Verifying 802.1X configuration
Why 802.1X? There was a time when networks were secure islands, used to connect PCs to services they consumed and each other. The network was protected from the outside world by a perimeter firewall: there was only one way in and out. With the explosion…
Stopping Firewall Bypass Attempts
A network user – a senior manager in the business, in the process of writing a heavy report – knocks on the door of the security team’s office. He has an urgent request, to access a server that sits behind a firewall. He speaks to…
Troubleshooting Multicast Traffic Flows
Just what is multicast? How do you set up your network to handle multicast? And how do you troubleshoot it if it fails? Let’s start from the beginning. Unicast Forwarding Typical IP packet forwarding is considered “unicast” – a communication is broken up into IP…
Aligning Spanning Tree and FHRP in the campus LAN
The “typical” site LAN In most networks, a site LAN consists of a number of interconnected Ethernet switches in a regular partial mesh pattern. The topology typically enables high availability of the networked applications. We create redundant links which are not typically used but are…
OSPF Path Cost Consistency
What does OSPF do for me? Open Shortest Path First (OSPF) is a standards-based routing protocol for IPv4. It is used to advertise paths to a network prefix between routers. As a router receives advertisements for prefixes, so it creates a representation of the network…
Verify end-to-end QoS
Verifying Quality of Service is a complex task when delivering applications across a large network. It involves a detailed understanding of the behaviour of many different devices, often from different vendors. This post shows how IP Fabric can help with this onerous task. Quality of…
Spotting Single Points of Failure
Design for availability The fundamental purpose of a data network is to connect users with applications, data producers and consumers with storage. The most desirable feature of a network is to maximise availability of those services to the endpoints that consume them. In order to…
Identifying BGP instability
There are many elements that contribute to the availability of services delivered across any network. Redundancy in the topology, coupled with resilience in the configuration are key. Routing protocols are used to manage that redundancy and failover to backup traffic paths should a failure occur…
Network analysis tools are critical to successful administration
Ever since engineers started operating computer networks, they started to use network analysis tools to measure performance, calculate risks and improve visibility. As technologies in general evolved, so did the tools for their administration. However, it’s become quite common that many operators stick to old-fashioned Command-Line Interface (CLI) only and avoid any automation.
IP Fabric 3.3: Visual Intent Verification
IP Fabric version 3.3. adds capability to visually represent intent-based network verifications among other improvements.