Webinar topic: Up and Running SSH Service Presenter: Achmad Mardiansyah, M. Taufik Nurhuda In this webinar series, Up and Running SSH Service Please share your feedback or webinar ideas here: http://bit.ly/glcfeedback Check our schedule for future events: https://www.glcnetworks.com/en/schedule/ Follow our social media for updates: Facebook, Instagram, YouTube Channel, and telegram also discord Recording available on Youtube https://youtu.be/8Y0NsleBFRg

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UP and RUNNING
SSH service
GLC collaboration webinar,
9 nov 2021
Achmad Mardiansyah
M. Taufik nurhuda
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Source: wikipedia.com

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Agenda
● Introduction
● Review prerequisite knowledge
● SSH application
● SSH implementation
● Q & A
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introduction
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What is GLC?
● Garda Lintas Cakrawala (www.glcnetworks.com)
● Based in Bandung, Indonesia
● Areas: Training, IT Consulting
● Certified partner for: Mikrotik, Ubiquity, Linux foundation
● Product: GLC radius manager
● Regular event
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Trainer Introduction
● Name: Achmad Mardiansyah
● Base: bandung, Indonesia
● Linux user since 1999, mikrotik user since 2007, UBNT
2011
● Mikrotik Certified Trainer
(MTCNA/RE/WE/UME/INE/TCE/IPv6)
● Mikrotik/Linux Certified Consultant
● Website contributor: achmadjournal.com, mikrotik.tips,
asysadmin.tips
● More info:
http://au.linkedin.com/in/achmadmardiansyah
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Past experience
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● 2021 (Congo DRC, Malaysia): network support,
radius/billing integration
● 2020 (Congo DRC, Malaysia): IOT integration,
network automation
● 2019, Congo (DRC): build a wireless ISP from
ground-up
● 2018, Malaysia: network revamp, develop billing
solution and integration, setup dynamic routing
● 2017, Libya (north africa): remote wireless migration
for a new Wireless ISP
● 2016, United Kingdom: workshop for wireless ISP,
migrating a bridged to routed network

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About GLC webinar?
● First webinar: january 1, 2010 (title:
tahun baru bersama solaris - new year
with solaris OS)
● As a sharing event with various topics:
linux, networking, wireless, database,
programming, etc
● Regular schedule
● Irregular schedule: as needed
● Checking schedule:
http://www.glcnetworks.com/schedule
● You are invited to be a presenter
○ No need to be an expert
○ This is a forum for sharing: knowledge,
experiences, information
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Please introduce yourself
● Your name
● Your company/university?
● Your networking experience?
● Your general experience?
● Your expectation from this course?
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Prerequisite
● This presentation some prerequisite knowledge
● We assume you already know:
○ Networking in general
○ Computer network
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Review prerequisite knowledge
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7 OSI layer & protocol
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● OSI layer Is a conceptual model from ISO
(International Standard Organization) for project
OSI (Open System Interconnection)
● When you send a message with a courier, you
need to add more info to get your message arrived
at the destination (This process is called
encapsulation)
● What is protocol
○ Is a set of rules for communication
○ Available on each layer
● Communication consist of series encapsulation
○ SDU: service data unit (before PDU)
○ PDU: protocol data unit (after header is added)

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Layered model (TCP/IP vs ISO) and encapsulation
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/ datagram

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Layer 4 header (which one is TCP?)
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Layer 3 header (which one is IPv4?)
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Ethernet header (which is the MTU?)
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802.11 header
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Did you notice?
● There is a big overhead on encapsulation process
● More encapsulation means less payload?
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Layers in internet communication
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Source: APNIC

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Security and encryption
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General Security Aspects (CIA)
● Confidentiality. prevents
unauthorized use or
disclosure of information
● Integrity. safeguards the
accuracy and
completeness of
information
● Availability. authorized
users have reliable and
timely access to information
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AAA security
• Authentication: only registered user can
access
– What you know: username and password
– What you have: token, sms
– What you are: retina scan, fingerprint
• Authorization: define rights of a user
– Access control
– Data access control
– Restriction
– Type of Service
• Accounting: recording of what user is doing
(useful for billing/reporting)
– Traffic volume
– Online time
– Session
– Log: login, logout
Mainly implemented using radius
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Goals of Information Security (CIA)
● Confidentiality. prevents
unauthorized use or
disclosure of information
● Integrity. safeguards the
accuracy and
completeness of
information
● Availability. authorized
users have reliable and
timely access to information
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Security mechanism…
Source: william stalling, network security essentials

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Cryptography - encryption
● practice and study of techniques for
secure communication in the presence
of third parties.
● cryptography is about constructing and
analyzing protocols that prevent third
parties or the public from reading
private messages
● General implementation:
○ Start with asymmetric encryption, to transfer
shared-key
○ Switch to symmetric encryption
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Source:
medium/com/hackernoon

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Secure shell (SSH)
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A bit of history, accessing remote nodes...
Remote access protocols
● Command line interface:
○ Lighter, faster
○ Less bandwidth
○ Example:
■ Telnet
■ Rsh (remote shell)
○ Issue: no security (plain text) → alternatives :
SSH
● GUI
○ Require higher bandwidth
○ slower
○ Example:
■ VNC
■ Remote desktop
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SSH
● An alternative of insecure protocol (telnet, rsh)
● Open standard: RFC 4250
● Security feature:
○ Asymmetric encryption for initial connection
○ Symmetric encryption for data exchange
○ Authentication:
■ key-based authentication
■ password-based authentication
● Implementation:
○ Openssh (openbsd community)
○ Solaris SSH
○ Other ssh
○
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LIVE practice
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preparation
● SSH client
● SSH parameters
○ SSH address
○ SSH port
○ SSH username
○ SSH password
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Q & A
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Interested? Just come to our training...
● Topics are arranged in systematic and logical way
● You will learn from experienced teacher
● Not only learn the materials, but also sharing experiences, best-practices, and
networking
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End of slides
● Thank you for your attention
● Please submit your feedback: http://bit.ly/glcfeedback
● Find our further event on our website : https://www.glcnetworks.com/en/
● Like our facebook page: https://www.facebook.com/glcnetworks
● Slide: https://www.slideshare.net/glcnetworks/
● Discord (bahasa indonesia): (https://discord.gg/6MZ3KUHHBX)
● Recording (youtube): https://www.youtube.com/c/GLCNetworks
● Stay tune with our schedule
● Any questions?
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