REP Access
Gateway
Resilient Ethernet
Protocol (REP) is a Cisco proprietary protocol that provides an alternative to
the Spanning Tree Protocol (STP). REP provides fast reconvergence and traffic
recovery when a link in a ring fails. Fast reconvergence is achieved by
notifying all nodes in the ring with a control message that activates the
redundant path to the core network.
The REP Access
Gateway Enhancements feature allows fast failure detection notifications
between devices configured with REP access gateway (REP-AG), by enabling
communication between Connectivity Fault Manager (CFM) and REP.
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and 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.
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Restrictions for
REP Access Gateway Enhancements
-
EFD is only supported on physical ports and services; it is not
supported on VLAN sub interfaces.
-
The CCM interval for CMF service on which EFD is supported is
limited by the platform capabilities.
-
The EFD feature is only supported on Down MEPs.
-
EFD is not supported on trunk services.
-
EFD is not supported for both G-8032 and REP at the same time.
-
Only one MEP on a given interface or EFP may be configured for EFD.
You cannot have MEPs operating at multiple CFM levels on the same interface.
Information About
REP Access Gateway Enhancements
REP Access Gateway
Enhancements
In a network where a REP and non-REP devices are connected and when a
link failure occurs, a Non-REP device network (access gateway) directly
connected to REP network sends failure notification, so that REP network can
reroute the traffic to an alternate route. But, access devices supporting REP
Edge No-Neighbor (REP ENN) only support one interface configured as a REP Edge
No-Neighbor port, resulting in an unsupported architecture with the REP Access
Gateway (REP AG) device.
Figure 1. REP Access Gateway
Fast failure detection in a REP-AG configured device can be achieved by
enabling communication between Connectivity Fault Manager (CFM) and REP. CFM on
the edge ports can notify REP if any failure is detected on the monitored
links, allowing the appropriate re-convergence actions to be taken.
The mechanism for the communication is for REP to register as an
Ethernet Fault Detection (EFD) client, so that any CFM defects above a
configurable threshold triggers a notification to REP.
How to Configure
REP Access Gateway Enhancements
Configuring REP
Access Gateway Enhancements
Perform this task
to configure EFD messages to REP devices.
SUMMARY STEPS1.
enable
2.
configure terminal
3.
ethernet cfm global
4.
link-protection enable
5.
link-protection
group
management
vlan
vlan-id
6.
link-protection
group
group-number
pccm
vlan
vlan-id
7.
ethernet
cfm
domain
domain-namelevel
level-id
[
direction
outward ]
8.
service
{
ma-name |
ma-number |vlan-id
vlan-id |vpn-id
vpn-id }
[port
|
vlan
vlan-id [direction
down ]
]
9.
continuity-check
10.
continuity-check
[
interval
time |
loss-threshold
threshold |
static
rmep ]
11.
efd
notify
rep
12.
end
DETAILED STEPS | Command or Action | Purpose |
---|
Step 1 | enable
Example:
Device> enable
|
Enables
privileged EXEC mode.
|
Step 2 | configure terminal
Example:
Device# configure terminal
|
Enters global
configuration mode.
|
Step 3 | ethernet cfm global
Example:
Device(config)# ethernet cfm global
|
Enables
Ethernet CFM globally.
|
Step 4 | link-protection enable
Example:
Device(config)# link-protection enable
|
Enables link
protection globally on the router.
|
Step 5 | link-protection
group
management
vlan
vlan-id
Example:
Device(config)# link-protection group management vlan 51
|
Defines the
management VLAN used for link protection.
|
Step 6 | link-protection
group
group-number
pccm
vlan
vlan-id
Example:
Device(config)# link-protection group 2 pccm vlan 16
|
Specifies an
ODU-to-ODU continuity check message (P-CCM) VLAN.
|
Step 7 | ethernet
cfm
domain
domain-namelevel
level-id
[
direction
outward ]
Example:
Device(config)# ethernet cfm domain REP_domain level 4
|
Configures
the CFM domain for ODU 1 and enters Ethernet CFM configuration mode.
|
Step 8 | service
{
ma-name |
ma-number |vlan-id
vlan-id |vpn-id
vpn-id }
[port
|
vlan
vlan-id [direction
down ]
]
Example:
Device(config-ecfm)# service rep_service evc rep-evc vlan 1001 direction down
|
Defines a
maintenance association for ODU 1 and enters Ethernet CFM service instance
configuration mode.
|
Step 9 | continuity-check
Example:
Device(config-ecfm)# continuity-check
|
Enables CCM message transmission.
|
Step 10 | continuity-check
[
interval
time |
loss-threshold
threshold |
static
rmep ]
Example:
Device(config)# Device(config-ecfm-srv)# continuity-check interval 3.3ms
|
Configures
the time period between CCM message transmissions
|
Step 11 | efd
notify
rep
Example:
Device(config-ecfm-srv)# efd notify rep
|
Enables EFD
notifications to REP devices.
|
Step 12 | end
Example:
Device(config-ecfm-srv)# end
|
Returns to
user EXEC mode.
|
Verifying REP
Access Gateway Enhancements
Perform this
optional task to verify the status of interface monitored for EFD.
SUMMARY STEPS1.
enable
2.
show
interface
number
rep detail
DETAILED STEPS
Step 1
|
enable
Enables
privileged EXEC mode. Enter your password if prompted.
Example:
|
Step 2
|
show
interface
number
rep detail
Use this
command to verify that EFD is enabled for REP devices:
Example:
device# show interface ethenet 0/0/1 rep detail
GigabitEthernet1/7 REP enabled
Segment-id: 10 (Primary Edge No-Neighbor)
PortID: 0007001AE3DC2680
Preferred flag: Yes
EFD Status: Enabled
EFD State: Fault/Clear
Operational Link Status: NO_NEIGHBOR
Current Key: 0007001AE3DC26806BD6
Port Role: Alternate
Blocked VLAN: 30-40
Admin-vlan: 500
|
Configuration
Examples For REP Access Gateway Enhancements
Example
Configuring REP Access Gateway Enhancements
This example
shows how to configure EFD messages for REP devices.
Device> enable
Device# configure terminal
Device(config)# ethernet cfm global
Device(config)# link-protection enable
Device(config)# link-protection group management vlan 51
Device(config)# link-protection group 2 pccm vlan 16
Device(config)# ethernet cfm domain REP_domain level 4
Device(config-ecfm)# service rep_service evc rep-evc vlan 1001 direction down
Device(config-ecfm-srv)# continuity-check
Device(config-ecfm-srv)# continuity-check interval 3.3ms
Device(config-ecfm-srv)# efd notify rep
Device(config-ecfm-srv)# end
Additional References for REP Access Gateway
Standards and RFCs
Standard/RFC
|
Title
|
Standard
|
Title
|
MIBs
MIB
|
MIBs Link
|
|
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
http://www.cisco.com/go/mibs
|
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.
|
http://www.cisco.com/cisco/web/support/index.html
|
Feature
Information for REP Access Gateway Enhancement
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
Resilient Ethernet Protocol
Feature
Name
|
Releases
|
Feature
Information
|
REP Access
Gateway Enhancements
|
Cisco IOS
XE Release 3.13
|
The REP Access Gateway Enhancements feature allows fast
failure detection notifications between devices configured with REP access
gateway (REP-AG), by enabling communication between Connectivity Fault Manager
(CFM) and REP.
The following commands were introduced by this feature:
efd
notify
rep
.
|