4
S4 receives the VN-Segment ID tagged packet and performs packet lookups. Once the packet destination
port is identified as a VNSEG edge port, S4 uses the VLAN ID corresponding to the VN-Segment ID in
the packet and sends the packet.
If the VN-Segment ID to VLAN mapping does not exist, the packet is dropped.
Note
5
Server B receives the .1Q data packet from Server A.
The same process is followed in the data packets from server B to server A.
Guidelines and Limitations for VN-Segment
VN-Segment has the following guidelines and limitations:
•
The VN-Segment tag is added to traffic egressing FabricPath (FP) links only.
•
Data forwarding semantics is the same as that of the VLANs.
•
The devices must be VN-Segment aware with appropriate hardware support.
•
Leaf switches must be configured for VN-Segment.
•
The Virtual Network Identifier (VNI) is the network global ID, not the VLAN ID.
•
Up to 4K VN-Segments and global VLANs are supported per leaf switch. There are only 4K VLANs.
•
Different leafs can have different mapping to up to support 50K tenants on the fabric, depending on
hardware and software limitations.
•
If compatibility checks fail for the image, ISSD might be rejected .
•
The VLAN-to-VN-Segment mapping must be consistent on the vPC+ peer switches for correct traffic
flow. vPC type 1 consistency checks suspend VLANs on vPC peer swtiches with inconsistent mappings.
Enabling VN-Segment
Procedure
Purpose
Command or Action
Enters global configuration mode.
switch#
configure terminal
Step 1
Installs the FabricPath feature set on the switch.
switch(config)#
install feature-set
fabricpath
Step 2
Enables the FabricPath feature set on the switch.
switch(config)#
feature-set fabricpath
Step 3
Enables the VN-Segment feature on the switch.
switch(config)#
feature
vn-segment-vlan-based
Step 4
Cisco Nexus 6000 Series NX-OS Layer 2 Switching Configuration Guide, Release 7.x
205
Configuring VN-Segment
Guidelines and Limitations for VN-Segment