* Accurate root bridge selection increases the stability of the spanning tree
Netcordia Founder and CEO Terry Slattery has been successfully heading up that company and developing its NetMRI suite of network analysis appliances, but he still wants to do more. That’s why he recently sent me a list of network analysis tips – some of which are incorporated into the company’s intelligent appliances – to detail the approaches or fixes to some common network optimization techniques.
With more than 20 years of experience fine-tuning Cisco and other nets, Slattery wants to periodically contribute his optimization best practices to the network managers at large. For instance, this week he sent me “Network Analysis Tip – Selecting the Correct Root Bridge” – which comes into play with virtual LANs, or .
According to Slattery, accurate root bridge selection will increase the stability of the spanning tree and underlying VLANs. If the appropriate root bridge is not selected, it won’t be able to handle the load and could bring down the entire data center.
“If a low powered switch becomes the root bridge, it may not have sufficient memory or CPU to handle the task and the spanning tree becomes unusable,” Slattery says.
Network managers can manually determine the correct root bridge for VLANs, Slattery says, by “issuing the Cisco CLI command ‘show spanning-tree’ on the switches within each VLAN. The returned address is the MAC address of the root switch. Once the MAC address is determined, it can be correlated with the IP address of the desired switch.” And naturally, NetMRI has a feature that can enable network managers to automate the process.
Stay tuned for potentially more tech tips from Slattery and others in future Network Optimization newsletters.
