Description

Uplink Failure Detection (UFD) provides a mechanism to disable all the associated downlink interfaces when all the uplink interfaces go down, which is very useful in the case of network redundancy for the downlink server going with network adapter teaming.

Figure 1. Uplink Failure Detection

All the network interface cards (NICs) in a network adapter teaming works under stand-by mode with the same IP address. Namely, when the primary link goes down, the server automatically changes to the secondary link. If uplink failure detection is enabled, the switch monitors the uplink interfaces (link-to-monitor interfaces). When all the uplink interfaces go down, the switch will disable all the associated downlink interfaces (link-to-disable interface). When the server detects disabled downlink interfaces on the switch side, it switches over to the secondary link, which helps to quickly detect link failures and reduce network packet loss.

Configuring Uplink Failure Detection

NOTEs:

Only the physical interfaces or LAG interfaces can be configured as UFD uplink interfaces or downlink interfaces, logical interfaces are not supported.
In the same UFD group, the same interface cannot be configured as both the UFD uplink interface and the downlink interface.
The same interface can be configured as the UFD downlink interface only in one UFD group. That is, it is not allowed to configure the same interface as the UFD downlink interface in different UFD groups.

Step 1 Configure the uplink interface to an uplink failure detection group. Repeat this step to add more uplink interfaces to the uplink failure detection group.

set interface ufd <ufd-group-name> link-to-monitor <interface-name>

Step 2 Configure the downlink interface to an uplink failure detection group. Repeat this step to add more downlink interfaces to the uplink failure detection group.

set interface ufd <ufd-group-name> link-to-disable <interface-name>

Step 3 Commit the configurations.

commit

Step 4 View the uplink failure detection configuration information and status.

run show interface ufd

Uplink Failure Detection Configuration Example

Networking Requirements

Figure 2. Uplink Failure Detection Configuration Example

As shown in Figure 2, on the Server, all the network interface cards (NICs) in a network adapter teaming works under stand-by mode with the same IP address. Namely, when the primary link goes down, the server automatically changes to the secondary link.

To quickly detect link failures and reduce network packet loss, uplink failure detection can be enabled on Switch A and Switch B separately to monitor the uplink interfaces (link-to-monitor interfaces) on each side. When all the uplink interfaces on one switch side go down, Switch A/Switch B will disable all the associated downlink interfaces (link-to-disable interface). When the server detects disabled downlink interfaces on one switch side, it switches over to the secondary link. For simplicity, there is only one uplink interface and one downlink interface in each UFD group in this configuration example.

This example does not describe how to configure the dual-homed server or the aggregation switches. Please refer to the documentation for each of these devices for more information.

Procedure

Switch A

Step 1 Configure the uplink interface to an uplink failure detection group.

admin@SwitchA# set interface ufd ufd1 link-to-monitor te-1/1/2

Step 2 Configure the downlink interface to an uplink failure detection group.

admin@SwitchA# set interface ufd ufd1 link-to-disable ge-1/1/1

Step 3 Commit the configurations.

admin@SwitchA# commit

Step 4 View the uplink failure detection configuration information and status. Hence the uplink interface and the downlink interface are up, so in the result the status of Failure Action is Inactive.

admin@SwitchA# run show interface ufd
UFD: ufd1
-----------------------------------------------------
Uplink        : te-1/1/2
Downlink      : ge-1/1/1
Failure Action: Inactive

Switch B

Step 1 Configure the uplink interface to an uplink failure detection group.

admin@SwitchB# set interface ufd ufd1 link-to-monitor te-1/1/2

Step 2 Configure the downlink interface to an uplink failure detection group.

admin@SwitchB# set interface ufd ufd1 link-to-disable ge-1/1/1

Step 3 Commit the configurations.

admin@SwitchB# commit

Step 4 View the uplink failure detection configuration information and status. Hence the uplink interface and the downlink interface are up, so in the result the status of Failure Action is Inactive.

admin@SwitchB# run show interface ufd
UFD: ufd1
-----------------------------------------------------
Uplink        : te-1/1/2
Downlink      : ge-1/1/1
Failure Action: Inactive