CST3607 Class Notes 2022-05-05

News & Tools

• AT&T Takes Steps to Mitigate Botnet Found Inside Its Network – AT&T is battling a modular malware called EwDoor on 5,700 VoIP servers, but it could have a larger wildcard certificate problem.
• ‘Double-Extortion’ Ransomware Damage Skyrockets 935%

Exam 3

Chapter 10: Security: Access Control Lists (ACL)

• You will need to decode an ACL to determine:
  • which IP addresses or networks are being denied or allowed,
  • which protocols are being denied or allowed,
  • whether the rule applies to inbound our outbound traffic,
  • etc.
• Standard Access Lists
  • Standard Access Lists can check for what in the IP packet?
  • Is a Standard ACL applied closest to the destination or closest to the source?
  • What are the access-list numbers for a Standard ACL?
• Extended Access Lists
  • Extended Access Lists can check for what in the IP packet?
  • Is an Extended ACL applied closest to the destination or closest to the source?
  • What are the access-list numbers for an Extended ACL?
• What is an Implicit Deny?
• An Inbound access list is applied to inbound packets on an interface, before being routed.
  • Why is an inbound access list applied before the packet is routed?
• An Outbound access list is applied to outbound packets on an interface.
• Why must an access list must be applied to an interface to be effective?
• Configuring ACLs
  • access-list
  • access-group
  • access-class
• Security Appliances
• Determine the Subnet Block Sizes
  • Use the block size to determine the subnet ranges

Chapter 11: Network Address Translation (NAT)

Network Address Translation (NAT) allows many inside IP addresses to be represented by some smaller number of outside/public IP addresses.

Types of NAT, and how they work:

• Static
• Dynamic
• Port Address Translation (PAT) a.k.a. NAT Overload
• What type of address translation can use only one address to allow thousands of hosts to be translated globally?
• In the following output, what type of NAT is being used? 
  ip nat pool todd-nat 170.168.10.10 170.168.10.20 netmask 255.255.255.0
• Instead of the netmask command, you can use the _____________ statement.

NAT terms

• An inside local address is before or after translation?
• An inside global address is before or after translation?
• Outside Local
• Outside Global

CCNA CCNP Training – No confusion with IP NAT Inside Outside Local Global

• Using ACLs with NAT
  • What are the Cisco IOS commands to define the NAT ACL, and then to apply the ACL to an interface?
• Configure and verify NAT for given network requirements
  • NAT Diagnostic Commands and output
  • Which command will show you the translation table?
  • Which command can you use to show the NAT translations as they occur on your router?
  • Which command will clear all your NAT entries from the translation table?
  • Which command can be used for troubleshooting and displays a summary of the NAT configuration, as well as counts of active translation types, and hits to an existing mapping?
  • Which commands must be used on your router interfaces before NAT will translate addresses?
  • Once you create a pool for the inside locals to use to get out to the global Internet, what is the command to allow them access to the pool?
• Operation of IP Data Networks
  • Predict the data flow between two hosts across a network
• Identify the basic operation of NAT
  • Purpose
  • Pool
  • Static
  • one-to-one
  • Overloading
  • Source addressing
  • One-way NAT

Chapter 12: IP Services

• SNMP
  • Which version of SNMP provides the best security?
  • Which layer of the OSI Reference Model does SNMP function?
  • What is the MIB?
  • How does SNMP use the MIB?
• syslog
  • What message types are sent to the syslog server?
  • What is the default syslog facility level?
  • What is the command to enable syslog with debugging?
• NTP
  • What’s command to specify the source to synchronize time with?
• ICMP
• Cisco Discovery Protocol (CDP)
  • What is the command to determine the IP address of a directly connected neighbor?
• Link Layer Discovery Protocol (LLDP)
• Secure Shell (SSH)
  • What commands are required when configuring SSH on your router?

OSI Reference Model

Cisco IOS Diagnostic Commands

• show ip interface brief
  • What would the “status” and “protocol” columns display if an interface was not enabled?
  • What would the “status” and “protocol” columns display when an interface is “shutdown?”
  • What would the “status” and “protocol” columns display if an Ethernet interface is enabled, and configured, but the other end of the connection was shutdown?
  • What would the “status” and “protocol” columns display if a Serial interface is enabled, and configured, but the other end of the connection was shutdown?
  • What would the “status” and “protocol” columns display if an interface is enabled, and configured, but the interface was not connected to another device?
  • What would the “status” and “protocol” columns display for a Serial DCE interface, where the clock rate was not set or was zero?

Read / Watch / Do

CCNA Certification Study Guide, Volume 2

• Read Chapter 13: Security, Authentication
• Do the Written Labs
• Answer the Review Questions
  • Do not submit your answers for this chapter. The answers are in Appendix.