IEEE 802.1ag CFM
802.1ag is a set of protocols that allows an operator to detect, locate and verify faults for an Ethernet service. The Connectivity Check protocol allows the operator to monitor the services continuously through data-path keep-alives. Once a failure is detected, the Loopback and Linktrace protocols are used on-demand to diagnose the failure further. The CFM protocols defined in 802.1ag are useful for multipoint as well as point-to-point Ethernet services.
Scalability of 802.1ag is accomplished via the use of maintenance domains. A maintenance domain is defined by the network operator as a network area with its own management and administration requirements. Maintenance domains can be defined in hierarchical order to distinguish between different types of network users (e.g. carrier-of-carriers).
802.1ag tool includes three protocols that complement each other and enable network monitoring:
Continuity Check – This protocol works at a maintenance domain and sends periodic messages from one maintenance endpoint to the other, checking availability of connections.
Linktrace – This on-demand protocol allows the operator to trace the path towards a particular MAC address destination. It is a form of MAC layer traceroute.
Loopback – Another on-demand protocol, loopback allows the operator to isolate a fault to a location between a pair of maintenance points.
use scenario in my Metro Ethernet Network:
the element :Alcatel 7750 ,Mrv 912
the customer service is point-to-point Epipe 1G
we config in the cpe mrv QinQ .the customer have connect it's cisco router to two service porvidor
with Ethetrchannel with lacp but when he try check the redundant by pull out one of the ethernet port
it is was to long time that the lacp was detect it and put it in suspend (2 minute).
so our solution it is to config 802.1ag and link-reflection between the interface that connect to the customer and when one of the interface down or the service are down the 802.1ag are detect and the link-reflection are shutdown the port and this fast the redundant for the customer:
the config:
OS906-1(config-ethoam-Lev1:MAiD#1)# w t
Building configuration...
Current configuration:
! version 2_1_4B
!
line vty
no exec-timeout global
!
no port lt-learning 1,3-4
port trunk t1 3-4
link-reflection uplink t1 downlink 1 srv 1 dmn 1 rmep 2 !
port tag-outbound-mode q-in-q 1,t1 100
!
interface vlan vif100
tag 100
ports 1,t1
!
ethernet oam domain 1
service 1
vlans 100
remote-meps 2
mep 1 port 1
mep 1 primary-vlan 100
mep 1 activate
mep 1 ccm-activate
ethernet oam enable
-----------------------------------
switch-2
OS906C-2(config)# w t
Building configuration...
Current configuration:
! version 2_1_4B
!
line vty
no exec-timeout global
!
no port lt-learning 1,5-6
!
port trunk t1 5-6
!
link-reflection uplink t1 downlink 1 srv 1 dmn 1 rmep 1 !
port tag-outbound-mode q-in-q 1,t1 100
!
interface vlan vif100
tag 100
ports 1,t1
!
ethernet oam domain 1
service 1
vlans 100
remote-meps 1
mep 2 port 1
mep 2 primary-vlan 100
mep 2 activate
mep 2 ccm-activate
!
ethernet oam enable
No comments:
Post a Comment