Chapter 1 What is Network Automation?

o Often decentralized in project folders, file shares, Visio diagrams, Excel spreadsheets, and

local drives. o Sometimes the network itself is the source of truth: the running-configurations of each device

is the only source of information about the network.  Documentation.

o Documentation tends to fall out of date and requires manual updates when changes are made

to the network. o Often missed or overlooked. o Often decentralized. o Rarely referenced by network operators due to above complications.

 Scale.

o Networks are not getting smaller. Internet of Things (IoT), wireless access points, IP phones,

rapid WAN expansion, cloud adoption, and larger data centers are leading to massive enterprise networks. o CLI simply does not scale unless more people are added to manage the network.

 Error-prone.

o Mistakes happen with manual changes. o Requires orchestration of complex changes ensuring the correct order of device and

command entry. o Requires work to be done several times per change. Plan, document, submit, and implement

into production. o Sometimes approval processes or operational mistakes occur where changes are completed

out of order from when they were submitted, causing overwrites or outages.  Large-scale changes.

o Deployment of new features often takes a very long time because of scale or complexity. o New business requirements and device types connecting to the network may require QoS

policy changes leading to rewrite the QoS policy for every device. o Some changes are avoided because the effort required to make a correction or deploy a

feature is too great.  Limitations of available alternatives.

o Aside from CLI or an NMS there are very few alternatives to managing a network. o Newer, intent-based solutions have only recently immerged with little proven capability.

 Talent.

o The complexity of networks has grown along with their size and scale. Virtualization,

multicast, QoS, STP, routing, routing protocols, cloud, security, firewalls, wireless, voice, video, VSS, HSRP, VPN, 802.1x, along with increasingly complicated commands to gather information. o Staffing challenges such as finding certified IT staff or expanding network operations head

count. Every change to the network becomes a challenge as the complexity increases.  Cost.

o Downtime and change window requirements. o Overtime requirements.