Segment-rounting : Fixed documetation and add exammple

3 files changed, 343 insertions, 270 deletions

diff --git a/docs/configexamples/index.rst b/docs/configexamples/index.rst
index 7f6e56a5..087fd646 100644
--- a/docs/configexamples/index.rst
+++ b/docs/configexamples/index.rst
@@ -20,6 +20,7 @@ This chapter contains various configuration examples:
    inter-vrf-routing-vrf-lite
    openvpn-ldap
    qos
+   segment-routing-isis
 
 
 Configuration Blueprints (autotest)
diff --git a/docs/configexamples/segment-routing-isis.rst b/docs/configexamples/segment-routing-isis.rst
new file mode 100644
index 00000000..d9bc439b
--- /dev/null
+++ b/docs/configexamples/segment-routing-isis.rst
@@ -0,0 +1,279 @@
+:lastproofread: 2023-04-10
+
+.. _examples-segment-routing-isis:
+
+#############################
+Segment-routing IS-IS example
+#############################
+
+When utilizing VyOS in an environment with Cisco IOS-XR gear you can use this 
+blue print as an initial setup to get MPLS ISIS-SR working between those two 
+devices.The lab was build using :abbr:`EVE-NG (Emulated Virtual
+Environment NG)`.
+
+.. figure:: /_static/images/vyos-sr-isis.png
+   :alt: ISIS-SR network
+
+   ISIS-SR example network
+
+The below configuration is used as example where we keep focus on 
+VyOS-P1/VyOS-P2/XRv-P3 which we share the settings.
+
+
+Configuration
+=============
+
+- VyOS-P1:
+
+.. code-block:: none
+
+  set interfaces dummy dum0 address '192.0.2.1/32'
+  set interfaces ethernet eth1 address '192.0.2.5/30'
+  set interfaces ethernet eth1 mtu '8000'
+  set interfaces ethernet eth3 address '192.0.2.21/30'
+  set interfaces ethernet eth3 mtu '8000'
+  set protocols isis interface dum0 passive
+  set protocols isis interface eth1 network point-to-point
+  set protocols isis interface eth3 network point-to-point
+  set protocols isis level 'level-2'
+  set protocols isis log-adjacency-changes
+  set protocols isis metric-style 'wide'
+  set protocols isis net '49.0000.0000.0000.0001.00'
+  set protocols isis segment-routing maximum-label-depth '8'
+  set protocols isis segment-routing prefix 192.0.2.1/32 index value '1'
+  set protocols mpls interface 'eth1'
+  set protocols mpls interface 'eth3'
+  set system host-name 'P1-VyOS'
+
+- XRv-P3:
+
+.. code-block:: none
+
+  hostname P3-VyOS
+  interface Loopback0
+   ipv4 address 192.0.2.3 255.255.255.255
+  !
+  interface GigabitEthernet0/0/0/1
+   mtu 8014
+   ipv4 address 192.0.2.6 255.255.255.252
+  !
+  interface GigabitEthernet0/0/0/2
+   mtu 8014
+   ipv4 address 192.0.2.18 255.255.255.252
+  !
+  router isis VyOS
+   is-type level-2-only
+   net 49.0000.0000.0000.0003.00
+   log adjacency changes
+   address-family ipv4 unicast
+    metric-style wide
+    segment-routing mpls
+   !
+   interface Loopback0
+    passive
+    address-family ipv4 unicast
+     prefix-sid index 3
+    !
+   !
+   interface GigabitEthernet0/0/0/1
+    point-to-point
+    address-family ipv4 unicast
+    !
+   !
+   interface GigabitEthernet0/0/0/2
+    point-to-point
+    address-family ipv4 unicast
+    !
+   !
+  !
+
+- VyOS-P2:
+
+.. code-block:: none
+  
+  set interfaces dummy dum0 address '192.0.2.2/32'
+  set interfaces ethernet eth2 address '192.0.2.17/30'
+  set interfaces ethernet eth2 mtu '8000'
+  set interfaces ethernet eth3 address '192.0.2.26/30'
+  set interfaces ethernet eth3 mtu '8000'
+  set protocols isis interface dum0 passive
+  set protocols isis interface eth2 network point-to-point
+  set protocols isis interface eth3 network point-to-point
+  set protocols isis level 'level-2'
+  set protocols isis log-adjacency-changes
+  set protocols isis metric-style 'wide'
+  set protocols isis net '49.0000.0000.0000.0002.00'
+  set protocols isis segment-routing maximum-label-depth '8'
+  set protocols isis segment-routing prefix 192.0.2.2/32 index value '2'
+  set protocols mpls interface 'eth2'
+  set protocols mpls interface 'eth3'
+  set system host-name 'P2-VyOS'
+
+This gives us MPLS segment routing enabled and labels forwarding :
+
+.. code-block:: none
+  
+   vyos@P1-VyOS:~$ show mpls table
+   Inbound Label  Type        Nexthop               Outbound Label
+   -----------------------------------------------------------------
+   15000          SR (IS-IS)  192.0.2.6             implicit-null
+   15001          SR (IS-IS)  192.0.2.22            implicit-null
+   15002          SR (IS-IS)  fe80::5200:ff:fe04:3  implicit-null
+   16002          SR (IS-IS)  192.0.2.6             16002
+   16003          SR (IS-IS)  192.0.2.6             implicit-null
+   16011          SR (IS-IS)  192.0.2.22            implicit-null
+  
+   vyos@P2-VyOS:~$ show mpls table
+   Inbound Label  Type        Nexthop     Outbound Label
+   -------------------------------------------------------
+   15000          SR (IS-IS)  192.0.2.18  implicit-null
+   16001          SR (IS-IS)  192.0.2.18  16001
+   16003          SR (IS-IS)  192.0.2.18  implicit-null
+   16011          SR (IS-IS)  192.0.2.18  16011
+
+   RP/0/0/CPU0:P3-VyOS#show mpls forwarding
+   Tue Mar 28 17:47:18.928 UTC
+   Local  Outgoing    Prefix             Outgoing     Next Hop        Bytes
+   Label  Label       or ID              Interface                    Switched
+   ------ ----------- ------------------ ------------ --------------- ------------
+   16001  Pop         SR Pfx (idx 1)     Gi0/0/0/1    192.0.2.5       0
+   16002  Pop         SR Pfx (idx 2)     Gi0/0/0/2    192.0.2.17      0
+   16011  16011       SR Pfx (idx 11)    Gi0/0/0/1    192.0.2.5       0
+   24000  Pop         SR Adj (idx 1)     Gi0/0/0/1    192.0.2.5       0
+   24001  Pop         SR Adj (idx 3)     Gi0/0/0/1    192.0.2.5       0
+   24002  Pop         SR Adj (idx 1)     Gi0/0/0/2    192.0.2.17      0
+   24003  Pop         SR Adj (idx 3)     Gi0/0/0/2    192.0.2.17      0
+
+
+VyOS is able to check MSD per devices: 
+
+.. code-block:: none
+
+   vyos@P1-VyOS:~$ show isis segment-routing node
+   Area VyOS:
+   IS-IS L1 SR-Nodes:
+  
+   IS-IS L2 SR-Nodes:
+  
+   System ID       SRGB           SRLB            Algorithm  MSD
+   ---------------------------------------------------------------
+   0000.0000.0001  16000 - 23999  15000 - 15999   SPF        8
+   0000.0000.0002  16000 - 23999  15000 - 15999   SPF        8
+   0000.0000.0003  16000 - 23999  0 - 4294967295  SPF        10
+   0000.0000.0011  16000 - 23999  15000 - 15999   SPF        8
+
+   vyos@P2-VyOS:~$ show isis segment-routing node
+   Area VyOS:
+    IS-IS L1 SR-Nodes:
+   
+    IS-IS L2 SR-Nodes:
+   
+    System ID       SRGB           SRLB            Algorithm  MSD
+    ---------------------------------------------------------------
+    0000.0000.0001  16000 - 23999  15000 - 15999   SPF        8
+    0000.0000.0002  16000 - 23999  15000 - 15999   SPF        8
+    0000.0000.0003  16000 - 23999  0 - 4294967295  SPF        10
+    0000.0000.0011  16000 - 23999  15000 - 15999   SPF        8
+
+Here is the routing tables showing the MPLS segment routing label operations:
+
+.. code-block:: none
+
+   vyos@P1-VyOS:~$ 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, F - PBR,
+          f - OpenFabric,
+          > - selected route, * - FIB route, q - queued, r - rejected, b - backup
+          t - trapped, o - offload failure
+   
+   I>* 192.0.2.2/32 [115/30] via 192.0.2.6, eth1, label 16002, weight 1, 1d03h18m
+   I>* 192.0.2.3/32 [115/10] via 192.0.2.6, eth1, label implicit-null, weight 1, 1d03h18m
+   I   192.0.2.4/30 [115/20] via 192.0.2.6, eth1 inactive, weight 1, 1d03h18m
+   I>* 192.0.2.11/32 [115/20] via 192.0.2.22, eth3, label implicit-null, weight 1, 1d02h47m
+   I>* 192.0.2.16/30 [115/20] via 192.0.2.6, eth1, weight 1, 1d03h18m
+   I   192.0.2.20/30 [115/20] via 192.0.2.22, eth3 inactive, weight 1, 1d02h48m
+   I>* 192.0.2.24/30 [115/30] via 192.0.2.6, eth1, weight 1, 1d03h18m
+   
+   
+   vyos@P2-VyOS:~$ 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, F - PBR,
+          f - OpenFabric,
+          > - selected route, * - FIB route, q - queued, r - rejected, b - backup
+          t - trapped, o - offload failure
+   
+   I>* 192.0.2.1/32 [115/30] via 192.0.2.18, eth2, label 16001, weight 1, 1d03h17m
+   I>* 192.0.2.3/32 [115/10] via 192.0.2.18, eth2, label implicit-null, weight 1, 1d03h17m
+   I>* 192.0.2.4/30 [115/20] via 192.0.2.18, eth2, weight 1, 1d03h17m
+   I>* 192.0.2.11/32 [115/40] via 192.0.2.18, eth2, label 16011, weight 1, 1d02h47m
+   I   192.0.2.16/30 [115/20] via 192.0.2.18, eth2 inactive, weight 1, 1d03h17m
+   I>* 192.0.2.20/30 [115/30] via 192.0.2.18, eth2, weight 1, 1d03h17m
+   
+   RP/0/0/CPU0:P3-VyOS#show route isis
+   Tue Mar 28 18:19:16.417 UTC
+   
+   i L2 192.0.2.1/32 [115/20] via 192.0.2.5, 1d03h, GigabitEthernet0/0/0/1
+   i L2 192.0.2.2/32 [115/20] via 192.0.2.17, 1d03h, GigabitEthernet0/0/0/2
+   i L2 192.0.2.11/32 [115/30] via 192.0.2.5, 1d02h, GigabitEthernet0/0/0/1
+   i L2 192.0.2.20/30 [115/20] via 192.0.2.5, 1d03h, GigabitEthernet0/0/0/1
+   i L2 192.0.2.24/30 [115/20] via 192.0.2.17, 1d03h, GigabitEthernet0/0/0/2
+
+Information about prefix-sid and label-operation from VyOS
+
+.. code-block:: none
+
+   vyos@P1-VyOS:~$ show isis route prefix-sid
+   Area VyOS:
+   IS-IS L2 IPv4 routing table:
+   
+    Prefix         Metric  Interface  Nexthop    SID  Label Op.
+    ----------------------------------------------------------------------
+    192.0.2.1/32   0       -          -          -    -
+    192.0.2.2/32   30      eth1       192.0.2.6  2    Swap(16002, 16002)
+    192.0.2.3/32   10      eth1       192.0.2.6  3    Pop(16003)
+    192.0.2.4/30   20      eth1       192.0.2.6  -    -
+    192.0.2.16/30  20      eth1       192.0.2.6  -    -
+    192.0.2.20/30  0       -          -          -    -
+    192.0.2.24/30  30      eth1       192.0.2.6  -    -
+
+    vyos@P2-VyOS:~$ show isis route prefix-sid
+    Area VyOS:
+    IS-IS L2 IPv4 routing table:
+    
+     Prefix         Metric  Interface  Nexthop     SID  Label Op.
+     -----------------------------------------------------------------------
+     192.0.2.1/32   30      eth2       192.0.2.18  1    Swap(16001, 16001)
+     192.0.2.2/32   0       -          -           -    -
+     192.0.2.3/32   10      eth2       192.0.2.18  3    Pop(16003)
+     192.0.2.4/30   20      eth2       192.0.2.18  -    -
+     192.0.2.16/30  20      eth2       192.0.2.18  -    -
+     192.0.2.20/30  30      eth2       192.0.2.18  -    -
+     192.0.2.24/30  0       -          -           -    -
+
+Ping between VyOS-P1 / VyOS-P2 to confirm reachability:
+
+.. code-block:: none
+
+   vyos@P1-VyOS:~$ ping 192.0.2.2 source-address 192.0.2.1
+   PING 192.0.2.2 (192.0.2.2) from 192.0.2.1 : 56(84) bytes of data.
+   64 bytes from 192.0.2.2: icmp_seq=1 ttl=63 time=3.47 ms
+   64 bytes from 192.0.2.2: icmp_seq=2 ttl=63 time=2.06 ms
+   64 bytes from 192.0.2.2: icmp_seq=3 ttl=63 time=3.90 ms
+   64 bytes from 192.0.2.2: icmp_seq=4 ttl=63 time=3.87 ms
+   ^C
+   --- 192.0.2.2 ping statistics ---
+   4 packets transmitted, 4 received, 0% packet loss, time 3004ms
+   rtt min/avg/max/mdev = 2.064/3.326/3.903/0.748 ms
+
+   vyos@P2-VyOS:~$ ping 192.0.2.1 source-address 192.0.2.2
+   PING 192.0.2.1 (192.0.2.1) from 192.0.2.2 : 56(84) bytes of data.
+   64 bytes from 192.0.2.1: icmp_seq=1 ttl=63 time=2.91 ms
+   64 bytes from 192.0.2.1: icmp_seq=2 ttl=63 time=3.23 ms
+   64 bytes from 192.0.2.1: icmp_seq=3 ttl=63 time=2.91 ms
+   64 bytes from 192.0.2.1: icmp_seq=4 ttl=63 time=2.85 ms
+   ^C
+   --- 192.0.2.1 ping statistics ---
+   4 packets transmitted, 4 received, 0% packet loss, time 3005ms
+   rtt min/avg/max/mdev = 2.846/2.972/3.231/0.151 ms
\ No newline at end of file
diff --git a/docs/configuration/protocols/segment-routing.rst b/docs/configuration/protocols/segment-routing.rst
index d8d0f116..5ee710e9 100644
--- a/docs/configuration/protocols/segment-routing.rst
+++ b/docs/configuration/protocols/segment-routing.rst
@@ -4,10 +4,10 @@
 Segment Routing
 ###############
 
-Segment Routing (SR) is a network architecture that is similar to 
-source-routing.In this architecture, the ingress router adds a list of segments,
-known as SIDs, to the packet as it enters the network. These segments represent
-different portions of the network path that the packet will take.
+Segment Routing (SR) is a network architecture that is similar to source-routing
+. In this architecture, the ingress router adds a list of segments, known as 
+SIDs, to the packet as it enters the network. These segments represent different 
+portions of the network path that the packet will take.
 
 The SR segments are portions of the network path taken by the packet, and are 
 called SIDs. At each node, the first SID of the list is read, executed as a 
@@ -28,7 +28,7 @@ which are running on most ISPs.
   MPLS labels are exchanged and populated by IGPs like IS-IS.Segment Routing
   as per RFC8667 for MPLS dataplane. It supports IPv4, IPv6 and ECMP and has
   been tested against Cisco & Juniper routers.however,this deployment is still
-  EXPERIMENTAL for FRR .
+  EXPERIMENTAL for FRR.
  
 
 IS-IS SR Configuration
@@ -50,21 +50,36 @@ devices, below configuration shows how to enable SR on IS-IS:
 
 
 
-.. cfgcmd:: set protocols isis segment-routing global-block <high-label-value 
-  | low-label-value> <label-value>
+.. cfgcmd::  set protocols isis segment-routing global-block high-label-value 
+  <label-value>
 
   Set the Segment Routing Global Block i.e. the label range used by MPLS to 
   store label in the MPLS FIB for Prefix SID. Note that the block size may 
   not exceed 65535.
 
-.. cfgcmd:: set protocols isis segment-routing local-block <high-label-value 
-  | low-label-value> <label-value>
+.. cfgcmd:: set protocols isis segment-routing global-block low-label-value 
+  <label-value>
+
+  Set the Segment Routing Global Block i.e. the low label range used by MPLS to 
+  store label in the MPLS FIB for Prefix SID. Note that the block size may 
+  not exceed 65535.
+ 
+.. cfgcmd:: set protocols isis segment-routing local-block high-label-value 
+  <label-value>
 
   Set the Segment Routing Local Block i.e. the label range used by MPLS to 
   store label in the MPLS FIB for Prefix SID. Note that the block size may 
   not exceed 65535.Segment Routing Local Block, The negative command always 
   unsets both.
 
+.. cfgcmd:: set protocols isis segment-routing local-block <low-label-value 
+  <label-value>
+
+  Set the Segment Routing Local Block i.e. the low label range used by MPLS to 
+  store label in the MPLS FIB for Prefix SID. Note that the block size may 
+  not exceed 65535.Segment Routing Local Block, The negative command always 
+  unsets both.
+
 .. cfgcmd:: set protocols isis segment-routing maximum-label-depth <1-16>
 
   Set the Maximum Stack Depth supported by the router. The value depend of
@@ -80,18 +95,23 @@ devices, below configuration shows how to enable SR on IS-IS:
 .. cfgcmd:: set protocols isis segment-routing prefix <address> index
    <no-php-flag | explicit-null| n-flag-clear>
 
-   prefix. The ‘no-php-flag’ means NO Penultimate Hop Popping that allows SR 
-   node to request to its neighbor to not pop the label. The ‘explicit-null’ 
-   flag allows SR node to request to its neighbor to send IP packet with the 
-   EXPLICIT-NULL label. The ‘n-flag-clear’ option can be used to explicitly
-   clear the Node flag that is set by default for Prefix-SIDs associated to 
-   loopback addresses. This option is necessary to configure Anycast-SIDs.
+   this option allows to configure prefix-sid on SR. The ‘no-php-flag’ means NO 
+   Penultimate Hop Popping that allows SR node to request to its neighbor to 
+   not pop the label. The ‘explicit-null’ flag allows SR node to request to its 
+   neighbor to send IP packet with the EXPLICIT-NULL label. The ‘n-flag-clear’ 
+   option can be used to explicitly clear the Node flag that is set by default 
+   for Prefix-SIDs associated to loopback addresses. This option is necessary 
+   to configure Anycast-SIDs.
 
 
 .. opcmd:: show isis segment-routing node
-
+ 
    Show detailed information about all learned Segment Routing Nodes
 
+.. opcmd:: show isis route prefix-sid
+
+   Show detailed information about prefix-sid and label learned
+
 .. note:: more information related IGP  - :ref:`routing-isis`
 
    
@@ -104,25 +124,40 @@ devices, below configuration shows how to enable SR on OSPF:
 
 .. cfgcmd:: set protocols ospf parameters opaque-lsa
 
-  Enable the Opaque-LSA capability (rfc2370),necessary to transport label 
+  Enable the Opaque-LSA capability (rfc2370), necessary to transport label 
   on IGP
 
 
-.. cfgcmd:: set protocols ospf segment-routing global-block <high-label-value 
-  | low-label-value> <label-value>
+.. cfgcmd:: set protocols ospf segment-routing global-block high-label-value 
+  <label-value>
 
   Set the Segment Routing Global Block i.e. the label range used by MPLS to 
   store label in the MPLS FIB for Prefix SID. Note that the block size may 
   not exceed 65535.
 
-.. cfgcmd:: set protocols ospf segment-routing local-block <high-label-value 
-  | low-label-value> <label-value>
+.. cfgcmd:: set protocols ospf segment-routing global-block low-label-value 
+  <label-value>
+
+  Set the Segment Routing Global Block i.e. the low label range used by MPLS to 
+  store label in the MPLS FIB for Prefix SID. Note that the block size may 
+  not exceed 65535.
+
+.. cfgcmd:: set protocols ospf segment-routing local-block high-label-value 
+  <label-value>
 
   Set the Segment Routing Local Block i.e. the label range used by MPLS to 
   store label in the MPLS FIB for Prefix SID. Note that the block size may 
   not exceed 65535.Segment Routing Local Block, The negative command always 
   unsets both.
 
+.. cfgcmd:: set protocols ospf segment-routing local-block <low-label-value 
+  <label-value>
+
+  Set the Segment Routing Local Block i.e. the low label range used by MPLS to 
+  store label in the MPLS FIB for Prefix SID. Note that the block size may 
+  not exceed 65535.Segment Routing Local Block, The negative command always 
+  unsets both.
+
 .. cfgcmd:: set protocols ospf segment-routing maximum-label-depth <1-16>
 
   Set the Maximum Stack Depth supported by the router. The value depend of
@@ -138,12 +173,13 @@ devices, below configuration shows how to enable SR on OSPF:
 .. cfgcmd:: set protocols ospf segment-routing prefix <address> index
    <no-php-flag | explicit-null| n-flag-clear>
 
-   prefix. The ‘no-php-flag’ means NO Penultimate Hop Popping that allows SR 
-   node to request to its neighbor to not pop the label. The ‘explicit-null’ 
-   flag allows SR node to request to its neighbor to send IP packet with the 
-   EXPLICIT-NULL label. The ‘n-flag-clear’ option can be used to explicitly
-   clear the Node flag that is set by default for Prefix-SIDs associated to 
-   loopback addresses. This option is necessary to configure Anycast-SIDs.
+   this option allows to configure prefix-sid on SR. The ‘no-php-flag’ means NO 
+   Penultimate Hop Popping that allows SR node to request to its neighbor to 
+   not pop the label. The ‘explicit-null’ flag allows SR node to request to its 
+   neighbor to send IP packet with the EXPLICIT-NULL label. The ‘n-flag-clear’ 
+   option can be used to explicitly clear the Node flag that is set by default 
+   for Prefix-SIDs associated to loopback addresses. This option is necessary 
+   to configure Anycast-SIDs.
 
 .. note:: more information related IGP  - :ref:`routing-ospf`
 
@@ -319,246 +355,3 @@ Here is the routing tables showing the MPLS segment routing label operations:
   O   10.1.1.2/32 [110/0] is directly connected, lo, weight 1, 00:03:51
   O   192.168.0.0/24 [110/1] is directly connected, eth0, weight 1, 00:03:51
 
-**************************
-Example with Cisco IOS-XR 
-**************************
-
-When utilizing VyOS in an environment with Cisco IOS-XR gear you can use this 
-blue print as an initial setup to get MPLS ISIS-SR working between those two 
-devices.The lab was build using :abbr:`EVE-NG (Emulated Virtual
-Environment NG)`.
-
-.. figure:: /_static/images/vyos-sr-isis.png
-   :alt: ISIS-SR network
-
-   ISIS-SR example network
-
-The below configuration is used as example where we keep focus on 
-VyOS-P1/VyOS-P2/XRv-P3 which we share the settings.
-
-
-Configuration
-=============
-
-VyOS-P1:
-========
-.. code-block:: none
-
-  set interfaces dummy dum0 address '192.0.2.1/32'
-  set interfaces ethernet eth1 address '192.0.2.5/30'
-  set interfaces ethernet eth1 mtu '8000'
-  set interfaces ethernet eth3 address '192.0.2.21/30'
-  set interfaces ethernet eth3 mtu '8000'
-  set protocols isis interface dum0 passive
-  set protocols isis interface eth1 network point-to-point
-  set protocols isis interface eth3 network point-to-point
-  set protocols isis level 'level-2'
-  set protocols isis log-adjacency-changes
-  set protocols isis metric-style 'wide'
-  set protocols isis net '49.0000.0000.0000.0001.00'
-  set protocols isis segment-routing maximum-label-depth '8'
-  set protocols isis segment-routing prefix 192.0.2.1/32 index value '1'
-  set protocols mpls interface 'eth1'
-  set protocols mpls interface 'eth3'
-  set system host-name 'P1-VyOS'
-
-XRv-P3:
-=======
-.. code-block:: none
-
-  hostname P3-VyOS
-  interface Loopback0
-   ipv4 address 192.0.2.3 255.255.255.255
-  !
-  interface GigabitEthernet0/0/0/1
-   mtu 8014
-   ipv4 address 192.0.2.6 255.255.255.252
-  !
-  interface GigabitEthernet0/0/0/2
-   mtu 8014
-   ipv4 address 192.0.2.18 255.255.255.252
-  !
-  router isis VyOS
-   is-type level-2-only
-   net 49.0000.0000.0000.0003.00
-   log adjacency changes
-   address-family ipv4 unicast
-    metric-style wide
-    segment-routing mpls
-   !
-   interface Loopback0
-    passive
-    address-family ipv4 unicast
-     prefix-sid index 3
-    !
-   !
-   interface GigabitEthernet0/0/0/1
-    point-to-point
-    address-family ipv4 unicast
-    !
-   !
-   interface GigabitEthernet0/0/0/2
-    point-to-point
-    address-family ipv4 unicast
-    !
-   !
-  !
-
-VyOS-P2:
-========
-.. code-block:: none
-  
-  set interfaces dummy dum0 address '192.0.2.2/32'
-  set interfaces ethernet eth2 address '192.0.2.17/30'
-  set interfaces ethernet eth2 mtu '8000'
-  set interfaces ethernet eth3 address '192.0.2.26/30'
-  set interfaces ethernet eth3 mtu '8000'
-  set protocols isis interface dum0 passive
-  set protocols isis interface eth2 network point-to-point
-  set protocols isis interface eth3 network point-to-point
-  set protocols isis level 'level-2'
-  set protocols isis log-adjacency-changes
-  set protocols isis metric-style 'wide'
-  set protocols isis net '49.0000.0000.0000.0002.00'
-  set protocols isis segment-routing maximum-label-depth '8'
-  set protocols isis segment-routing prefix 192.0.2.2/32 index value '2'
-  set protocols mpls interface 'eth2'
-  set protocols mpls interface 'eth3'
-  set system host-name 'P2-VyOS'
-
-This gives us MPLS segment routing enabled and labels forwarding :
-
-.. code-block:: none
-  
-   vyos@P1-VyOS:~$ show mpls table
-   Inbound Label  Type        Nexthop               Outbound Label
-   -----------------------------------------------------------------
-   15000          SR (IS-IS)  192.0.2.6             implicit-null
-   15001          SR (IS-IS)  192.0.2.22            implicit-null
-   15002          SR (IS-IS)  fe80::5200:ff:fe04:3  implicit-null
-   16002          SR (IS-IS)  192.0.2.6             16002
-   16003          SR (IS-IS)  192.0.2.6             implicit-null
-   16011          SR (IS-IS)  192.0.2.22            implicit-null
-  
-   vyos@P2-VyOS:~$ show mpls table
-   Inbound Label  Type        Nexthop     Outbound Label
-   -------------------------------------------------------
-   15000          SR (IS-IS)  192.0.2.18  implicit-null
-   16001          SR (IS-IS)  192.0.2.18  16001
-   16003          SR (IS-IS)  192.0.2.18  implicit-null
-   16011          SR (IS-IS)  192.0.2.18  16011
-
-   RP/0/0/CPU0:P3-VyOS#show mpls forwarding
-   Tue Mar 28 17:47:18.928 UTC
-   Local  Outgoing    Prefix             Outgoing     Next Hop        Bytes
-   Label  Label       or ID              Interface                    Switched
-   ------ ----------- ------------------ ------------ --------------- ------------
-   16001  Pop         SR Pfx (idx 1)     Gi0/0/0/1    192.0.2.5       0
-   16002  Pop         SR Pfx (idx 2)     Gi0/0/0/2    192.0.2.17      0
-   16011  16011       SR Pfx (idx 11)    Gi0/0/0/1    192.0.2.5       0
-   24000  Pop         SR Adj (idx 1)     Gi0/0/0/1    192.0.2.5       0
-   24001  Pop         SR Adj (idx 3)     Gi0/0/0/1    192.0.2.5       0
-   24002  Pop         SR Adj (idx 1)     Gi0/0/0/2    192.0.2.17      0
-   24003  Pop         SR Adj (idx 3)     Gi0/0/0/2    192.0.2.17      0
-
-
-VyOS is able to check MSD per devices: 
-
-.. code-block:: none
-
-   vyos@P1-VyOS:~$ show isis segment-routing node
-   Area VyOS:
-   IS-IS L1 SR-Nodes:
-  
-   IS-IS L2 SR-Nodes:
-  
-   System ID       SRGB           SRLB            Algorithm  MSD
-   ---------------------------------------------------------------
-   0000.0000.0001  16000 - 23999  15000 - 15999   SPF        8
-   0000.0000.0002  16000 - 23999  15000 - 15999   SPF        8
-   0000.0000.0003  16000 - 23999  0 - 4294967295  SPF        10
-   0000.0000.0011  16000 - 23999  15000 - 15999   SPF        8
-
-   vyos@P2-VyOS:~$ show isis segment-routing node
-   Area VyOS:
-    IS-IS L1 SR-Nodes:
-   
-    IS-IS L2 SR-Nodes:
-   
-    System ID       SRGB           SRLB            Algorithm  MSD
-    ---------------------------------------------------------------
-    0000.0000.0001  16000 - 23999  15000 - 15999   SPF        8
-    0000.0000.0002  16000 - 23999  15000 - 15999   SPF        8
-    0000.0000.0003  16000 - 23999  0 - 4294967295  SPF        10
-    0000.0000.0011  16000 - 23999  15000 - 15999   SPF        8
-
-Here is the routing tables showing the MPLS segment routing label operations:
-
-.. code-block:: none
-
-   vyos@P1-VyOS:~$ 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, F - PBR,
-          f - OpenFabric,
-          > - selected route, * - FIB route, q - queued, r - rejected, b - backup
-          t - trapped, o - offload failure
-   
-   I>* 192.0.2.2/32 [115/30] via 192.0.2.6, eth1, label 16002, weight 1, 1d03h18m
-   I>* 192.0.2.3/32 [115/10] via 192.0.2.6, eth1, label implicit-null, weight 1, 1d03h18m
-   I   192.0.2.4/30 [115/20] via 192.0.2.6, eth1 inactive, weight 1, 1d03h18m
-   I>* 192.0.2.11/32 [115/20] via 192.0.2.22, eth3, label implicit-null, weight 1, 1d02h47m
-   I>* 192.0.2.16/30 [115/20] via 192.0.2.6, eth1, weight 1, 1d03h18m
-   I   192.0.2.20/30 [115/20] via 192.0.2.22, eth3 inactive, weight 1, 1d02h48m
-   I>* 192.0.2.24/30 [115/30] via 192.0.2.6, eth1, weight 1, 1d03h18m
-   
-   
-   vyos@P2-VyOS:~$ 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, F - PBR,
-          f - OpenFabric,
-          > - selected route, * - FIB route, q - queued, r - rejected, b - backup
-          t - trapped, o - offload failure
-   
-   I>* 192.0.2.1/32 [115/30] via 192.0.2.18, eth2, label 16001, weight 1, 1d03h17m
-   I>* 192.0.2.3/32 [115/10] via 192.0.2.18, eth2, label implicit-null, weight 1, 1d03h17m
-   I>* 192.0.2.4/30 [115/20] via 192.0.2.18, eth2, weight 1, 1d03h17m
-   I>* 192.0.2.11/32 [115/40] via 192.0.2.18, eth2, label 16011, weight 1, 1d02h47m
-   I   192.0.2.16/30 [115/20] via 192.0.2.18, eth2 inactive, weight 1, 1d03h17m
-   I>* 192.0.2.20/30 [115/30] via 192.0.2.18, eth2, weight 1, 1d03h17m
-   
-   RP/0/0/CPU0:P3-VyOS#show route isis
-   Tue Mar 28 18:19:16.417 UTC
-   
-   i L2 192.0.2.1/32 [115/20] via 192.0.2.5, 1d03h, GigabitEthernet0/0/0/1
-   i L2 192.0.2.2/32 [115/20] via 192.0.2.17, 1d03h, GigabitEthernet0/0/0/2
-   i L2 192.0.2.11/32 [115/30] via 192.0.2.5, 1d02h, GigabitEthernet0/0/0/1
-   i L2 192.0.2.20/30 [115/20] via 192.0.2.5, 1d03h, GigabitEthernet0/0/0/1
-   i L2 192.0.2.24/30 [115/20] via 192.0.2.17, 1d03h, GigabitEthernet0/0/0/2
-
-Ping between VyOS-P1 / VyOS-P2 to confirm reachability:
-
-.. code-block:: none
-
-   vyos@P1-VyOS:~$ ping 192.0.2.2 source-address 192.0.2.1
-   PING 192.0.2.2 (192.0.2.2) from 192.0.2.1 : 56(84) bytes of data.
-   64 bytes from 192.0.2.2: icmp_seq=1 ttl=63 time=3.47 ms
-   64 bytes from 192.0.2.2: icmp_seq=2 ttl=63 time=2.06 ms
-   64 bytes from 192.0.2.2: icmp_seq=3 ttl=63 time=3.90 ms
-   64 bytes from 192.0.2.2: icmp_seq=4 ttl=63 time=3.87 ms
-   ^C
-   --- 192.0.2.2 ping statistics ---
-   4 packets transmitted, 4 received, 0% packet loss, time 3004ms
-   rtt min/avg/max/mdev = 2.064/3.326/3.903/0.748 ms
-
-   vyos@P2-VyOS:~$ ping 192.0.2.1 source-address 192.0.2.2
-   PING 192.0.2.1 (192.0.2.1) from 192.0.2.2 : 56(84) bytes of data.
-   64 bytes from 192.0.2.1: icmp_seq=1 ttl=63 time=2.91 ms
-   64 bytes from 192.0.2.1: icmp_seq=2 ttl=63 time=3.23 ms
-   64 bytes from 192.0.2.1: icmp_seq=3 ttl=63 time=2.91 ms
-   64 bytes from 192.0.2.1: icmp_seq=4 ttl=63 time=2.85 ms
-   ^C
-   --- 192.0.2.1 ping statistics ---
-   4 packets transmitted, 4 received, 0% packet loss, time 3005ms
-   rtt min/avg/max/mdev = 2.846/2.972/3.231/0.151 ms
\ No newline at end of file