News & Tools
- A Cyberattack Hobbles Atlanta, and Security Experts Shudder by Alan Blinder and Nicole Perlroth, March 27, 2018
- Why Are Cities So Vulnerable to Cyber Attack? by Linda Poon Mar 30, 2018 #
- Hobby Lobby Exposes Customer Data in Cloud Misconfiguration
- Why You Should Start Using a VPN (and How to Choose the Best One for Your Needs)
- Adventures in Networking: Part history, part tutorial, all interesting by Paul Lutus
- Zero-configuration networking (zeroconf) is a set of technologies that automatically creates a usable computer network based on the Internet Protocol Suite (TCP/IP) when computers or network peripherals are interconnected. It does not require manual operator intervention or special configuration servers.
Subnetting Tutorial & Reference
Troubleshooting & Verifying Networks
Self-Evaluation
- At this point in the semester, you should be confident in your understanding of Cisco IOS, routing protocols, etc., to complete this Lab-04 (OSPF, Serial, DHCP), using only the network diagram as your guide, with 100% accuracy, in less than 30 minutes.
- If that’s not the case, then you must practice, practice, practice, to gain the necessary skills and confidence.
- Practice makes improvement.
OSPF Hello and Dead Interval
OSPF uses hello packets and two timers to check if a neighbor is still alive or not:
- Hello Interval: defines how often we send the hello packet.
- Dead Interval: defines how long we should wait for hello packets before we declare the neighbor dead.
Set the hello and dead intervals on interfaces which communicate with neighboring routers.
(config)# interface FastEthernet 0/0 (config-if)# ip ospf hello-interval <seconds> (config-if)# ip ospf dead-interval <seconds> [ Defaults to four times the value of the hello interval ]
Show the Router ID, Hello, and Dead Intervals on an Interface
2621-A# show ip ospf interface s0/0
Serial0/0 is up, line protocol is up
Internet address is 14.25.143.9/30, Area 0
Process ID 100, Router ID 1.1.1.1, Network Type POINT-TO-POINT, Cost: 64
Transmit Delay is 1 sec, State POINT-TO-POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
Hello due in 00:00:02
Index 2/2, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 1 , Adjacent neighbor count is 1
Adjacent with neighbor 2.2.2.2
Suppress hello for 0 neighbor(s)
2621-A#
Reference
VLAN (Virtual Local Area Network)
- VLAN 1 is the default Ethernet VLAN
- VLANs 1002 through 1005 are automatically created and cannot be deleted
- What are the maximum number of VLANs, including the reserved VLANs?
- Trunking
- What is the purpose of a Trunk port?
- IEEE 802.1Q Encapsulation
InterVLAN Routing
- A Stub router, One-armed router or Router on a Stick (RonS) is a router configured to route traffic between virtual local area networks (VLANs).
- It has only a single Ethernet NIC that is part of two or more Virtual LANs, enabling them to be joined.
- The physical interface is divided into logical interfaces (known as sub-interfaces), one for each VLAN, configured as trunk interfaces.
- Search: Router on a Stick
SVI (Switched Virtual Interface)
- A Switch Virtual Interfaces (SVI) represents a logical Layer 3 interface on a switch.
- VLANs divide broadcast domains in a LAN environment. Whenever hosts in one VLAN need to communicate with hosts in another VLAN, the traffic must be routed between them. This is known as inter-VLAN routing. On Layer 3 switches it is accomplished by the creation of Layer 3 interfaces (SVIs).
VLAN Diagnostic Commands
- S1# show vlan
- S1# show vlan brief
- S1# show interface trunk
- S1# show interfaces switchport
- S1# show interface fa0/15 switchport
- S1# show running-config
- S1# show arp
- S1# clear arp
VLAN Resources
- What is a VLAN? How to Setup a VLAN on a Cisco Switch
- VLANs and Trunks for Beginners – Part 1 (video)
- How to Configure VLANs in the Cisco IOS by David Davis (video) (InterVLAN routing)
- Cisco’s Overview of Routing between VLANs
- How to define the VLANs allowed on a trunk link
- S1(config-if)# switchport trunk allowed vlan remove 5-10,12
- InterVLAN Routing – Routing between VLAN Networks
Hands-On Lab-06: Troubleshooting Single Area OSPF
- Use Cisco Packet Tracer v8.x
- You must be present for this class, and submit your 100% Packet Tracer file, to get full credit for this lab.
- This lab is due tonight before you sign off.
- Log into Cisco Packet Tracer
- Download and unzip the Lab-06 Packet Tracer file
- Rename the Packet Tracer with your last and first names
- Open Lab-06 Packet Tracer in Packet Tracer
- Save As: CST3607 Lab-06 YourLastName, YourFirstName v01
- Read the instructions!!!!!
- E-mail your 100% Lab-06 to me before you sign off. Subject: CST3607 Lab-06 YourLastName, YourFirstName
- 1st password to log into a switch or router is the “console” password
- 2nd password to get into privileged mode is the secret password
Read / Watch / Do
CCNA Certification Study Guide, Volume 2
- Read Chapter 10 Access Lists
- Do the Written Labs
- Answer the Review Questions
- Do not submit your answers for this chapter. The answers are in Appendix.
Read / Watch
- Cisco Router Access-Lists Part 1 (Fundamentals): Cisco Router Training 101 by soundtraining.net
- Cisco Router Access-Lists Part 2 (Advanced): Cisco Router Training 101 by soundtraining.net
- Access-list – Practice Test
- MicroNugget: Wildcard Masks by Keith Barker
- Understanding Access Control List Logging (cisco.com)
- Quizlet: Chapter 12: Security by Sidd_ (ACLs (Access Control Lists))
- Quizlet.com – CCNA 3 chap 6 by kodiak117 (VLANs)