Configuring Auto TE FRR
Pre-configuration Tasks
Auto TE FRR is a local protection technique and is used to protect a CR-LSP against link faults and node faults. Auto TE FRR does not need to be configured manually.
- Configure a dynamic MPLS TE or DS-TE tunnel. For details, see Configuring a Dynamic MPLS TE Tunnel or Configuring a Dynamic DS-TE Tunnel.
- Enable MPLS, MPLS TE and RSVP-TE in the system view and interface view of each node along a bypass tunnel.
- Enable CSPF on a PLR.
To implement fast switching within milliseconds, configure BFD association. For details about BFD, see Configuring Association Between the BFD Session and the Interface Status in Huawei AR Series Access Routers Configuration Guide - Reliability. When associating a BFD session with an interface, ensure that the interface is protected by the bypass tunnel.
Configuration Procedure
Except that configuring a TE FRR scanning timer, changing the PSB and RSB timeout multiplier, configuring auto bypass tunnel re-optimization, and configuring interworking with other vendors are optional, other configurations are mandatory.
- Enabling Auto TE FRR
- Enabling the TE FRR and Configuring the Auto Bypass Tunnel Attributes
- (Optional) Configuring a TE FRR Scanning Timer
- (Optional) Changing the PSB and RSB Timeout Multiplier
- (Optional) Configuring Auto Bypass Tunnel Re-Optimization
- (Optional) Configuring Interworking with a Non-Huawei Device
- Verifying the Auto TE FRR Configuration
Enabling Auto TE FRR
Context
Before configuring auto TE FRR, enable auto TE FRR globally on the PLR. To implement link protection, enable link protection on an interface.
Perform the following configurations on the PLR.
Procedure
- Run system-view
The system view is displayed.
- Run mpls
The MPLS view is displayed.
- Run mpls te auto-frr
Auto TE FRR is enabled globally.
After auto TE FRR is enabled globally, link protection is enabled on all interfaces enabled with MPLS TE. - (Optional) Configure MPLS TE Auto FRR in the interface
view.
- Run mpls te auto-frr { link | node | default }
Auto TE FRR is enabled on the outbound interface on the ingress node of the primary tunnel.
To implement link protection, specify link. If link is not specified, the system provides only node protection.
By default, after auto TE FRR is enabled globally, all the MPLS TE interfaces are automatically configured with the mpls te auto-frr default command. To disable auto TE FRR on some interfaces, run the mpls te auto-frr block command on these interfaces. Then, these interfaces no longer have auto TE FRR capability even if auto TE FRR is enabled or is to be re-enabled globally.
After mpls te auto-frr is used in the MPLS view, the mpls te auto-frr default or mpls te auto-frr node command used on an interface protects only nodes. When the topology does not meet the requirement to set up an automatic bypass tunnel for node protection, the penultimate hop (but not other hops) on the primary tunnel attempts to set up an automatic bypass tunnel for link protection.
- Run mpls te auto-frr { link | node | default }
Enabling the TE FRR and Configuring the Auto Bypass Tunnel Attributes
Context
After TE Auto FRR is enabled, the system automatically sets up a bypass tunnel.
Perform the following configurations on the ingress node of the primary MPLS TE tunnel.
Procedure
- Run system-view
The system view is displayed.
- Run interface tunnel interface-number
The tunnel interface view of the primary tunnel is displayed.
- Run mpls te fast-reroute [ bandwidth ]
The TE FRR is enabled.
To guarantee the tunnel bandwidth, you must specify the parameter bandwidth.
- (Optional) Run mpls te bypass-attributes [ bandwidth bandwidth ] [ priority setup-priority [ hold-priority ] ]
The attributes of the bypass tunnel are configured.
The bypass tunnel attributes can be configured only after the mpls te fast-reroute bandwidth command is run on the primary tunnel.
- The bandwidth of the bypass tunnel cannot be greater than the bandwidth of the primary tunnel.
- When the attributes of the automatic bypass tunnel are not configured, by default, the bandwidth of the automatic bypass tunnel is the same as the bandwidth of the primary tunnel.
- The setup priority of the bypass tunnel cannot be higher than the holding priority. Both priorities cannot be higher than the priority of the primary tunnel.
When the bandwidth of the primary tunnel is changed or the FRR is disabled, the attributes of the bypass tunnel are cleared automatically.
On one TE tunnel interface, the bandwidth of the bypass tunnel cannot be configured together with the multi-CT.
- Run mpls te commit
The current configuration of the tunnel is committed.
(Optional) Configuring a TE FRR Scanning Timer
Context
A TE FRR-enabled device periodically refreshes the binding between a bypass CR-LSP and a primary LSP at a specified interval. The PLR searches for the optimal TE bypass CR-LSP and binds it to a primary CR-LSP. A TE FRR scanning timer is set to determine the interval at which the binding between a bypass CR-LSP and a primary CR-LSP is refreshed.
Perform the following configurations on the PLR.
Procedure
- Run system-view
The system view is displayed.
- Run mpls
The MPLS view is displayed.
- Run mpls te timer fast-reroute [ weight ]
Set the interval at which the binding between a bypass CR-LSP and a primary CR-LSP is refreshed.
By default, the time weight used to calculate the interval is 300. And the actual interval at which the binding between a bypass CR-LSP and a primary LSP is refreshed depends on device performance and the maximum number of LSPs that can be established on the device.
(Optional) Changing the PSB and RSB Timeout Multiplier
Context
To help allow TE FRR to operate during the RSVP GR process, the timeout multiplier of the Path State Block (PSB) and Reservation State Block (RSB) can be set. The setting prevents the situation where information in PSBs and RSBs is dropped due to a timeout before the GR processes are complete for a large number of CR-LSPs.
Perform the following configurations on the PLR.
Procedure
- Run system-view
The system view is displayed.
- Run mpls
The MPLS view is displayed.
- Run mpls rsvp-te keep-multiplier keep-multiplier-number
The PSB and RSB timeout multiplier is set.
The default timeout multiplier is 3.
Setting the timeout multiplier to 5 or greater is recommended for a network where a large number of CR-LSPs are established and RSVP GR is configured.
(Optional) Configuring Auto Bypass Tunnel Re-Optimization
Context
Network changes often cause the changes in optimal paths. Auto Bypass tunnel re-optimization allows paths to be recalculated at certain intervals for an auto bypass tunnel. If an optimal path to the same destination is found due to some reasons, such as the changes in the cost, a new auto bypass tunnel will be set up over this optimal path. In this manner, network resources are optimized.
Perform the following configurations on the PLR.
Procedure
- Run system-view
The system view is displayed.
- Run mpls
The MPLS view is displayed.
- Run mpls te auto-frr reoptimization [ frequency interval ]
Auto bypass tunnel re-optimization is enabled.
By default, auto bypass tunnel re-optimization is disabled. If re-optimization is enabled, the default interval at which auto bypass tunnel re-optimization is performed is 3600 seconds.
- (Optional) Immediately re-optimize the tunnels on which
automatic re-optimization is enabled.
(Optional) Configuring Interworking with a Non-Huawei Device
Verifying the Auto TE FRR Configuration
Procedure
- Run the display mpls te tunnel verbose command to check binding information about the primary tunnel and the auto bypass tunnel.
- Run the display mpls lsp attribute bypass-inuse { inuse | not-exists | exists-not-used } command to check information about the attribute of a specified bypass LSP.
- Run the display mpls lsp attribute bypass-tunnel tunnel-name command to check information about the attribute of a bypass tunnel.
- Run the display mpls te tunnel-interface [ tunnel interface-number | auto-bypass-tunnel [ tunnel-name ] ] command to check detailed information about the tunnel interface of a specified primary or bypass tunnel.
- Run the display mpls te tunnel path [ [ [ tunnel-name ] tunnel-name ] [ lsp-id ingress-lsr-id session-id lsp-id ] | fast-reroute { local-protection-available | local-protection-inuse } | lsr-role { ingress | transit | egress } ] command to check information about paths of a specified primary or bypass tunnel.
- Run the display mpls rsvp-te statistics fast-reroute command to check TE FRR statistics.
- Run the display mpls stale-interface [ interface-index ] [ verbose ] command to check the information about MPLS interfaces in the Stale state.
- Enabling Auto TE FRR
- Enabling the TE FRR and Configuring the Auto Bypass Tunnel Attributes
- (Optional) Configuring a TE FRR Scanning Timer
- (Optional) Changing the PSB and RSB Timeout Multiplier
- (Optional) Configuring Auto Bypass Tunnel Re-Optimization
- (Optional) Configuring Interworking with a Non-Huawei Device
- Verifying the Auto TE FRR Configuration