How To Configure Ethernet Oam; Configuring Ethernet Link Oam - Cisco NCS 5500 Series Configuration Manual

Configuring Ethernet OAM
This figure shows an example of a network with multiple VLANS using CFM.
Figure 7: Service Provider Network With Multiple VLANs and CFM
This figure shows a provider's access network, where the S-VLAN tag is used as the service delimiter. PE1
faces the customer, and PE2 is at the edge of the access network facing the core. N:1 bundling is used, so the
interface encapsulation matches a range of C-VLAN tags. This could potentially be the full range, resulting
in all:1 bundling. There is also a use case where only a single C-VLAN is matched, but the S-VLAN is
nevertheless used as the service delimiter—this is more in keeping with the IEEE model, but limits the provider
to 4094 services.
CFM is used in this network with a MEP at each end of the access network, and MIPs on the boxes within
the network (if it is native Ethernet). In the normal case, CFM frames are sent by the up MEP on PE1 with
two VLAN tags, matching the customer data traffic. This means that at the core interfaces and at the MEP on
PE2, the CFM frames are forwarded as if they were customer data traffic, since these interfaces match only
on the S-VLAN tag. So, the CFM frames sent by the MEP on PE1 are not seen by any of the other MPs.
Flexible VLAN tagging changes the encapsulation for CFM frames that are sent and received at Up MEPs.
Flexible VLAN tagging allows the frames to be sent from the MEP on PE1 with just the S-VLAN tag that
represents the provider service. If this is done, the core interfaces will treat the frames as CFM frames and
they will be seen by the MIPs and by the MEP on PE2. Likewise, the MEP on PE1 should handle received
frames with only one tag, as this is what it will receive from the MEP on PE2.
To ensure that CFM packets from Up MEPs are routed to the appropriate paths successfully, tags may be set
to a specific number in a domain service, using the tags command. Currently, tags can only be set to one (1).

How to Configure Ethernet OAM

This section provides these configuration procedures:

Configuring Ethernet Link OAM

Custom EOAM settings can be configured and shared on multiple interfaces by creating an EOAM profile in
Ethernet configuration mode and then attaching the profile to individual interfaces. The profile configuration
does not take effect until the profile is attached to an interface. After an EOAM profile is attached to an
interface, individual EOAM features can be configured separately on the interface to override the profile
settings when desired.
This section describes how to configure an EOAM profile and attach it to an interface in these procedures:
Interface and Hardware Component Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.1.x

How to Configure Ethernet OAM

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