Optimize Cisco Layer 3 Switch

I have a Cisco Layer 3 managed switch running on its default IOS configuration, and I want its performance tuned for noticeably faster inter-VLAN traffic and lower latency across the network. At the moment we have several VLANs in place, but routing, spanning-tree parameters, and QoS queues have never been optimized. Traffic occasionally bottlenecks when large file transfers coincide with VoIP or video meetings, so the goal is to streamline the switch’s internal processing and link utilization to improve overall throughput.

Here is how I see the engagement unfolding:

• Review the current running-config (I will supply the sanitized text dump).
• Recommend and apply adjustments to VLAN design, SVIs, dynamic routing or static routes as appropriate, STP settings, EtherChannel or port-channel configurations, and QoS policies.
• Validate improvements with before-and-after metrics—simple ping/iperf tests or NetFlow statistics are acceptable.
• Supply the final running-config, a saved startup-config, and a concise change log so I can replicate the setup if the device is replaced or upgraded.

Acceptance criteria
– Latency between key VLANs reduced and consistent under typical load.
– No loss of connectivity to any existing endpoint.
– Clean, commented configuration file delivered in text format.

All work can be done remotely via SSH or through a change script that I paste into the console during a maintenance window; whichever is easier for you. If your optimisation suggestions also touch on security hardening or management simplification, that is welcome, but the must-have outcome is better network performance.