1.0 Networking Concepts

1.1 Compare the layers of the OSI and TCP/IP models.

• OSI model:
  • Layer 1 - Physical
  • Layer 2 - Data link
  • Layer 3 - Network
  • Layer 4 - Transport
  • Layer 5 - Session
  • Layer 6 - Presentation
  • Layer 7 - Application
• TCP/IP model:
  • Network Interface Layer
  • Internet Layer
  • Transport Layer
  • Application Layer
  • (Also described as: Link Layer, Internet Layer, Transport Layer, Application Layer)

1.2 Classify how applications, devices, and protocols relate to the OSI model layers.

• MAC address
• IP address
• EUI-64
• Frames
• Packets
• Switch
• Router
• Multilayer switch
• Hub
• Encryption devices
• Cable
• NIC
• Bridge

1.3 Explain the purpose and properties of IP addressing.

• Classes of addresses
  • A, B, C and D
  • Public vs. Private
• Classless (CIDR)
• IPv4 vs. IPv6 (formatting)
• MAC address format
• Subnetting
• Multicast vs. unicast vs. broadcast
• APIPA

1.4 Explain the purpose and properties of routing and switching.

• EIGRP
• OSPF
• RIP
• Link state vs. distance vector vs. hybrid
• Static vs. dynamic
• Routing metrics
  • Hop counts
  • MTU, bandwidth
  • Costs
  • Latency
• Next hop
• Spanning-Tree Protocol
• VLAN (802.1q)
• Port mirroring
• Broadcast domain vs. collision domain
• IGP vs. EGP
• Routing tables
• Convergence (steady state)

1.5 Identify common TCP and UDP default ports.

• SMTP - 25
• HTTP - 80
• HTTPS - 443
• FTP - 20, 21
• TELNET - 23
• IMAP - 143
• RDP - 3389
• SSH - 22
• DNS - 53
• DHCP - 67, 68

1.6 Explain the function of common networking protocols.

• TCP
• FTP
• UDP
• TCP/IP suite
• DHCP
• TFTP
• DNS
• HTTPS
• HTTP
• ARP
• SIP (VoIP)
• RTP (VoIP)
• SSH
• POP3
• NTP
• IMAP4
• Telnet
• SMTP
• SNMP2/3
• ICMP
• IGMP
• TLS

1.7 Summarize DNS concepts and its components.

• DNS servers
• DNS records (A, MX, AAAA, CNAME, PTR)
• Dynamic DNS

1.8 Given a scenario, implement the following network troubleshooting methodology:

• Identify the problem:
  • Information gathering
  • Identify symptoms
  • Question users
  • Determine if anything has changed
• Establish a theory of probable cause
  • Question the obvious
• Test the theory to determine cause:
  • Once theory is confirmed determine next steps to resolve problem
  • If theory is not confirmed, re-establish new theory or escalate
• Establish a plan of action to resolve the problem and identify potential effects
• Implement the solution or escalate as necessary
• Verify full system functionality and if applicable implement preventative measures
• Document findings, actions and outcomes

1.9 Identify virtual network components.

• Virtual switches
• Virtual desktops
• Virtual servers
• Virtual PBX
• Onsite vs. offsite
• Network as a Service (NaaS)