Resource Reservation Protocol (RSVP) auto bypass is a subset of the Facility Backup feature, designed to enhance fast-reroute protection. The facility backup feature operates by establishing bypass tunnels for protected sessions at each PLR node, serving as a local safeguard for sessions on every Point of Local Repair (PLR). Configuring bypass tunnels manually on each PLR, particularly in larger topologies, presented challenges in configuration management. The RSVP auto bypass functionality ensures to dynamically create bypass tunnels when feature enabled in PLR nodes and the sessions come up in PLR requesting facility backup protection.

The RSVP auto bypass operates in conjunction with manual bypass tunnels, and if both manual and auto bypass offer the same level of protection as requested, the manual bypass takes precedence. Auto bypass tunnels, which do not serve any session, have a finite lifetime and are deleted if they remain unused.

RSVP auto bypass contributes to a more automated, efficient, and manageable facility backup protection mechanism in RSVP-enabled networks.

Ensure the following prerequisites are met before configuring RSVP Auto Bypass functionality:

Enable ISIS to facilitate dynamic routing on all nodes within the network. Define ISIS router instances to match loopback IP addresses and add network segments to ISIS areas for proper route distribution. Set up neighbor relationships using loopback IP addresses, ensuring efficient route advertisement and convergence for optimal network performance.

Enable Resource Reservation Protocol (RSVP) on all nodes to optimize traffic routing and quality of service. RSVP reserves network resources along specified paths to enhance network performance and reliability.

Establish a trunk on edge routers participating in label-switching using defined path.

This section shows the configuration of the various nodes within the topology to set up a RSVP-Auto bypass tunnels.

The sample topology includes Edge Nodes (PE1, PE2) and core Nodes (P1, P3 and P4). As per sample configurations, Primary path is defined via PE1-P1-P3-PE2 using strict hops and auto bypass tunnel creation is formed on PE1.

Before configuring RSVP-Auto bypass tunnles, meet all Prerequisites for the following nodes:

Auto bypass feature helps in automatically forming bypass tunnels and protecting the facility backup protection requested tunnels.

Bypass name will have a character B or D. BL for Link protection and BN is for Node protection.

 

 

 

 

 

 

 

Shutdown interface between PE1-P1, so that primary path goes Down and backup in use.

 

 

 

 

 

 

 

Manual bypass and auto bypass coexist and when manual bypass already providing perfect protection, then manual bypass preferred over auto bypass. auto bypass won't be triggered.

Auto bypass is created when Manual bypass is provided with perfect protection as link

Manual bypass and auto bypass coexist and when manual bypass already providing perfect protection, auto bypass session goes down when manual bypass exists.

Verify all RSVP sessions information: The output shows only manual bypass session information when Manual bypass and auto bypass coexist and when manual bypass already providing perfect protection.

 

 

 

Manual bypass for link protection is UP and auto bypass for node protection is UP and running.

 

 

 

The RSVP auto bypass introduces the following configuration commands within the Facility Backup commands.

Use this command to enter a new mode of auto-bypass to configure auto bypass specific commands and enable auto bypass feature.

Use the no parameter to auto bypass configurations. When configuration removed at global level, all auto bypass configuration will be removed and all dynamically created bypass tunnels will be deleted.

None

Disabled

Router mode

Introduced in OcNOS version 6.5.1.

This example is for configuring auto bypass:

Use this command to enable or disable auto bypass functionality. When this functionality is enabled, sessions requesting facility backup protection will attempt creation of bypass tunnels dynamically, if no satisfying bypass protection is available. If topology supports the formation of dynamically created bypass session, then the sessions will be protected by dynamically created bypass tunnels.

 

When manual bypass created, which satisfies protection requirement similar to auto bypass tunnels, then manual bypass tunnel gets preference over auto bypass tunnels. However, if auto bypass tunnels provide better protection (based on session request) than manual bypass, then auto bypass tunnels considered for protection over manual bypass tunnels.

 

Use the disable parameter to disable the auto bypass functionality. When this functionality is disabled, all dynamically created bypass tunnels will be deleted.

None

Disabled

Auto bypass mode

Introduced in OcNOS version 6.5.1.

This example is for enabling the auto bypass:

This example is for disabling the auto bypass:

Use the no parameter to reset auto bypass inactivity timer to default value.

None

Auto bypass mode

Introduced in OcNOS version 6.5.1.

This example is for setting the inactivity timer to 5 minutes:

Use the no parameter to reset auto bypass attributes of matching type to default values.

The initial configuration for best-effort auto bypass attributes is not set, and the internal entities have their default settings.

Auto bypass mode

Introduced in OcNOS version 6.5.1.

This example is for configuring auto bypass attributes:

This example is to reset auto bypass attributes of matching type to default values:

Use the no parameter to reset the attribute to default value which is capability type node.

The value for protection capability is node.

Auto bypass attribute mode

Introduced in OcNOS version 6.5.1.

Example for setting up the protection capability attribute to link:

Example to reset the protection capability attribute to default value:

Use the no parameter to remove bandwidth attribute and auto bypass sessions will not request any bandwidth constraint to form LSP.

None

Auto bypass attribute mode

Introduced in OcNOS version 6.5.1.

Example for setting up the bandwidth attribute to 100g:

Example to reset the bandwidth attribute to default value:

Use the no parameter to reset setup priority attribute to default value.

None

Auto bypass attribute mode

Introduced in OcNOS version 6.5.0.

Example for setting up the setup priority attribute to 5.

Example to reset the setup priority attribute to default value.

Use the no parameter to reset hold priority attribute to default value.

None

Auto bypass attribute mode

Introduced in OcNOS version 6.5.1.

Example for setting up the hold priority attribute to 2:

Example to reset the hold priority attribute to default value:

Use the no parameter to reset hop limit attribute to default value.

None

Auto bypass attribute mode

Introduced in OcNOS version 6.5.1.

Example for setting up the hop limit attribute to 5:

Example to reset the hop limit attribute to default value:

Use the no parameter to disable re-optimization for auto bypass.

None

The auto bypass re-optimization is disabled.

Auto bypass attribute mode

Introduced in OcNOS version 6.5.1.

Example for enabling the re-optimization attribute:

Example for disabling the re-optimization attribute:

Use the no parameter to remove the exclude address constraint.

 

Auto bypass will only have an implicit exclude address, which is the immediate link or node of the protected session. No additional exclude address constraints are applied.

Auto bypass attribute mode

Introduced in OcNOS version 6.5.1.

Example for configuring exclude address attribute to link 10.1.1.2:

Example for configuring exclude address attribute to node 2.2.2.2:

Example to remove the exclude address constraint from link 10.1.1.2:

None

Exec and Privileged exec mode

Introduced in OcNOS version 6.5.1.

Example for viewing RSVP router ID table:

None

Exec and Privileged exec mode

Introduced in OcNOS version 6.5.1.

Example for viewing SRLG group:

show rsvp srlg-group parameters output details

The following provides definitions for key terms or abbreviations and their meanings used throughout this document: