Junos® OS Ethernet Interfaces Configuration ... - Juniper Networks

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OS 12.3 Ethernet Interfaces Configuration Guide
Configuring MAC Flush Message Processing in CET Mode
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In carrier Ethernet transport (CET) mode, MX Series routers are used as provider edge
(PE) routers, and Nokia Siemens Networks A2200 Carrier Ethernet Switches (referred
to as E-domain devices) that run standard-based protocols are used in the access side.
On the MX Series routers, VPLS pseudowires are configured dynamically through label
distribution protocol (LDP). On the E-domain devices, topology changes are detected
through connectivity fault management (CFM) sessions running between the E-domain
devices and the MX Series PE routers. The MX Series PE routers can bring the carrier
Ethernet interface down if there is CFM connectivity loss. This triggers a local MAC flush
as well as a targeted label distribution protocol (T-LDP) MAC flush notification that gets
sent towards the remote MX Series PEs to trigger MAC flush on them.
In CET inter-op mode, MX Series routers need to interoperate with the Nokia Siemens
Networks Ax100 Carrier Ethernet access devices (referred to as A-domain devices) that
run legacy protocols. Nokia Siemens Networks A4100 and A8100 devices act as an
intermediate between the MX Series PE routers and A-domain devices. These intermediate
devices perform interworking function (IWF) procedures so that operations administration
management (OAM) sessions can be run between MX Series routers and A-domain
devices. There are no VPLS pseudowires between the MX Series PE routers and the Nokia
Siemens Networks A4100 and A8100 intermediate devices, so there is no LDP protocol
running between the PE routers to send topology change notifications. In order to
communicate topology changes, MX Series routers can trigger a MAC flush and propagate
it in the core. MX Series routers can use action profiles based upon the connection
protection type length value (TLV) event. The action profile brings down the carrier edge
logical interface in MX Series PE routers, which will trigger a local MAC flush and also
propagate the topology change to the core using LDP notification.
For VPLS there is no end-to-end connectivity monitored. The access rings are
independently monitored by running CFM down multiple end points (MEPs) on the
working and protection paths for each of the services between the E-domain devices
and the MX Series PE routers, and between the A-domain devices and the MX Series PE
routers the IWF hosted by the Nokia Siemens Networks A-4100 devices. When there is
a connectivity failure on the working path, the Nokia Siemens Networks Ax200 devices
perform a switchover to the protection path, triggering a topology change notification
(in the form of TLVs carried in CCM) to be sent on the active path.
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