From 129b232ea135019489ddf64e5287c04930b2a318 Mon Sep 17 00:00:00 2001 From: Jonathan Voss Date: Fri, 10 Apr 2026 06:53:11 -0500 Subject: isis: T6978: add IS-IS SRv6 configuration (#1760) --- docs/configuration/protocols/isis.rst | 147 ++++++++++++++++++++++++++++++++++ 1 file changed, 147 insertions(+) (limited to 'docs') diff --git a/docs/configuration/protocols/isis.rst b/docs/configuration/protocols/isis.rst index 0fb0e9e0..75634800 100644 --- a/docs/configuration/protocols/isis.rst +++ b/docs/configuration/protocols/isis.rst @@ -355,6 +355,69 @@ Loop Free Alternate (LFA) This command will limit LFA backup computation up to the specified prefix priority. +Segment Routing over IPv6 (SRv6) +------------------------- + +.. cfgcmd:: set protocols isis segment-routing srv6 interface + + The :ref:`dummy interface` used + to install SRv6 SIDs into the Linux data plane. The interface must exist and + must be present when configuring IS-IS with + SRv6. + +.. cfgcmd:: set protocols isis segment-routing srv6 locator + + Specifies the SRv6 locator to use for IS-IS. IS-IS automatically allocates + prefix and adjacency SIDs, creates local SID entries and advertises them + into the IGP domain. + +.. cfgcmd:: set protocols isis segment-routing srv6 node-msd max-end-d <0-255> + + The Maximum End D MSD Type specifies the maximum number of SIDs present in an + SRH when performing decapsulation. As specified in :rfc:`8986`, the permitted + SID types include, but are not limited to, End.DX6, End.DT4, End.DT46, End + with USD, and End.X with USD. + + If the advertised value is zero or no value is advertised, then the router + cannot apply any behavior that results in decapsulation and forwarding of the + inner packet if the outer IPv6 header contains an SRH. + + Reference: :rfc:`9352` + +.. cfgcmd:: set protocols isis segment-routing srv6 node-msd max-end-pop <0-255> + + The Maximum End Pop MSD Type signals the maximum number of SIDs in the SRH to + which the router can apply "Penultimate Segment Pop (PSP) of the SRH" or + "Ultimate Segment Pop (USP) of the SRH" behavior, as defined in "Flavors" + (Section 4.16 of :rfc:`8986`). + + If the advertised value is zero or no value is advertised, then the router + cannot apply PSP or USP flavors. + + Reference: :rfc:`9352` + +.. cfgcmd:: set protocols isis segment-routing srv6 node-msd max-h-encaps <0-255> + + The Maximum H.Encaps MSD Type signals the maximum number of SIDs that can be + added to the segment list of an SRH as part of the "H.Encaps" behavior, as + defined in :rfc:`8986`. + + If the advertised value is zero or no value is advertised, then the headend + can apply an SR Policy that only contains one segment without inserting any + SRH header. A non-zero SRH Max H.encaps MSD indicates that the headend can + insert an SRH up to the advertised number of SIDs. + + Reference: :rfc:`9352` + +.. cfgcmd:: set protocols isis segment-routing srv6 node-msd max-segs-left <0-255> + + The Maximum Segments Left MSD Type signals the maximum value of the + "Segments Left" field (:rfc:`8754`) in the SRH of a received packet before + applying the Endpoint behavior associated with a SID. + + If no value is advertised, the supported value is 0. + + Reference: :rfc:`9352` ******** Examples @@ -598,3 +661,87 @@ Here is the routing tables showing the MPLS segment routing label operations: I 192.0.2.0/24 [115/20] via 192.0.2.1, eth1 inactive, weight 1, 00:07:46 I>* 192.168.255.255/32 [115/20] via 192.0.2.1, eth1, label IPv4 Explicit Null, weight 1, 00:03:43 + +Enable IS-IS with Segment Routing over IPv6 (Experimental) +========================================================== + +**Node 1:** + +.. code-block:: none + + set interfaces dummy dum6 description "SRv6 IS-IS" + set interfaces ethernet eth1 address '192.0.2.1/24' + set interfaces loopback lo address '192.168.255.255/32' + + set protocols segment-routing srv6 locator MAIN prefix 2001:db8:1::/64 + set protocols segment-routing interface eth1 + + set protocols isis interface eth1 + set protocols isis interface lo + set protocols isis net '49.0001.1921.6825.5255.00' + set protocols isis segment-routing srv6 locator MAIN + set protocols isis segment-routing srv6 interface dum6 + +**Node 2:** + +.. code-block:: none + + set interfaces dummy dum6 description "SRv6 IS-IS" + set interfaces ethernet eth1 address '192.0.2.2/24' + set interfaces loopback lo address '192.168.255.254/32' + + set protocols segment-routing srv6 locator MAIN prefix 2001:db8:2::/64 + set protocols segment-routing interface eth1 + + set protocols isis interface eth1 + set protocols isis interface lo + set protocols isis net '49.0001.1921.6825.5254.00' + set protocols isis segment-routing srv6 locator MAIN + set protocols isis segment-routing srv6 interface dum6 + +Enable IS-IS with Segment Routing over IPv6 (uSID) (Experimental) +================================================================= + +**Node 1:** + +.. code-block:: none + + set interfaces dummy dum6 description "SRv6 IS-IS" + set interfaces ethernet eth1 address '192.0.2.1/24' + set interfaces loopback lo address '192.168.255.255/32' + + set protocols segment-routing interface eth1 + set protocols segment-routing srv6 locator MAIN prefix 2001:db8:1::/48 + set protocols segment-routing srv6 locator MAIN behavior-usid + set protocols segment-routing srv6 locator MAIN block-len 32 + set protocols segment-routing srv6 locator MAIN format usid-f3216 + set protocols segment-routing srv6 locator MAIN func-bits 16 + set protocols segment-routing srv6 locator MAIN node-len 16 + + set protocols isis interface eth1 + set protocols isis interface lo + set protocols isis net '49.0001.1921.6825.5255.00' + set protocols isis segment-routing srv6 interface dum6 + set protocols isis segment-routing srv6 locator MAIN + +**Node 2:** + +.. code-block:: none + + set interfaces dummy dum6 description "SRv6 IS-IS" + set interfaces ethernet eth1 address '192.0.2.2/24' + set interfaces loopback lo address '192.168.255.254/32' + + set protocols segment-routing interface eth1 + set protocols segment-routing srv6 locator MAIN prefix 2001:db8:2::/48 + set protocols segment-routing srv6 locator MAIN behavior-usid + set protocols segment-routing srv6 locator MAIN block-len 32 + set protocols segment-routing srv6 locator MAIN format usid-f3216 + set protocols segment-routing srv6 locator MAIN func-bits 16 + set protocols segment-routing srv6 locator MAIN node-len 16 + + set protocols isis interface eth1 + set protocols isis interface lo + set protocols isis net '49.0001.1921.6825.5254.00' + set protocols isis segment-routing srv6 interface dum6 + set protocols isis segment-routing srv6 locator MAIN -- cgit v1.2.3