Uplink Failure Detection (UFD)
Uplink failure detection (UFD) provides detection of the loss of upstream connectivity and, if used with network interface controller (NIC)
teaming, automatic recovery from a failed link.
Feature Description
A switch provides upstream connectivity for devices, such as servers. If a switch loses its upstream connectivity, downstream devices also
lose their connectivity. However, the devices do not receive a direct indication that upstream connectivity is lost because connectivity to
the switch is still operational.
UFD allows a switch to associate downstream interfaces with upstream interfaces. When upstream connectivity fails, the switch disables
the downstream links. Failures on the downstream links allow downstream devices to recognize the loss of upstream connectivity.
For example, as shown in the following illustration, Switches S1 and S2 both have upstream connectivity to Router R1 and downstream
connectivity to the server. UFD operation is shown in Steps A through C:
•
In Step A, the server configuration uses the connection to S1 as the primary path. Network traffic flows from the server to S1 and then
upstream to R1.
•
In Step B, the upstream link between S1 and R1 fails. The server continues to use the link to S1 for its network traffic, but the traffic is
not successfully switched through S1 because the upstream link is down.
•
In Step C, UFD on S1 disables the link to the server. The server then stops using the link to S1 and switches to using its link to S2 to
send traffic upstream to R1.
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Uplink Failure Detection (UFD)
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Summary of Contents for S3048-ON
Page 1: ...Dell Configuration Guide for the S3048 ON System 9 11 2 5 ...
Page 137: ...0 Gi 1 1 Gi 1 2 rx Flow N A N A 0 0 No N A N A yes Access Control Lists ACLs 137 ...
Page 142: ...Figure 10 BFD Three Way Handshake State Changes 142 Bidirectional Forwarding Detection BFD ...
Page 241: ...Dell Control Plane Policing CoPP 241 ...
Page 287: ... RPM Synchronization GARP VLAN Registration Protocol GVRP 287 ...
Page 428: ...Figure 53 Inspecting the LAG Configuration 428 Link Aggregation Control Protocol LACP ...
Page 477: ...Figure 73 Configuring Interfaces for MSDP Multicast Source Discovery Protocol MSDP 477 ...
Page 478: ...Figure 74 Configuring OSPF and BGP for MSDP 478 Multicast Source Discovery Protocol MSDP ...
Page 483: ...Figure 77 MSDP Default Peer Scenario 2 Multicast Source Discovery Protocol MSDP 483 ...
Page 484: ...Figure 78 MSDP Default Peer Scenario 3 484 Multicast Source Discovery Protocol MSDP ...
Page 745: ...Figure 104 Single and Double Tag TPID Match Service Provider Bridging 745 ...
Page 746: ...Figure 105 Single and Double Tag First byte TPID Match 746 Service Provider Bridging ...