Native VLAN support breaks this barrier so that you can connect a port to both VLAN-aware and VLAN-unaware stations. Such ports are
referred to as hybrid ports. Physical and port-channel interfaces may be hybrid ports.
Native VLAN is useful in deployments where a Layer 2 port can receive both tagged and untagged traffic on the same physical port. The
classic example is connecting a voice-over-IP (VOIP) phone and a PC to the same port of the switch. The VOIP phone is configured to
generate tagged packets (with VLAN = VOICE VLAN) and the attached PC generates untagged packets.
NOTE:
When a hybrid port is untagged in a VLAN but it receives tagged traffic, all traffic is
accepted.
NOTE:
You cannot configure an existing switchport or port channel interface for Native VLAN. Interfaces must have no other
Layer 2 or Layer 3 configurations when using the
portmode hybrid
command or a message similar to this displays:
% Error:
Port is in Layer-2 mode Gi 5/6.
To configure a port so that it can be a member of an untagged and tagged VLANs, use the following commands.
1
Remove any Layer 2 or Layer 3 configurations from the interface.
INTERFACE mode
2
Configure the interface for Hybrid mode.
INTERFACE mode
portmode hybrid
3
Configure the interface for Switchport mode.
INTERFACE mode
switchport
4
Add the interface to a tagged or untagged VLAN.
VLAN INTERFACE mode
[tagged | untagged]
Enabling Null VLAN as the Default VLAN
In a Carrier Ethernet for Metro Service environment, service providers who perform frequent reconfigurations for customers with changing
requirements occasionally enable multiple interfaces, each connected to a different customer, before the interfaces are fully configured.
This presents a vulnerability because both interfaces are initially placed in the native VLAN, VLAN 1, and for that period customers are able
to access each other's networks. Dell Networking OS has a Null VLAN to eliminate this vulnerability. When you enable the Null VLAN, all
ports are placed into it by default, so even if you activate the physical ports of multiple customers, no traffic is allowed to traverse the links
until each port is place in another VLAN.
To enable Null VLAN, use the following command.
•
Disable the default VLAN, so that all ports belong to the Null VLAN until configured as a member of another VLAN.
CONFIGURATION mode
default-vlan disable
Default: the default VLAN is enabled (
no default-vlan disable
).
Virtual LANs (VLANs)
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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 ...