Juniper and Cisco Comparisons of RIB, LIB, FIB and LFIB Tables
A quick overview before we start: It starts off with the ingress packet. As a packet comes into the Label Edge Router (LER) the Layer2 frame header will be examined and forwarded to the appropriate table, based on the Ethertype field to determine what protocol in payload of the Ethernet frame. The table interactions in principle are the same between …
Use case for MPLS in the Enterprise for PCI Compliance
MPLS is today’s only form of scalable network virtualization we have for now. I personally think the promise of something called SDN will move into that space soon but until then, we need network virtualization. PCI is a joke. It is a racket by Visa and banks to spread fear without any brains behind the architecture. PCI DSS v2.0 soon …
Basic MPLS/VPN with Cisco IOS
This is a quick tutorial for basic MPLS/VPN with Cisco IOS configuration. The tutorial exemplifies basic PE to P to PE configuration on three Cisco 7200s running in GNS3 with IOS. R2 is configured as a route reflector P node and R4, R6 and R3 are PE node route reflector clients. The IGP is OSPF with R2 as the ABR. Loopback1 …
How Headers Encapsulate in the OSI stack
How Headers Encapsulate in the OSI stack: Part 2 of some refreshers. We send application data or payload by encapsulating or framing each layer within the previous layer. We looked at each one individually and now here is how they look when each layer is wrapped inside the previous layer. Figure 1. Here is how application data gets passed to each …
How I Learned to Hate the DCI
How I Learned to Hate the DCI: Layer 2 data center interconnects (DCI) is still alive and well. I blame VMware with vMotion and now every other Hypervisor vendor on the planet. Live workload migration is certainly vital to most operations. The further up the stack that happens the more flexibility you have with choosing more layers beneath you to reach for in …
What are Ethernet, IP and TCP Headers in Wireshark Captures
If I could go back in time when I was a n00b kid wanting to go from zero to a million in networking, the one thing I would change would be spending about 6 months on the fundamentals of networking headers and framing before ever touching a single peice of vendor gear. Ethernet, IP and Transport headers (L2-L4) are the …
Why the NOS will decouple
Over the next couple of years some of us expect the networking industry to have some fairly significant changes. There are really two options: A distributed approach we have today or a controller based centralized model. We have today just that, autonomous devices building adjacencies to one another, exchanging what it hopes are the best healthy paths to send next hop traffic …
