mirror of
https://github.com/vyos/vyos-documentation.git
synced 2025-10-26 08:41:46 +01:00
79 lines
2.4 KiB
ReStructuredText
79 lines
2.4 KiB
ReStructuredText
.. include:: /_include/need_improvement.txt
|
||
|
||
.. _isis:
|
||
|
||
#####
|
||
IS-IS
|
||
#####
|
||
|
||
:abbr:`IS-IS (Intermediate System to Intermediate System)` is a link-state
|
||
interior gateway routing protocol. Like OSPF, IS-IS runs the Dijkstra
|
||
shortest-path first (SPF) algorithm to create a database of the network’s
|
||
topology and, from that database, to determine the best (that is, shortest)
|
||
path to a destination. The routers exchange topology information with their
|
||
nearest neighbors. IS-IS runs directly on the data link layer (Layer 2).
|
||
IS-IS addresses are called :abbr:`NETs (Network Entity Titles)` and can be
|
||
8 to 20 bytes long, but are generally 10 bytes long.
|
||
|
||
For example :abbr:`NET (Network Entity Title)`
|
||
|
||
.. code-block:: none
|
||
|
||
49.0001.1921.6800.1002.00
|
||
|
||
The IS-IS address consists of three parts:
|
||
|
||
:abbr:`AFI (Address family authority identifier)`
|
||
``49`` The AFI value 49 is what IS-IS uses for private addressing.
|
||
|
||
Area identifier:
|
||
``0001`` IS-IS area number (Area1)
|
||
|
||
System identifier:
|
||
``1921.6800.1002`` For system idetifier we recommend to use IP address or
|
||
MAC address of the router.
|
||
|
||
NET selector:
|
||
``00`` Must always be 00, to indicate "this system".
|
||
|
||
Simple IS-IS configuration using 2 nodes and redistributing connected
|
||
interfaces.
|
||
|
||
**Node 1:**
|
||
|
||
.. code-block:: none
|
||
|
||
set interfaces dummy dum0 address '203.0.113.1/24'
|
||
set interfaces ethernet eth1 address '192.0.2.1/24'
|
||
|
||
set policy prefix-list EXPORT-ISIS rule 10 action 'permit'
|
||
set policy prefix-list EXPORT-ISIS rule 10 prefix '203.0.113.0/24'
|
||
set policy route-map EXPORT-ISIS rule 10 action 'permit'
|
||
set policy route-map EXPORT-ISIS rule 10 match ip address prefix-list 'EXPORT-ISIS'
|
||
|
||
set protocols isis FOO interface eth1
|
||
set protocols isis FOO net '49.0001.1921.6800.1002.00'
|
||
set protocols isis FOO redistribute ipv4 connected level-2 route-map 'EXPORT-ISIS'
|
||
|
||
**Node 2:**
|
||
|
||
.. code-block:: none
|
||
|
||
set interfaces ethernet eth1 address '192.0.2.2/24'
|
||
|
||
set protocols isis FOO interface eth1
|
||
set protocols isis FOO net '49.0001.1921.6800.2002.00'
|
||
|
||
Show ip routes on Node2:
|
||
|
||
.. code-block:: none
|
||
|
||
vyos@r2:~$ show ip route isis
|
||
Codes: K - kernel route, C - connected, S - static, R - RIP,
|
||
O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP,
|
||
T - Table, v - VNC, V - VNC-Direct, A - Babel, D - SHARP,
|
||
F - PBR, f - OpenFabric,
|
||
> - selected route, * - FIB route, q - queued route, r - rejected route
|
||
|
||
I 203.0.113.0/24 [115/10] via 192.0.2.1, eth1, 00:03:42
|