CCIE – STP 802.1D – Fundamentals

INTRODUCTION For resiliency purposes, Layer2 topologies are designed and deployed in a physical loop. Unlike the IP protocol which uses the TTL field as a built-in mechanism for preventing packets from looping endlessly through the network, the Ethernet protocol does not provide such facility and therefore, unless we can prevent a layer2 loop, the following problems would occur: Broadcast storms – endless broadcast of frames through the entire L2 domain Hosts end-up receiving duplicates frames from different switches Unstable mac-address tables due to continuous host mac address learning on different ports The STP (Spanning Tree Protocol) was developed to avoid…

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Cisco ISE Deployment Notes

As with any deployment, having a good design in place is the foundation of achieving a successful deployment. In this blog I will be putting together a few notes to keep in mind when designing and deploying Cisco ISE appliance. COMMUNICATION Whilst communication is not strictly part of the actual design, it is nonetheless an important area to address. Deploying access controls in any network is a risky business indeed. Why? Well … access control here should be a good clue! Furthermore, prior to even starting the design, you must fully understand what the requirements are and communicate the limitation within…

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