- MPLS Traffic Engineering and Enhancements
- MPLS Traffic Engineering-Configurable Path Calculation Metric for Tunnels
- MPLS Traffic Engineering-Scalability Enhancements
- MPLS Traffic Engineering-LSP Attributes
- MPLS Traffic Engineering-AutoTunnel Mesh Groups
- MPLS Traffic Engineering Verbatim Path Support
- MPLS Traffic Engineering RSVP Hello State Timer
- MPLS Traffic Engineering Forwarding Adjacency
- MPLS Traffic Engineering Class-based Tunnel Selection
- MPLS Traffic Engineering Interarea Tunnels
- MPLS Traffic Engineering-Automatic Bandwidth Adjustment for TE Tunnels
- MPLS Traffic Engineering Tunnel Source
- Finding Feature Information
- Prerequisites for MPLS Traffic Engineering--AutoTunnel Mesh Groups
- Restrictions for MPLS Traffic Engineering--AutoTunnel Mesh Groups
- Information About MPLS Traffic Engineering--AutoTunnel Mesh Groups
- How to Configure MPLS Traffic Engineering--AutoTunnel Mesh Groups
- Configuration Examples for MPLS Traffic Engineering--Autotunnel Mesh Groups
- Additional References
- Feature Information for MPLS Traffic Engineering--Autotunnel Mesh Groups
- Glossary
MPLS Traffic Engineering--AutoTunnel Mesh Groups
The MPLS Traffic Engineering--Autotunnel Mesh Groups feature allows a network administrator to configure traffic engineering (TE) label switched paths (LSPs) by using a few command-line interface (CLI) commands.
In a network topology where edge TE label switch routers (LSRs) are connected by core LSRs, the MPLS Traffic Engineering--Autotunnel Mesh Groups feature automatically constructs a mesh of TE LSPs among the provider edge (PE) routers.
- Finding Feature Information
- Prerequisites for MPLS Traffic Engineering--AutoTunnel Mesh Groups
- Restrictions for MPLS Traffic Engineering--AutoTunnel Mesh Groups
- Information About MPLS Traffic Engineering--AutoTunnel Mesh Groups
- How to Configure MPLS Traffic Engineering--AutoTunnel Mesh Groups
- Configuration Examples for MPLS Traffic Engineering--Autotunnel Mesh Groups
- Additional References
- Feature Information for MPLS Traffic Engineering--Autotunnel Mesh Groups
- Glossary
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the Feature Information Table at the end of this document.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Prerequisites for MPLS Traffic Engineering--AutoTunnel Mesh Groups
- Be knowledgeable about MPLS TE. See the Additional References.
- Decide how you will set up autotunnels (that is, identify the tunnel commands that you will include in the template interface).
- Identify a block of addresses that you will reserve for mesh tunnel interfaces.
Restrictions for MPLS Traffic Engineering--AutoTunnel Mesh Groups
- Mesh groups do not support interarea tunnels because the destinations of those tunnels do not exist in the local area TE database.
- You cannot configure a static route to route traffic over autotunnel mesh group TE tunnels. You should use only the autoroute for tunnel selection.
- Intermediate System-to-System (IS-IS) does not support Interior Gateway Protocol (IGP) distribution of mesh group information. For IS-IS, only Access Control Lists (ACLs) can be used.
Information About MPLS Traffic Engineering--AutoTunnel Mesh Groups
- AutoTunnel Mesh Groups Description and Benefits
- Access Lists for Mesh Tunnel Interfaces
- AutoTunnel Template Interfaces
- OSPF Flooding of Mesh Group Information
AutoTunnel Mesh Groups Description and Benefits
An autotunnel mesh group (referred to as a mesh group) is a set of connections between edge LSRs in a network. There are two types of mesh groups:
- Full--All the edge LSRs are connected. Each PE router has a tunnel to each of the other PE routers.
- Partial--Some of the edge LSRs are not connected to each other by tunnels.
In a network topology where edge TE LSRs are connected by core LSRs, the MPLS Traffic Engineering--Autotunnel Mesh Groups feature automatically constructs a mesh of TE LSPs among the PE routers.
Initially, you must configure each existing TE LSR to be a member of the mesh by using a minimal set of configuration commands. When the network grows (that is, when one or more TE LSRs are added to the network as PE routers), you do not need to reconfigure the existing TE LSR members of that mesh.
Mesh groups have the following benefits:
- Minimize the initial configuration of the network. You configure one template interface per mesh, and it propagates to all mesh tunnel interfaces, as needed.
- Minimize future configurations resulting from network growth. The feature eliminates the need to reconfigure each existing TE LSR to establish a full mesh of TE LSPs whenever a new PE router is added to the network.
- Enable existing routers to configure TE LSPs to new PE routers.
- Enable the construction of a mesh of TE LSPs among the PE routers automatically.
Access Lists for Mesh Tunnel Interfaces
The access list determines the destination addresses for the mesh tunnel interfaces. It is useful if you preallocate a block of related IP addresses. You can use that block of addresses to control the PE routers to which a full or partial mesh of TE tunnel LSPs is established. The access list allows matches for only the addresses that are learned and stored in the TE topology database.
For example, you can create an access list that matches all 10.1.1.1 IP addresses. You configure a template with the access list, then the template creates mesh tunnel interfaces to destinations within the TE topology database that match destinations in that access list.
Whenever the TE topology database is updated (for example, when a new TE LSR is inserted into the Interior Gateway Protocol (IGP), the destination address is stored in the TE topology database of each router in the IGP. At each update, the Mesh Group feature compares the destination address contained in the database to IP addresses in the access list associated with all template interfaces. If there is a match, the Mesh Group feature establishes a mesh tunnel interface to the tunnel destination IP address.
AutoTunnel Template Interfaces
An autotunnel template interface is a logical entity; that is, it is a configuration for a tunnel interface that is not tied to specific tunnel interfaces. It can be applied dynamically, when needed.
Mesh tunnel interfaces are tunnel interfaces that are created, configured dynamically (for example, by the applying [or cloning] of a template interface), used, and then freed when they are no longer needed.
A mesh tunnel interface obtains its configuration information from a template, except for the tunnel's destination address, which it obtains from the TE topology database that matches an access list or from the IGP mesh group advertisement.
The template interface allows you to enter commands once per mesh group. These commands specify how mesh tunnel interfaces are created. Each time a new router is added to the network, a new mesh tunnel interface is created. The configuration of the interface is duplicated from the template. Each mesh tunnel interface has the same path constraints and other parameters configured on the template interface. Only the tunnel destination address is different.
OSPF Flooding of Mesh Group Information
For OSPF to advertise or flood mesh group information, you need to configure a mesh group in OSPF and add that mesh group to an autotemplate interface. When the configuration is complete, OSPF advertises the mesh group IDs to all LSRs. MPLS TE LSPs automatically connect the edge LSRs in each mesh group. For configuration information, see the Configuring IGP Flooding for Autotunnel Mesh Groups.
OSPF can advertise mesh group IDs for an OSPF area. OSPF is the only IGP supported in the Cisco IOS 12.0(29)S, 12.2(33)SRA, 12.2(33)SXH, and 12.4(20)T releases of the MPLS Traffic Engineering--Autotunnel Mesh Groups feature.
How to Configure MPLS Traffic Engineering--AutoTunnel Mesh Groups
- Configuring a Mesh of TE Tunnel LSPs
- Specifying the Range of Mesh Tunnel Interface Numbers
- Displaying Configuration Information About Tunnels
- Monitoring the Autotunnel Mesh Network
- Configuring IGP Flooding for Autotunnel Mesh Groups
Configuring a Mesh of TE Tunnel LSPs
Perform the following tasks on each PE router in your network to configure a mesh of TE tunnel LSPs:
Note |
You can perform these tasks in any order. |
- Enabling Autotunnel Mesh Groups Globally
- Creating an Access List Using a Name
- Creating an Autotunnel Template Interface
Enabling Autotunnel Mesh Groups Globally
Perform this task on all PE routers in your network that you want to be part of an autotunnel mesh group.
DETAILED STEPS
Creating an Access List Using a Name
The access list determines the destination addresses for the mesh tunnel interfaces. You can use an access list to control the PE routers to which a full or partial mesh of TE tunnel LSPs is established. The access list allows matches for only the addresses that are learned and stored in the TE topology database.
DETAILED STEPS
Creating an Autotunnel Template Interface
Creating an autotunnel template interface helps minimize the initial configuration of the network. You configure one template interface per mesh, which propagates to all mesh tunnel interfaces, as needed.
Note |
You can use the following commands to create a minimal configuration. |
DETAILED STEPS
Specifying the Range of Mesh Tunnel Interface Numbers
DETAILED STEPS
Displaying Configuration Information About Tunnels
DETAILED STEPS
Step 1 | enable Use this command to enable privileged EXEC mode. Enter your password if prompted. For example: Example:
Router> enable
Router#
|
Step 2 | show running interface auto-template num Use this command to display interface configuration information for a tunnel interface. For example: Example:
Router# show running interface auto-template 1
interface auto-template1
ip unnumbered Loopback0
no ip directed-broadcast
no keepalive
tunnel destination access-list 1
tunnel mode mpls traffic-eng
tunnel mpls traffic-eng autoroute announce
tunnel mpls traffic-eng path-option 1 dynamic
This output shows that autotunnel template interface auto-template1 uses an access list (access-list 1) to determine the destination addresses for the mesh tunnel interfaces. |
Step 3 | show interface tunnel num configuration Use this command to display the configuration of the mesh tunnel interface. For example: Example:
Router# show interface tunnel 5 configuration
interface tunnel 5
ip unnumbered Loopback0
no ip directed-broadcast
no keepalive
tunnel destination access-list 1
tunnel mode mpls traffic-eng
tunnel mpls traffic-eng autoroute announce
tunnel mpls traffic-eng path-option 1 dynamic
|
Step 4 | exit Use this command to exit to user EXEC mode. For example: Example:
Router# exit
Router>
|
Monitoring the Autotunnel Mesh Network
DETAILED STEPS
Step 1 | enable Use this command to enable privileged EXEC mode. Enter your password if prompted. For example: Example:
Router> enable
Router#
|
Step 2 | show mpls traffic-eng tunnels property auto-tunnel mesh [brief] Use this command to monitor mesh tunnel interfaces. This command restricts the output of the show mpls traffic-eng tunnels command to display only mesh tunnel interfaces. For example: Example:
Router# show mpls traffic-eng tunnels property auto-tunnel mesh brief
Signalling Summary:
LSP Tunnels Process: running
RSVP Process: running
Forwarding: enabled
Periodic reoptimization: every 3600 seconds, next in 491 seconds
Periodic FRR Promotion: Not Running
Periodic auto-bw collection: disabled
TUNNEL NAME DESTINATION UP IF DOWN IF
STATE/PROT
router_t64336 10.2.2.2 - Se2/0
up/up
router_t64337 10.3.3.3 - Se2/0
up/up
Displayed 2 (of 2) heads, 0 (of 0) midpoints, 0 (of 0) tails
|
Step 3 | show mpls traffic-eng auto-tunnel mesh Use this command to display the cloned mesh tunnel interfaces of each autotemplate interface and the current range of mesh tunnel interface numbers. For example: Example:
Router# show mpls traffic-eng auto-tunnel mesh
Auto-Template1:
Using access-list 1 to clone the following tunnel interfaces:
Destination Interface
----------- ---------
10.2.2.2 Tunnel64336
10.3.3.3 Tunnel64337
Mesh tunnel interface numbers: min 64336 max 65337
|
Step 4 | exit Use this command to exit to user EXEC mode. For example: Example:
Router# exit
Router>
|
Troubleshooting Tips
You can configure mesh tunnel interfaces directly. However, you cannot delete them manually, and manual configuration is not permanent. The configuration is overwritten when the template changes or the mesh tunnel interface is deleted and re-created. If you attempt to manually delete a mesh tunnel interface, an error message appears.
You can enter the show mpls traffic-eng tunnels destination address command to display information about tunnels that are destined for a specified IP address.
Enter the show mpls traffic-eng tunnels property auto-tunnel mesh command to display information about mesh tunnel interfaces.
Configuring IGP Flooding for Autotunnel Mesh Groups
Perform the following task to configure IGP flooding for autotunnel mesh groups. Use this task to configure an OSPF-based discovery for identifying mesh group members and advertising the mesh group IDs to all LSRs.
DETAILED STEPS
Configuration Examples for MPLS Traffic Engineering--Autotunnel Mesh Groups
- Configuring a Mesh of TE Tunnel LSPs Examples
- Specifying the Range of Mesh Tunnel Interface Numbers Example
- Configuring IGP Flooding for Autotunnel Mesh Groups Example
Configuring a Mesh of TE Tunnel LSPs Examples
This section contains the following configuration examples for configuring a mesh of TE tunnel LSP:
- Enabling Autotunnel Mesh Groups Globally Example
- Creating an Access List Using a Name Example
- Creating an AutoTunnel Template Interface Example
Enabling Autotunnel Mesh Groups Globally Example
The following example shows how to enable autotunnel mesh groups globally:
configure terminal ! mpls traffic-eng auto-tunnel mesh end
Creating an Access List Using a Name Example
The following examples shows how to create an access list using a name to determine the destination addresses for the mesh tunnel interfaces:
configure terminal ! ip access-list standard a1 permit 10.0.0.0 0.255.255.255 end
In this example, any IP address in the TE topology database that matches access list a1 causes the creation of a mesh tunnel interface with that destination address.
Creating an AutoTunnel Template Interface Example
This example shows how to create an AutoTunnel template template interface. In the following example, an AutoTunnel template is created and configured with a typical set of TE commands. The mesh group created from the template consists of mesh tunnel interfaces with destination addresses that match access list a1.
Note |
The following example shows a typical configuration. |
configure terminal ! interface auto-template 1 ip unnumbered Loopback0 tunnel mode mpls tunnel mpls traffic-eng autoroute announce tunnel mpls traffic-eng priority 1 1 tunnel mpls traffic-eng auto-bw tunnel mpls traffic-eng path-option 1 dynamic tunnel destination access-list a1 end
Specifying the Range of Mesh Tunnel Interface Numbers Example
In the following example, the lowest mesh tunnel interface number can be 1000, and the highest mesh tunnel interface number can be 2000:
configure terminal ! mpls traffic-eng auto-tunnel mesh tunnel-num min 1000 max 2000 end
Configuring IGP Flooding for Autotunnel Mesh Groups Example
In the following example, OSPF is configured to advertise the router membership in mesh group 10:
configure terminal ! mpls traffic-eng auto-tunnel mesh router ospf 100 mpls traffic-eng mesh-group 10 loopback 0 area 100 exit ! interface auto-template 1 tunnel destination mesh-group 10 end
Additional References
Related Documents
Related Topic |
Document Title |
---|---|
MPLS traffic engineering command descriptions |
Cisco IOS Multiprotocol Label Switching Command Reference |
Standards
Standard |
Title |
---|---|
No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature. |
-- |
MIBs
MIB |
MIBs Link |
---|---|
No new or modified MIBs are supported by this feature, and support for existing MIBs has not been modified by this feature. |
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: |
RFCs
RFC |
Title |
---|---|
No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature. |
-- |
Technical Assistance
Description |
Link |
---|---|
The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies. To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds. Access to most tools on the Cisco Support website requires a Cisco.com user ID and password. |
Feature Information for MPLS Traffic Engineering--Autotunnel Mesh Groups
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 1 | Feature Information for MPLS Traffic Engineering--Autotunnel Mesh Groups |
Feature Name |
Releases |
Feature Information |
---|---|---|
MPLS Traffic Engineering--Autotunnel Mesh Groups |
12.0(27)S 12.0(29)S 12.2(33)SRA 12.2(33)SXH 12.4(20)T 12.2(33)SRE |
The MPLS Traffic Engineering--AutoTunnel Mesh Groups feature allows a network administrator to configure TE LSPs. In Cisco IOS Release 12.2(27)S, this feature was introduced. In Cisco IOS Release 12.0(29)S, this feature was updated to include Interior Gateway Protocol (IGP) flooding of autotunnel mesh groups. In Cisco IOS Release 12.2(33)SRA, this feature was integrated. In Cisco IOS Release 12.2(33)SXH, support was added. In Cisco IOS Release 12.4(20)T, this feature was integrated. In Cisco IOS Release 12.2(33)SRE, this feature was integrated. A router with autotunnel mesh groups can be configured with stateful switchover (SSO) redundancy. |
MPLS TE--Autotunnel/Auotmesh SSO Coexistence |
XE 3.5S |
In Cisco IOS XE Release 3.5S, this feature was integrated. |
Glossary
CE router --customer edge router. A router that is part of a customer's network and interfaces to a provider edge (PE) router.
customer network --A network that is under the control of an end customer. Private addresses can be used in a customer network. Customer networks are logically isolated from each other and from the service provider's network.
edge router --A router at the edge of the network that receives and transmits packets. It can define the boundaries of the Multiprotocol Label Switching (MPLS) network.
headend --The label switch router (LSR) where a tunnel originates. The tunnel's "head" or tunnel interface resides at this LSR as well.
label --A short, fixed-length data construct that tells switching nodes how to forward data (packets).
label switched path (LSP) tunnel --A configured connection between two routers in which label switching is used to carry the packets.
LSP --label switched path. A path that a labeled packet follows over several hops, starting at an ingress LSR and ending at an egress LSR.
LSR --label switch router. A Layer 3 router that forwards a packet based on the value of a label encapsulated in the packet.
mesh group --A set of label switch routers (LSRs) that are members of a full or partial network of traffic engineering (TE) label switched paths (LSPs).
P router --provider core router.
PE router --provider edge router. A router at the edge of the service provider's network that interfaces to customer edge (CE) routers.
router --A network layer device that uses one or more metrics to determine the optimal path along which network traffic should be forwarded. Routers forward packets from one network to another based on network layer information.
tailend --The downstream, receive end of a tunnel.
traffic engineering --The techniques and processes used to cause routed traffic to travel through the network on a path other than the one that would have been chosen if standard routing methods had been used.
tunnel --A secure communication path between two peers, such as two routers. A traffic engineering tunnel is a label switched tunnel that is used for traffic engineering. Such a tunnel is set up through means other than normal Layer 3 routing.
Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this URL: www.cisco.com/go/trademarks. Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1110R)
Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.