Cisco Systems 3750E Limitations with Other Features

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Catalyst 3750-E and 3560-E Switch Software Configuration Guide
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Chapter16 Configuring Private VLANs
Configuring Private VLANs
•Do not configure ports that belong to a PAgP or LACP EtherChannel as private-VLAN ports. While
a port is part of the private-VLAN configuration, any EtherChannel configura tion for it is inactive.
•Enable Port Fast and BPDU guard on isolated and community host ports to prevent STP loops due
to misconfigurations and to speed up STP convergence (see Chapter 20, “Configuring Optional
Spanning-Tree Features”). When enabled, STP applies th e BPDU guard feature to all Port
Fast-configured Layer 2 LAN ports. Do not enable Port Fast and BPDU guard on promiscuous ports.
•If you delete a VLAN used in the private-VLAN configuration, the private-VLAN por ts associated
with the VLAN become inactive.
•Private-VLAN ports can be on different network devices if the devices are trunk-connected and the
primary and secondary VLANs have not been removed from the trunk.
Limitations with Other Features
When configuring private VLANs, remember these limitations with other features:
Note In some cases, the configuration is accepted with no error messages, but the commands have no effect.
•Do not configure fallback bridging on switches with private VLANs.
•When IGMP snooping is enabled on the switch (the default), the switch or switch stack supports no
more than 20 private-VLAN domains.
•Do not configure a remote SPAN (RSPAN) VLAN as a private-VLAN primary or secondary VLAN.
For more information about SPAN, see Chapter30, “Configuring SPAN and RSPAN.”
•Do not configure private-VLAN ports on interfaces configured for these other features:
– dynamic-access port VLAN membership
�� Dynamic Trunking Protocol (DTP)
– Port Aggregation Protocol (PAgP)
– Link Aggregation Control Protocol (LACP)
– Multicast VLAN Registration (MVR)
– voice VLAN
– Web Cache Communication Protocol (WCCP)
•You can configure IEEE 802.1x port-based authentication on a private-VLAN port, but do not
configure 802.1x with port security, voice VLAN, or per-user ACL on private-VLAN ports.
•A private-VLAN host or promiscuous port cannot be a SPAN destination port. If you configure a
SPAN destination port as a private-VLAN port, the port becomes inactive.
•If you configure a static MAC address on a promiscuous port in the primary VLAN, you must add
the same static address to all associated secondary VLANs. If you configure a static MAC address
on a host port in a secondary VLAN, you must add the same static MAC address to the associated
primary VLAN. When you delete a static MAC address from a private-VLAN port, you must
remove all instances of the configured MAC address from the private VLAN.