Ufd And Nic Teaming - Dell C9000 Series Networking Configuration Manual

An enabled uplink-state group tracks the state of all assigned upstream interfaces. Failure on an upstream
interface results in the automatic disabling of downstream interfaces in the uplink-state group. As a result,
downstream devices can execute the protection or recovery procedures they have in place to establish
alternate connectivity paths, as shown in the following illustration.
Figure 138. Uplink Failure Detection Example
If only one of the upstream interfaces in an uplink-state group goes down, a specified number of downstream
ports associated with the upstream interface are put into a Link-Down state. You can configure this number
and is calculated by the ratio of the upstream port bandwidth to the downstream port bandwidth in the same
uplink-state group. This calculation ensures that there is no traffic drops due to insufficient bandwidth on the
upstream links to the routers/switches.
By default, if all upstream interfaces in an uplink-state group go down, all downstream interfaces in the same
uplink-state group are put into a Link-Down state.
Using UFD, you can configure the automatic recovery of downstream ports in an uplink-state group when the
link status of an upstream port changes. The tracking of upstream link status does not have a major impact on
central processing unit (CPU) usage.

UFD and NIC Teaming

To implement a rapid failover solution, you can use uplink failure detection on a switch with network adapter
teaming on a server.
For more information, refer to NIC Teaming.
For example, as shown previously, the switch/ router with UFD detects the uplink failure and automatically
disables the associated downstream link port to the server. To continue to transmit traffic upstream, the
server with NIC teaming detects the disabled link and automatically switches over to the backup link in order.
Uplink Failure Detection (UFD) 1124