isis: add configuration commands and their explanations

1 files changed, 233 insertions, 6 deletions

diff --git a/docs/configuration/protocols/isis.rst b/docs/configuration/protocols/isis.rst
index 753637f9..71ddc856 100644
--- a/docs/configuration/protocols/isis.rst
+++ b/docs/configuration/protocols/isis.rst
@@ -7,12 +7,13 @@ 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
+interior gateway routing protocol which is described in ISO10589,
+:rfc:`1195`, :rfc:`5308`. 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)`
@@ -36,6 +37,232 @@ The IS-IS address consists of three parts:
   NET selector:
     ``00`` Must always be 00, to indicate "this system".
 
+
+General Configuration
+---------------------
+
+.. cfgcmd:: set protocols isis <name> net <network-entity-title>
+
+  This command enables the ISIS process by specifying the ISIS domain with
+  ‘name’. ISIS implementation does not yet support multiple ISIS processes
+  but you must specify the name of ISIS process. This commad also sets
+  network entity title (NET) provided in ISO format.
+
+.. cfgcmd:: set protocols isis <name> interface <interface>
+
+  This command activates ISIS adjacency on this interface. Note that the name
+  of ISIS instance must be the same as the one used to configure the ISIS
+  process.
+  
+.. cfgcmd:: set protocols isis <name> dynamic-hostname
+
+  This command enables support for dynamic hostname. Dynamic hostname mapping
+  determined as described in :rfc:`2763`, Dynamic Hostname Exchange Mechanism
+  for IS-IS.
+
+.. cfgcmd:: set protocols isis <name> level <level-1|level-1-2|level-2>
+
+  This command defines the ISIS router behavior:
+
+      **level-1** Act as a station router only.
+      **level-1-2** Act as both a station router and an area router.
+      **level-2-only** Act as an area router only.
+
+.. cfgcmd:: set protocols isis <name> lsp-mtu <size>
+
+  This command configures the maximum size of generated LSPs, in bytes. The
+  size range is 128 to 4352.
+
+.. cfgcmd:: set protocols isis <name> metric-style <narrow|transition|wide>
+
+  This command sets old-style (ISO 10589) or new-style packet formats:
+
+      **narrow** Use old style of TLVs with narrow metric.
+      **transition** Send and accept both styles of TLVs during transition.
+      **wide** Use new style of TLVs to carry wider metric.
+
+.. cfgcmd:: set protocols isis <name> purge-originator
+
+  This command enables :rfc:`6232` purge originator identification. Enable
+  purge originator identification (POI) by adding the type, length and value
+  (TLV) with the Intermediate System (IS) identification to the LSPs that do
+  not contain POI information. If an IS generates a purge, VyOS adds this TLV
+  with the system ID of the IS to the purge. 
+
+.. cfgcmd:: set protocols isis <name> set-attached-bit
+
+  This command sets ATT bit to 1 in Level1 LSPs. It is described in :rfc:`3787`.
+
+.. cfgcmd:: set protocols isis <name> set-overload-bit
+
+  This command sets overload bit to avoid any transit traffic through this
+  router. It is described in :rfc:`3787`.
+
+.. cfgcmd:: set protocols isis name default-information originate <ipv4|ipv6>
+  level-1
+
+  This command will generate a default-route in L1 database.
+  
+.. cfgcmd:: set protocols isis name default-information originate <ipv4|ipv6>
+  level-2
+
+  This command will generate a default-route in L2 database.
+
+
+Interfaces Configuration
+------------------------
+
+.. cfgcmd:: set protocols isis <name> interface <interface> circuit-type
+  <level-1|level-1-2|level-2-only>
+
+  This command specifies circuit type for interface:
+
+      **level-1** Level-1 only adjacencies are formed.
+      **level-1-2** Level-1-2 adjacencies are formed
+      **level-2-only** Level-2 only adjacencies are formed
+
+.. cfgcmd:: set protocols isis <name> interface <interface> hello-interval
+  <seconds>
+
+  This command sets hello interval in seconds on a given interface.
+  The range is 1 to 600.
+
+.. cfgcmd:: set protocols isis <name> interface <interface> hello-multiplier
+  <seconds>
+
+  This command sets multiplier for hello holding time on a given 
+  interface. The range is 2 to 100.
+
+.. cfgcmd:: set protocols isis <name> interface <interface> hello-padding
+
+  This command configures padding on hello packets to accommodate asymmetrical
+  maximum transfer units (MTUs) from different hosts as described in
+  :rfc:`3719`. This helps to prevent a premature adjacency Up state when one
+  routing device’s MTU does not meet the requirements to establish the
+  adjacency. 
+
+.. cfgcmd:: set protocols isis <name> interface <interface> metric <metric>
+
+  This command set default metric for circuit. The metric range is 1 to 
+  16777215 (Max value depend if metric support narrow or wide value).
+
+.. cfgcmd:: set protocols isis <name> interface <interface> network
+  point-to-point
+
+  This command specifies network type to ‘Point-to-Point’. The default network
+  type is broadcast.
+
+.. cfgcmd:: set protocols isis <name> interface <interface> passive
+
+  This command configures the passive mode for this interface.
+
+.. cfgcmd:: set protocols isis <name> interface <interface> password
+  plaintext-password <text>
+
+  This command configures the authentication password for the interface.
+
+.. cfgcmd:: set protocols isis <name> interface <interface> priority <number>
+
+  This command sets priority for the interface for
+  :abbr:`DIS (Designated Intermediate System)` election. The priority
+  range is 0 to 127.
+
+.. cfgcmd:: set protocols isis <name> interface <interface> psnp-interval
+  <number>
+
+  This command sets PSNP interval in seconds. The interval range is 0
+  to 127.
+
+.. cfgcmd:: set protocols isis <name> interface <interface>
+  three-way-handshake
+
+  This command enables :rfc:`5303` Three-Way Handshake for P2P adjacencies.
+  Three-Way Handshake is enabled by default.
+
+
+Redistribution Configuration
+----------------------------
+
+.. cfgcmd:: set protocols isis <name> redistribute ipv4 <route source> level-1
+
+  This command redistributes routing information from the given route source
+  into the ISIS database as Level-1. There are six modes available for route
+  source: bgp, connected, kernel, ospf, rip, static.
+
+.. cfgcmd:: set protocols isis <name> redistribute ipv4 <route source> level-2
+
+  This command redistributes routing information from the given route source
+  into the ISIS database as Level-2. There are six modes available for route
+  source: bgp, connected, kernel, ospf, rip, static.
+   
+.. cfgcmd:: set protocols isis <name> redistribute ipv4 <route source>
+  <level-1|level-2> metric <number>
+
+  This command specifies metric for redistributed routes from the given route
+  source. There are six modes available for route source: bgp, connected,
+  kernel, ospf, rip, static. The metric range is 1 to 16777215.
+
+.. cfgcmd:: set protocols isis <name> redistribute ipv4 <route source>
+  <level-1|level-2> route-map <name>
+
+  This command allows to use route map to filter redistributed routes from
+  the given route source. There are six modes available for route source:
+  bgp, connected, kernel, ospf, rip, static.
+
+
+Timers Configuration
+--------------------
+
+.. cfgcmd:: set protocols isis <name> lsp-gen-interval <seconds>
+
+  This command sets minimum interval in seconds between regenerating same
+  LSP. The interval range is 1 to 120.
+  
+.. cfgcmd:: set protocols isis <name> lsp-refresh-interval <seconds>
+
+  This command sets LSP refresh interval in seconds. IS-IS generates LSPs
+  when the state of a link changes. However, to ensure that routing
+  databases on all routers remain converged, LSPs in stable networks are
+  generated on a regular basis even though there has been no change to
+  the state of the links. The interval range is 1 to 65235. The default
+  value is 900 seconds.
+
+.. cfgcmd:: set protocols isis <name> max-lsp-lifetime <seconds>
+
+  This command sets LSP maximum LSP lifetime in seconds. The interval range
+  is 350 to 65535. LSPs remain in a database for 1200 seconds by default.
+  If they are not refreshed by that time, they are deleted. You can change
+  the LSP refresh interval or the LSP lifetime. The LSP refresh interval
+  should be less than the LSP lifetime or else LSPs will time out before
+  they are refreshed. 
+  
+.. cfgcmd:: set protocols isis <name> spf-interval <seconds>
+
+  This command sets minimum interval between consecutive SPF calculations in
+  seconds.The interval range is 1 to 120.
+
+.. cfgcmd:: set protocols isis <name> spf-delay-ietf holddown <milliseconds>
+
+.. cfgcmd:: set protocols isis <name> spf-delay-ietf init-delay 
+  <milliseconds>
+
+.. cfgcmd:: set protocols isis <name> spf-delay-ietf long-delay 
+  <milliseconds>
+
+.. cfgcmd:: set protocols isis <name> spf-delay-ietf short-delay 
+  <milliseconds>
+
+.. cfgcmd:: set protocols isis <name> spf-delay-ietf time-to-learn 
+  <milliseconds>
+
+  This commands specifies the Finite State Machine (FSM) intended to
+  control the timing of the execution of SPF calculations in response
+  to IGP events. The process described in :rfc:`8405`.
+
+
+Configuration Example
+---------------------
+
 Simple IS-IS configuration using 2 nodes and redistributing connected
 interfaces.