Check Bridge Forwarding

The CFM service can be activated on the ports of a bridge, allowing the bridge to make forwarding decisions depending on the content of the datagrams received on the CFM port. The following scenarios show how, with different configurations, the bridge does or does not forward CFM datagrams.

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Non CFM Bridge Forward CCM

Description

In this scenario, the CFM service is not configured on any port of the bridge br0 of DUT0. So, the bridge should forward any CFM datagram received on its ports.

Scenario

Step 1: Set the following configuration in DUT0:

set interfaces bridge br0 address 10.0.0.1/24
set interfaces ethernet eth0 bridge-group bridge br0

Step 2: Set the following configuration in DUT1:

set interfaces ethernet eth0 address 10.0.0.2/24

Step 3: Run command traffic dump monitor interface br0 filter "ether[12:2] == 0x8902" at DUT0.

Note

After configuring the CFM service on the eth0 interface of DUT1, it will begin to send CFM datagrams that will be received on the eth0 interface of DUT0. Since this interface is a port of the br0 bridge and also since the CFM service is not configured on it, these received CFM datagrams are forwarded by the bridge, regardless of their content.

Step 4: Set the following configuration in DUT1:

set service cfm domain TEST_DOMAIN level 5
set service cfm domain TEST_DOMAIN service TEST_SERVICE sender-id chassis
set service cfm domain TEST_DOMAIN service TEST_SERVICE continuity-check interval 1s
set service cfm domain TEST_DOMAIN service TEST_SERVICE mep 20 interface eth0
set service cfm domain TEST_DOMAIN service TEST_SERVICE mep 20 rmep 10

CFM Bridge Forward Above Level CCM

Description

In this scenario, the CFM service is configured on port eth0 of the bridge br0 of DUT0. So, the bridge should forward the CFM datagrams received on said port, as long as they come with a level field higher than the one configured in eth0.

Scenario

Step 1: Set the following configuration in DUT0:

set interfaces bridge br0 address 10.0.0.1/24
set interfaces ethernet eth0 bridge-group bridge br0
set service cfm domain TEST_DOMAIN level 6
set service cfm domain TEST_DOMAIN service TEST_SERVICE sender-id chassis
set service cfm domain TEST_DOMAIN service TEST_SERVICE continuity-check interval 1s
set service cfm domain TEST_DOMAIN service TEST_SERVICE mep 10 interface eth0
set service cfm domain TEST_DOMAIN service TEST_SERVICE mep 10 rmep 20

Step 2: Set the following configuration in DUT1:

set interfaces ethernet eth0 address 10.0.0.2/24

Step 3: Run command traffic dump monitor interface br0 filter "ether[12:2] == 0x8902" at DUT0.

Note

After configuring the CFM service on the eth0 interface of DUT1, it will begin to send CFM datagrams that will be received on the eth0 interface of DUT0. Since this interface is a port of the br0 bridge and also since the CFM service is configured on it, these received CFM datagrams are forwarded by the bridge, since the level parameter configured in DUT1 is higher than that configured in DUT0.

Step 4: Set the following configuration in DUT1:

set service cfm domain TEST_DOMAIN level 7
set service cfm domain TEST_DOMAIN service TEST_SERVICE sender-id chassis
set service cfm domain TEST_DOMAIN service TEST_SERVICE continuity-check interval 1s
set service cfm domain TEST_DOMAIN service TEST_SERVICE mep 20 interface eth0
set service cfm domain TEST_DOMAIN service TEST_SERVICE mep 20 rmep 10

CFM Bridge Not Forward Equal Level CCM

Description

In this scenario, the CFM service is configured on port eth0 of the bridge br0 of DUT0. So the bridge should not forward CFM datagrams received on said port, when they come with a level field equal to the one configured in eth0.

Scenario

Step 1: Set the following configuration in DUT0:

set interfaces bridge br0 address 10.0.0.1/24
set interfaces ethernet eth0 bridge-group bridge br0
set service cfm domain TEST_DOMAIN level 6
set service cfm domain TEST_DOMAIN service TEST_SERVICE sender-id chassis
set service cfm domain TEST_DOMAIN service TEST_SERVICE continuity-check interval 1s
set service cfm domain TEST_DOMAIN service TEST_SERVICE mep 10 interface eth0
set service cfm domain TEST_DOMAIN service TEST_SERVICE mep 10 rmep 20

Step 2: Set the following configuration in DUT1:

set interfaces ethernet eth0 address 10.0.0.2/24

Step 3: Run command traffic dump monitor interface br0 filter "ether[12:2] == 0x8902" at DUT0.

Note

After configuring the CFM service on the eth0 interface of DUT1, it will begin to send CFM datagrams that will be received on the eth0 interface of DUT0. Since this interface is a port of the br0 bridge and also since the CFM service is configured on it, these received CFM datagrams could be forwarded by the bridge. However, they are not forwarded and are processed by DUT0, since the level field in them is the same as the one configured in DUT0.

Step 4: Set the following configuration in DUT1:

set service cfm domain TEST_DOMAIN level 6
set service cfm domain TEST_DOMAIN service TEST_SERVICE sender-id chassis
set service cfm domain TEST_DOMAIN service TEST_SERVICE continuity-check interval 1s
set service cfm domain TEST_DOMAIN service TEST_SERVICE mep 20 interface eth0
set service cfm domain TEST_DOMAIN service TEST_SERVICE mep 20 rmep 10

CFM Bridge Not Forward Below Level CCM

Description

In this scenario, the CFM service is configured on port eth0 of the bridge br0 of DUT0. So the bridge should not forward CFM datagrams received on said port, when they come with a level field lower than the one configured in eth0.

Scenario

Step 1: Set the following configuration in DUT0:

set interfaces bridge br0 address 10.0.0.1/24
set interfaces ethernet eth0 bridge-group bridge br0
set service cfm domain TEST_DOMAIN level 6
set service cfm domain TEST_DOMAIN service TEST_SERVICE sender-id chassis
set service cfm domain TEST_DOMAIN service TEST_SERVICE continuity-check interval 1s
set service cfm domain TEST_DOMAIN service TEST_SERVICE mep 10 interface eth0
set service cfm domain TEST_DOMAIN service TEST_SERVICE mep 10 rmep 20

Step 2: Set the following configuration in DUT1:

set interfaces ethernet eth0 address 10.0.0.2/24

Step 3: Run command traffic dump monitor interface br0 filter "ether[12:2] == 0x8902" at DUT0.

Note

After configuring the CFM service on the eth0 interface of DUT1, it will begin to send CFM datagrams that will be received on the eth0 interface of DUT0. Since this interface is a port of the br0 bridge and also since the CFM service is configured on it, these received CFM datagrams could be forwarded by the bridge. However, they are not forwarded and are discarded by DUT0, since the level field in them is lower than that configured in DUT0.

Step 4: Set the following configuration in DUT1:

set service cfm domain TEST_DOMAIN level 5
set service cfm domain TEST_DOMAIN service TEST_SERVICE sender-id chassis
set service cfm domain TEST_DOMAIN service TEST_SERVICE continuity-check interval 1s
set service cfm domain TEST_DOMAIN service TEST_SERVICE mep 20 interface eth0
set service cfm domain TEST_DOMAIN service TEST_SERVICE mep 20 rmep 10