Руководство По Проектированию для Cisco Cisco Nexus 5010 Switch
Design Guide
Figure 8.
vPC VLANs and Orphaned Ports
For a VLAN to be on the peer link, it must exist on both vPC peers, and it must appear in the allowed list of the switch
port trunk. If either of these conditions is not met, the VLAN isn’t displayed when you enter the command show vpc
port trunk. If either of these conditions is not met, the VLAN isn’t displayed when you enter the command show vpc
brief
, nor is it a vPC VLAN.
A vPC port is a port that is assigned to a vPC channel group. A non-vPC port, also known as orphaned port, is a port
that is not part of a vPC.
that is not part of a vPC.
Figure 8 shows different types of Orphaned Ports. Switch 2 connects to the Cisco Nexus 7000 with a regular
Spanning-Tree configuration, hence one link is forwarding and one link is blocking. These links connect to the Cisco
Nexus 7000 with “orphaned” ports.
Spanning-Tree configuration, hence one link is forwarding and one link is blocking. These links connect to the Cisco
Nexus 7000 with “orphaned” ports.
Server 6 connects to the Cisco Nexus 7000 with an active/standby teaming configuration. The ports that Server 6
connects to on the Cisco Nexus 7000 are “orphaned” ports.
connects to on the Cisco Nexus 7000 are “orphaned” ports.
Duplicate Frames Prevention Technique in vPC
One of the most important forwarding rules of vPC is the fact that a frame that entered the vPC peer switch from the
peer link cannot exit the switch out of a vPC member port (except if this is coming from an orphaned port).
peer link cannot exit the switch out of a vPC member port (except if this is coming from an orphaned port).
Figure 9, shows switch 3 and switch 4 connected to switches 1 and 2 with vPCs Po51 and Po52. A host sending
either an unknown unicast or a broadcast that gets hashed to port Ethernet2/2 on switch 3 on PortChannel 52. Switch
2 receives the broadcast and needs to forward it to the peer link for the potential orphan ports on switch 1 to receive
it.
either an unknown unicast or a broadcast that gets hashed to port Ethernet2/2 on switch 3 on PortChannel 52. Switch
2 receives the broadcast and needs to forward it to the peer link for the potential orphan ports on switch 1 to receive
it.
Upon receiving the broadcast, switch 1 detects that this frame is coming from a vPC member port. Therefore, it does
not forward it to port 2/10, or a duplicate frame on switch 3 would be created.
not forward it to port 2/10, or a duplicate frame on switch 3 would be created.
If a host on switch 4 sends a broadcast, switch 2 will correctly forward it to Po51 on port 2/9 and place it on the peer
link. Switch 1 will prevent this broadcast frame from exiting onto ports 2/9 or 2/10 because this frame entered switch 2
from a vPC member port. Should port 2/2 on switch 3 go down, the masking information sent by switch 2 gets
updated in order for switch 1 to forward the frame out of port 2/9.
link. Switch 1 will prevent this broadcast frame from exiting onto ports 2/9 or 2/10 because this frame entered switch 2
from a vPC member port. Should port 2/2 on switch 3 go down, the masking information sent by switch 2 gets
updated in order for switch 1 to forward the frame out of port 2/9.
© 2010 Cisco Systems, Inc. All rights reserved. This document is Cisco Public Information.
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