bkk: ISIS-Adj: Rec serial IIH from 4562.882a.4b5a (TenGigabitEthernet1/3), cir type L2, cir id 00, length 1496
      061229: Oct  5 16:34:14.649 bkk: %CLNS-4-AUTH_FAIL: ISIS: Serial IIH authentication failed

      R1#un all

      R1#sho isis neighbor | inc 1/3

      Compare isis interface configuration both side. If the configuration is corrected, re-configure int te1/3.
      Cr: P'Teng@AIT

    • Init State:

      • XR# debug isis adjacencies interface x
        RP/0/RSP0/CPU0:Oct 11 11:28:12.170 BKK: isis[1014]: SEND P2P IIH (L2) on Bundle-Ether9: Holdtime 30s, Length 9199
        RP/0/RSP0/CPU0:Oct 11 11:28:12.357 BKK: isis[1014]: RECV P2P IIH (L2) from Bundle-Ether9 SNPA 40ce.2418.9b52: System ID PN2, Holdtime 30, length 9198

      • Nokia# debug router isis packet ptop-hello "Interface-Name"
        configure log log-id 1 from debug-trace
        configure log log-id 1 to session
        * ptop-hello = p2p link - hello packet