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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.
Uplink Failure Detection (UFD)
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Содержание S4820T
Страница 1: ...Dell Configuration Guide for the S4820T System 9 8 0 0 ...
Страница 282: ...Dell 282 Control Plane Policing CoPP ...
Страница 569: ...Figure 62 Inspecting Configuration of LAG 10 on ALPHA Link Aggregation Control Protocol LACP 569 ...
Страница 572: ...Figure 64 Inspecting a LAG Port on BRAVO Using the show interface Command 572 Link Aggregation Control Protocol LACP ...
Страница 573: ...Figure 65 Inspecting LAG 10 Using the show interfaces port channel Command Link Aggregation Control Protocol LACP 573 ...
Страница 617: ...mac address table static multicast mac address vlan vlan id output range interface Microsoft Network Load Balancing 617 ...
Страница 622: ...Figure 81 Configuring Interfaces for MSDP 622 Multicast Source Discovery Protocol MSDP ...
Страница 623: ...Figure 82 Configuring OSPF and BGP for MSDP Multicast Source Discovery Protocol MSDP 623 ...
Страница 624: ...Figure 83 Configuring PIM in Multiple Routing Domains 624 Multicast Source Discovery Protocol MSDP ...
Страница 629: ...Figure 86 MSDP Default Peer Scenario 2 Multicast Source Discovery Protocol MSDP 629 ...
Страница 630: ...Figure 87 MSDP Default Peer Scenario 3 630 Multicast Source Discovery Protocol MSDP ...
Страница 751: ...10 11 5 2 00 00 05 00 02 04 Member Ports Te 1 2 1 PIM Source Specific Mode PIM SSM 751 ...
Страница 905: ...Figure 112 Single and Double Tag First byte TPID Match Service Provider Bridging 905 ...
Страница 979: ...6 Member not present 7 Member not present Stacking 979 ...
Страница 981: ...storm control Storm Control 981 ...
Страница 999: ... Te 1 1 0 INCON Root Rootguard Te 1 2 0 LIS Loopguard Te 1 3 0 EDS Shut Bpduguard Spanning Tree Protocol STP 999 ...
Страница 1103: ...Figure 134 Setup OSPF and Static Routes Virtual Routing and Forwarding VRF 1103 ...