1.1.b (iii) Polarization Concept and Avoidance

Moving on from load-balancing, let's discuss CEF polarization, which is a problem already solved, however is still important to study. Let's take the above diagram where all routers are utilizing the older iteration of CEF without Universal IDs. If 64 flows come into this router, CEF will equally distribute them across its 2 links. The …

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1.1.b (ii) Load Balancing Hash

Each switching path has different capabilities when it comes to load balancing: Process switching (slowest) can only do per packet load balancing (ewww out of order packets) Fast switching (per flow) much better but not perfect CEF switching utilizes a per packet hash which results in a per flow behavior. (Can utilize per packet but …

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1.1.b (i) RIB, FIB, LFIB, Adjacency Table

Routing information Base (RIB): AFter the FIB and adjacency tables are build, the RIB is rarely used. The only time the RIB is ever used is when packets must be processed by the routers CPU (control and management plane traffic cannot be CEF switches as they require processing). To see the RIB contents: sh ip …

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1.1.b Identify Cisco Express Forwarding Concepts

Before discussing CEF one needs to be familiar with how a router actually routes a packet, these are the steps summarized: 1. Packet is received, Frame Check Sequence (FCS) is checked, if passed it moves to step 2. 2. The eth type field is is checked to indicate what the inner packet is, if 0x0800 …

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Ubuntu 17 Onenote Alternative : CherryTree

Finally, I found a suitable replacement for Onenote. Originally when searching for my replacement I immediately looked into Evernote, yet it didn't offer me anything differente compared to Onenote Online (via outlook.com). I wanted something local, with better response. Really I just needed a good way to organize my notes, I didn't need anything fancy. …

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1.1.a (iii) Excluding Specific Platforms Architecture

IOS XE does not run on every platform. Specifically it does not run on 29xx routers, low level ISRs like the 800 or 900 series. It does run on the following though: New Catalyst 9K line Converged Broadband Routers ASR line 42xx, 43xx, 44xx ISR ISRv and CSR1000v