Cisco WS-X6K-SUP1A-PFC= Software Guide - Page 199

Chapter 11 Configuring VLANs Configuring Private VLANs Table 11-3 Modules with Ports Listed by ASIC Groups (continued) Module Number WS-X6348-RJ-45 Description 48-port 10/100TX RJ-45 WS-X6024-10FL-MT 24-port 10BASE-FL MT-RJ Ports by ASIC Ports 1-12 Ports 13-24 Ports 25-36 Ports 37-48 Ports 1-12 Ports 13-24 • Isolated and community ports should run BPDU guard features to prevent spanning tree loops due to misconfigurations. • Primary VLANs and associated isolated/community VLANs must have the same spanning tree configuration. This configuration maintains consistent spanning tree topologies between associated primary, isolated, and community VLANs and avoids possible loss of connectivity. These priorities and parameters automatically propagate from the primary VLAN to the isolated and community VLANs. • You can create private VLANs that run in MISTP mode as follows: - If you disable MISTP, any change to the configuration of a primary VLAN propagates to all corresponding isolated and community VLANs, and you cannot change the isolated or community VLANs. - If you enable MISTP, you can only configure the MISTP instance with the primary VLAN. Changes will be applied to the primary VLAN and will propagate to the isolated and community VLANs. • In networks with some switches using MAC address reduction, and others not using MAC address reduction, STP parameters do not necessarily propagate to ensure that the spanning tree topologies match. You should manually check the STP configuration to ensure that the primary, isolated, and community VLANs' spanning tree topologies match. • If you enable MAC address reduction on a Catalyst 6000 series switch, you might want to enable MAC address reduction on all the switches in your network to ensure that the STP topologies of the private VLANs match. Otherwise, in a network where private VLANs are configured, if you enable MAC address reduction on some switches and disable it on others (mixed environment), you will have to use the default bridge priorities to make sure that the root bridge is common to the primary VLAN and to all its associated isolated and community VLANs. Be consistent with the ranges employed by the MAC address reduction feature regardless of whether it is enabled on the system. MAC address reduction allows only discrete levels and uses all intermediate values internally as a range. You should disable a root bridge with private VLANs and MAC address reduction, and configure the root bridge with any priority higher than the highest priority range used by any nonroot bridge. • BPDU guard mode is system wide and is enabled after you add the first port to a private VLAN. • You cannot configure a destination SPAN port as a private VLAN port and vice versa. • A source SPAN port can belong to a private VLAN. • You can use VLAN-based SPAN (VSPAN) to span primary, isolated, and community VLANs together, or use SPAN on only one VLAN to separately monitor egress or ingress traffic. • You cannot use a remote SPAN VLAN (RSPAN) for a private VLAN. 78-13315-02 Catalyst 6000 Family Software Configuration Guide-Releases 6.3 and 6.4 11-17