Cisco Support in Spain After End of Life

Ports Are the Visible Limit, and Rarely the Real One

When a Spanish network starts behaving badly under load, the first thing checked is usually port utilisation, and it is usually fine. The constraint that matters more on a mature network is table capacity: the finite hardware space a switch has for MAC addresses, for routing entries, and for access-list and quality-of-service rules. That space is fixed in silicon when the platform is designed, and it does not appear on the front panel.

A Full Address Table Does Not Report an Error

When a switch runs out of room to record which port a destination sits behind, it does not refuse traffic. It floods, sending frames to every port in the broadcast domain because it no longer knows the right one. Every device on that segment absorbs traffic it should never have seen, throughput falls for everyone, and no interface counter identifies the cause. The switch is doing precisely what it is designed to do when it does not know an answer.

Rule capacity fails in two different ways

Access-list and policy entries live in specialised memory with its own limit. When that limit is reached, an entry either fails to install in hardware at all, or it falls back to being handled by the control-plane processor. The first case means a security or quality-of-service policy that appears configured is not being enforced. The second means the traffic it matches is processed orders of magnitude more slowly than everything else, which presents as an intermittent and unreproducible performance complaint.

The growth that consumes it is invisible

These tables are filled by things nobody logs as expansion. Virtual machines and containers each consume address entries. Wireless clients come and go in numbers no one counts. Access-list entries are appended one at a time over years by different people for different reasons. Because no new ports were installed, the platform continues to look correctly sized in every document that describes it.

What ICD Supplies for Cisco Estates in Spain

Catalyst and Nexus platforms and line cards whose table capacity suits the network as it actually is, supervisor engines that hold the forwarding tables for a chassis, UCS blade and rack components, optics matched to platform and distance, and power supplies sized for populated cards and powered devices. We quote against platform and module identifiers rather than a model name, and ship from Cairo. Every unit is tested and identified by its own serial, with one to three years of warranty.