Understand SRv6 Static Segment Identifier
The Segment Routing for IPv6 (SRv6) Static Segment Identifier (SID) Configuration feature enhances network traffic management by allowing static allocation of Segment Identifiers (SIDs) for micro and classic locators. This functionality is pivotal for environments where traditional Interior Gateway Protocols (IGP) like IS-IS are not utilized, providing an alternative path computation method. By enabling the advertisement of these static SIDs over BGP, you can facilitate segment routing traffic engineering, improving both efficiency and flexibility. You gain the capability to configure micro node, adjacency, and classic END and END-X SIDs, with support for primary and backup interfaces and various flavors. Additionally, SRv6 Operations, Administration, and Maintenance (OAM) support, including ping and traceroute functionalities, bolsters operational and troubleshooting capabilities. With several CLI commands available for configuration, this feature ensures effective use of static SIDs while managing potential conflicts with dynamic routing protocols.
Benefits of Segment Routing for IPv6 Static Segment Identifier Configuration
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Enhance network traffic management by allowing the use of static SIDs in environments lacking traditional IGP routing protocols, ensuring effective path computation and traffic engineering.
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Facilitate segment routing traffic engineering by enabling static SID advertisement over BGP, which improves network efficiency and flexibility.
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Provide robust operational support through SRv6 OAM features like ping and traceroute, aiding in effective network troubleshooting and maintenance.
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Support configuration for both primary and backup interfaces, ensuring network resilience and continuity in case of interface failures.
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Allow integration of static SIDs with dynamic tunnels for Layer 3 VPN services, supporting service resolution and maintaining network service quality.
Configuration Overview
The SRv6 Static SID Configuration feature allows you to define static SIDs in your network, providing precise control over traffic management without the need for traditional IGP protocols like IS-IS. By configuring these static SIDs, you can advertise them over BGP, facilitating segment routing traffic engineering that optimizes path computation and network efficiency. The feature supports various SID types, including micro node and adjacency SIDs as well as classic END and END-X SIDs, offering flexibility in managing both primary and backup interfaces.
SRv6 manager supports micro-sid locators under the [edit routing-options
source-packet-routing srv6] hierarchy. This supports allocation of static and
dynamic node SIDs and adjacency SIDs with SRv6 by applications. The flavors configured for
the locator is inherited by the micro SIDs configured under it. This configuration supports
flavors such as penultimate segment pop (PSP), ultimate segment decapsulation (USD), and
ultimate segment pop (USP), which are essential for tailoring traffic flows according to
specific network requirements. The following is the configuration hierarchy:
[edit routing-options] user@host# set source-packet-routing srv6 locator locator-name micro-sid flavor ? Possible completions: + apply-groups Groups from which to inherit configuration data + apply-groups-except Don't inherit configuration data from these groups none No flavor psp Penultimate segment pop of the SRH usd Ultimate segment decapsulation usp Ultimate segment pop of the SRH
You can allocate node SIDs for micro-SID locators using the following configuration. If IS-IS is configured, it installs remote micro node SIDs in the inet6.3 table. Remote micro node SIDs allocated by SRv6 manager are advertised through the BGP export policy and is installed in inet6.0 table.
[edit routing-options] user@host# set source-packet-routing srv6 locator locator-name micro-sid node-sid
You can allocate adjacency SIDs for micro-SID locators. Static SRv6 routes for adjacency SIDs is updated on any interface events. When a primary or backup interface goes down, the corresponding next hop is removed from the route and is added back when the interface becomes available. For a static micro adjacency SID, you can configure up to eight interfaces as backup. Here is the configuration to allocate adjacency SIDs for micro-SID locators:
[edit routing-options] user@host# set source-packet-routing srv6 locator locator-name micro-sid adjacency-sid
The following is a sample configuration of adjacency SIDs for micro-SID:
[edit routing-options] user@host# set source-packet-routing srv6 locator loc1 2001:db8::/48 micro-sid adjacency-sid 0xf850 interface ge-0/0/0.0 Possible completions: <[Enter]> Execute this command next-hop Next hop for adjacency sid backup Marks the interface as protection for adjacency SID | Pipe through a command
The backup statement is used to indicate that the interface is going to act as a protection for the adjacency SID. This allows to form a non-weighted ECMP for the adjacency SID and in the event of primary interface going down, the PFE switches the traffic to backup.
The next-hop statement is required in the case of broadcast links where the next hop address must be explicitly mentioned for proper forwarding.
SRv6 manager supports allocation of static and dynamic END SIDs and END-X SIDs for classic locators. You can now allocate static END SIDs and END-X SIDs with SRv6 as the application. Flavors for classic SIDs can be configured as follows:
[edit routing-options] user@host# set source-packet-routing srv6 locator loc1 2001:db8::/48 end-sid 5000::1 Possible completions: <[Enter]> Execute this command > flavor Configure end-SID flavor | Pipe through a command
You can allocate END SIDs for classic locators along with flavors PSP, USD and USP. If IS-IS is configured, it installs remote END SIDs in the inet6.3 table. Remote END SIDs allocated by SRv6 manager is advertised through BGP export policy and is installed in inet6.0 table.
You can allocate END-X SIDs for classic locators along with flavors PSP, USD and USP. Static SRv6 routes for END-X SIDs is updated on any interface events. Like micro-adjacency SIDs, when the primary or backup interface goes down, the corresponding next hop is removed from the route and is added back once the interface becomes available. Like micro adjacency SIDs, END-X SIDs supports backup interfaces and next-hop. For a static END-X SID, up to eight interfaces can be configured as backup.
The following is a sample configuration of END-X SIDs:
[edit routing-options] user@host# set source-packet-routing srv6 locator loc1 2001:db8::/48 end-x-sid 0xf850 interface ge-0/0/0.0 Possible completions: <[Enter]> Execute this command next-hop Next hop for END-X SID backup Marks the interface as protection for END-X SID | Pipe through a command
It is possible for both IS-IS and SRv6 manager to configure static SIDs for the same locator. You need to consider the following while configuring both IS-IS and static SIDs:
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When both IS-IS and SRv6 manager configures the same static micro adjacency SID or classic adjacency SID or classic node SID, a commit check fails due to duplicate allocation.
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Micro node SID can be configured by both IS-IS and SRv6 manager without any commit check failures. In this case, the IS-IS' SID route will have more preference over the SRv6 route.
- It is possible for IS-IS to configure non-zero algo SIDs but the SRv6 manager only installs zero algo SIDs in the inet6.0 table even though algorithm is configured for the locator. IS-IS installs the non-zero algo SIDs in the inet6color.0 table while using the same locator as SRv6 manager.
Moreover, the SRv6 OAM capabilities, which include ping and traceroute support, enhance network operation by offering robust troubleshooting tools. These features allow for monitoring the status and paths of static SIDs, providing visibility into segment routing operations. The SRv6 static SID configuration also supports integration with dynamic tunnels for Layer 3 VPN services, ensuring service resolution over statically configured SIDs. This integration is crucial for maintaining network service quality and resilience, particularly in environments where multi-hop BGP is not supported, thus ensuring continuity and stability in network operations.