22.1.7 Common operation specifications

<Structure of this section>

(1) Operation on blocked ports

The following tables describe the behavior of each type of CFM functionality for a blocked port.

Table 22-7 When the Up MEP is in the block state
Functionality	Operation
CC	Sends and receives a CCM and sets Blocked as the status of the port from which the CCM was sent.
Loopback	The l2ping operation command cannot be executed. Responds to loopback messages sent to the local switch.
Linktrace	The l2traceroute operation command cannot be executed. Responds to link trace messages. Sets Blocked for the status of the egress port from which a response linktrace message is expected.

Table 22-8 When the Down MEP is in the block state
Functionality	Operation
CC	CCM is not sent.
Loopback	The l2ping operation command cannot be executed. Does not respond to loopback messages sent to the local switch.
Linktrace	The l2traceroute operation command cannot be executed. Does not respond to linktrace messages.

Table 22-9 When the MIP is in the block state
Functionality	Operation
CC	Does not transmit CCMs.
Loopback	Does not respond to a loopback message received from the line side and sent to the local switch. Responds to a loopback message received from the forwarding and sent to the local switch. Does not transmit loopback messages.
Linktrace	Does not respond to a linktrace message received from the line side Responds to a linktrace message received from the forwarding side. Sets Blocked for the status of the egress port from which a response linktrace message is expected. Does not transmit linktrace messages

Table 22-10 When the port other than MEP and MIP is in the block state
Functionality	Operation
CC	Does not transmit CCMs.
Loopback	Does not transmit loopback messages.
Linktrace	Does not transmit linktrace messages

(2) About Settings in VLAN Tunneling Configuration

When using the CFM functionality in a VLAN tunneling network, divide the domain for the VLAN tunneling network into an inside part and an outside part so that you can manage the resulting networks separately. Note, however, that some parts of the CFM functionality have restrictions on use depending on the locations where the domain is configured. The following table describes the restrictions on functionality according to where the domains are configured.

Table 22-11: Restrictions on the use of functionality by domain configuration
Where a domain is configured	Functionality
Where a domain is configured	CC	Loopback	Linktrace
Inside the VLAN tunneling network and outside the VLAN tunneling network	Can be used	Can be used	Can be used inside the VLAN tunneling network Cannot be used outside the VLAN tunneling network via the VLAN tunnel
Inside the VLAN tunneling network only	Can be used	Can be used	Can be used
Outside the VLAN tunneling network only	Can be used	Can be used	Can be used

(a) When using CFM inside VLAN tunneling network and outside VLAN tunneling network

The following figure shows an example of using the CFM functionality inside and outside the VLAN tunneling network.

Figure 22-27 Example of using CFM in the VLAN tunneling network and outside the VLAN tunneling network

In domain level 1 inside the VLAN tunneling network, you can configure MPs anywhere on the VLAN tunneling network. At domain level 6 outside the VLAN tunneling network, you can configure MPs only on switches outside the VLAN tunneling network. You cannot configure MPs for domain level 6 inside the VLAN tunneling network. Management inside the VLAN tunneling network is performed at domain level 1.

In addition, in domain level 6 outside the VLAN tunneling network, you cannot use the linktrace functionality through a VLAN tunnel.

(b) When using CFM only within VLAN tunneling network

The following figure shows an example of using the CFM functionality only inside the VLAN tunneling network.

Figure 22-28 Example of Using CFM Only in VLAN Tunneling Networks

In domain level 1 inside the VLAN tunneling network, you can configure MPs anywhere on the VLAN tunneling network. You can use the CFM functionality in the domain.

(c) When using CFM only outside VLAN tunneling network

The following figure shows an example of using the CFM functionality only outside the VLAN tunneling network.

Figure 22-29 Example of using CFM only outside the VLAN tunneling network

At domain level 6 outside the VLAN tunneling network, you can configure MPs only on switches outside the VLAN tunneling network. You cannot configure MPs for domain level 6 inside the VLAN tunneling network. You can use the CFM functionality in the domain.