Cisco Cisco Catalyst Blade Switch 3030 for Dell White Paper
Design Guide
The spanning tree topology is calculated and one of the primary parameters involved in
this equation is the location of the root switch. Determining the position of the root switch
in the network allows the network administrator to create an optimized forwarding path for
traffic. Root Guard is a feature designed to control the location of the root switch.
The aggregation switches should employ the spanning-tree guard root command on the
port channel interfaces connected to the blade switches.
this equation is the location of the root switch. Determining the position of the root switch
in the network allows the network administrator to create an optimized forwarding path for
traffic. Root Guard is a feature designed to control the location of the root switch.
The aggregation switches should employ the spanning-tree guard root command on the
port channel interfaces connected to the blade switches.
Step 2. Allow only those VLANs that are necessary on the port channel between the aggregate
and the blade switches.
Use the switchport trunk allowed vlan vlanID command to configure the port channel
interfaces of the aggregate switch to allow only those VLANs indicated with the vlanID
option.
Use the switchport trunk allowed vlan vlanID command to configure the port channel
interfaces of the aggregate switch to allow only those VLANs indicated with the vlanID
option.
Additional Cisco Catalyst Blade Switch 3130 Configuration
Step 1. Enable BPDU Guard on the internal server ports of the switch.
Use the spanning-tree bpduguard enable command to shut down a port that receives a
BPDU when it should not be participating in the spanning tree.
Step 2. Allow only those VLANs that are necessary on the port channels between the aggregate
and the blade switches.
Use the switchport trunk allowed vlan vlanID command to configure the port channel
interfaces of the switch to allow only those VLANs indicated with the vlanID option.
Use the switchport trunk allowed vlan vlanID command to configure the port channel
interfaces of the switch to allow only those VLANs indicated with the vlanID option.
The following convergence tests were conducted against this alternative topology:
●
Uplink failure and recovery between Switch-A and the primary root
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Uplink failure and recovery between Switch-B and the secondary root
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Failure and recovery of Switch-A and Switch B
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Failure and recovery of the primary and secondary root switches
These tests yielded results similar to the recommended topology. Layer 2 convergence occurs in
approximately 1 second. As stated previously, recovery at Layer 3 is dependent on the HSRP
settings of the aggregate switches (see “Recommended Topology” section). In our testbed, the
failure of the active HSRP device typically increased the convergence time to 5 seconds.
approximately 1 second. As stated previously, recovery at Layer 3 is dependent on the HSRP
settings of the aggregate switches (see “Recommended Topology” section). In our testbed, the
failure of the active HSRP device typically increased the convergence time to 5 seconds.
This design supports traffic monitoring using SPAN and/or RSPAN. For example, a network
analysis device connected to the external ports on the front of the Cisco Catalyst Blade Switch
3130 may capture locally mirrored traffic. Alternatively, RSPAN traffic may be carried on the Cisco
Catalyst Blade Switch 3130 uplinks if bandwidth utilization is not a concern. For the steps to
configure traffic monitoring, refer to the “Configuration Details” section.
analysis device connected to the external ports on the front of the Cisco Catalyst Blade Switch
3130 may capture locally mirrored traffic. Alternatively, RSPAN traffic may be carried on the Cisco
Catalyst Blade Switch 3130 uplinks if bandwidth utilization is not a concern. For the steps to
configure traffic monitoring, refer to the “Configuration Details” section.
Configuring the Aggregate Switches
Complete the following steps on the aggregate switches:
Step 1. VLAN configuration
Step 2. RPVST+ configuration
Step 3. Primary and secondary root configuration
© 2008 Cisco Systems, Inc. All rights reserved. This document is Cisco Public Information.
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