Tips

Tips

• Configuring MPLS -- Cisco CCIP MPLS certification: Lesson 5

  In addition to understanding MPLS theory, you must be able to configure routers for MPLS in order to pass the CCIP 642-611 - Implementing Cisco MPLS Exam. The configuration can apply to customer edge (CE) routers, provider edge (PE) routers or ...  Continue Reading

• Understanding IMS (IP Multimedia Subsystem)

  IMS (IP Multimedia Subsystem) is an emerging architectural framework, based on SIP and IP, for offering multimedia and VoIP services, as well as fixed mobile convergence.  Continue Reading

• Optical networks: Core network design best practices

  Core optical network design must take into consideration network requirements specific to the core, including a high degree of aggregation, low reconfigurability, and large geographic scope, while confronting such challenges as router adjacency, ...  Continue Reading

• Using Ethernet as carrier backbone transport

  Carrier Ethernet is making progress as a backbone transport technology, but there are challenges that must be addressed. The main issues, including maintaining scalability in large Ethernet networks, providing QoS to applications, and improving ...  Continue Reading

• Understanding MPLS -- Cisco CCIP MPLS certification: Lesson 1

  Learn skills required for the MPLS portion of the Cisco CCIP certification. These skills are tested in the CCIP 642-611 Implementing Cisco MPLS Exam. The first lesson in the series explains what you need to know to pass the Cisco CCIP certification ...  Continue Reading

• Network monitoring essentials for service provider networks

  Network monitoring in service provider networks involves different tools, including systemic, end-to-end, device-level, and high- and low-level approaches. Learn about the pros and cons in this tip.  Continue Reading

• Service provider billing system fundamentals

  Billing systems for service providers vary considerably in their focus and complexity. This tip looks at the fundamentals of working with billing systems.  Continue Reading

• Service provider network management systems essentials

  Service provider network management systems are discussed, including their main goals: multi-vendor, multi-device access through a uniform interface, fault correlation and filtering, and end-to-end provisioning and management.  Continue Reading

• DNS monitoring: If it's slow, everything is slow

  Techniques for monitoring DNS performance, and the impact on applications when it is not performing properly, are explored in this tip.  Continue Reading

• ISDN protocols, components and router options

  Integrated Services Digital Network (ISDN) provides for digital transmission over ordinary telephone copper wire as well as over other media uses. In this continuation of his tip on ISDN implementation, Chris Partsenidis discusses the OSI Layers, ...  Continue Reading

• TCP/IP troubleshooting: A structured approach -- Using Netdiag.exe

  Limitations of the Repair feature of Windows network connections can be overcome by using Netdiag.exe, a network connectivity troubleshooting tool that is part of the Windows Support Tools. Netdiag runs a more extensive series of tests than the ...  Continue Reading

• VPN security: Hiding in plain sight, using network encryption

  Sensitive data in transit is subject to hacking attacks unless you protect it using some type of encryption. In this tip from Burton Group analyst Jeff Young, learn how network encryption using SSL, IPsec or other types of VPNs can keep your company...  Continue Reading

• Dynamic routing essentials

  Learn how dynamic routing works and the most important routing protocols -- OSPF, EIGRP, RIP and BGP -- as well as how to configure them.  Continue Reading

• MPLS traffic engineering essentials

  MPLS (Multi-protocol Label Switching) traffic engineering basics are presented in this tip.  Continue Reading

• Border Gateway Protocol (BGP) troubleshooting: Advanced approach

  This tip on troubleshooting Border Gateway Protocol (BGP) takes an advanced approach and details how to work with Internet service provider (ISP) networks.  Continue Reading

• Border Gateway Protocol (BGP) troubleshooting: Simple approach

  In BGP troubleshooting, a structured approach can quickly lead you from initial problem diagnosis to the solution. This article focuses on a simple scenario with a single BGP-speaking router in your network.  Continue Reading

• Introduction to Border Gateway Protocol (BGP)

  Border Gateway Protocol (BGP) is the routing protocol that makes the Internet work. This tip explains how BGP works.  Continue Reading

• Virtual routing and forwarding (VRF) extends virtual networks

  Virtual networks are the backbone of virtual systems, linking the servers and storage that together constitute the virtual system. But virtual networks -- and therefore virtual systems -- are often limited to a single facility. Virtual routing and ...  Continue Reading

• Understanding the ISDN standard

  Integrated Services Digital Network (ISDN) is a digital telephone standard designed to replace analogue connections by utilizing ordinary copper wires that are used in standard analogue telephone systems. Learn how Integrated Services Digital ...  Continue Reading

• Wireless security -- Defending Wi-Fi clients

  When it comes to wireless security, considerable attention has been paid to encrypting data, authenticating users, restricting access, and detecting rogue access points. As these network and link defenses improve, however, attackers have started to ...  Continue Reading

• Managing Windows networks using scripts -- The basics

  Learning to use scripts can make the life of a network administrator a lot easier by allowing you to automate daily administration tasks. This tip begins a series on using scripts to manage Windows networks.  Continue Reading

• Configure Cisco wireless bridges for point-to-point networking

  Point-to-point wireless bridging is ideal for many business networks. In this tip, learn how point-to-point wireless bridging can help you, the pros and cons of using it, and the configuration of the Cisco wireless bridges that make it work. The ...  Continue Reading

• TCP/IP troubleshooting: A structured approach -- Repairing network connections

  Learn how the Repair feature works for repairing network connections on Windows platforms in this tip from the WindowsNetworking.com series on TCP/IP troubleshooting.  Continue Reading

• OSI: Securing the Stack, Layer 8 -- Social engineering and security policy

  Network security is essential at every layer of the OSI model, including the mythical eighth layer, where users interact with technology. Since hackers can use social engineering to exploit people, it is important to train your users and implement ...  Continue Reading

• Reduce branch office threats in 10 steps

  Many organizations host business-critical applications in branch offices, but doing so exposes them to many new threats. Here we examine the potential threats to your branch offices and discuss 10 surefire ways to reduce or mitigate them.  Continue Reading

• 4G wireless broadband will use many technologies

  4G is pushing wireless into a new role as the default for broadband connectivity, encompassing technologies from Wi-Fi to WiMax, CDMA, UMTS and EV-DO.  Continue Reading

• Wireless Internet access -- 3G vs. Wi-Fi

  Most road warriors have just two truly viable alternatives for wireless Internet access: 3G and Wi-Fi. In this tip, Lisa Phifer covers the pros and cons of 3G and Wi-Fi for coverage, convenience, capacity, control and cost.  Continue Reading

• TCP/IP troubleshooting: A structured approach -- Troubleshoot routing tables

  Learn how routing tables work and how to troubleshoot routing problems in Windows-based networks in this tip courtesy of WindowsNetworking.com.  Continue Reading

• Troubleshooting a DHCP server

  Learn how to troubleshoot a DHCP server to discover why it might fail to lease IP addresses and the solutions to those problems in this tip.  Continue Reading

• QoS classification and marking for VoIP infrastructures

  QoS for VoIP requires classification and marking as an essential component for establishing a reliable infrastructure.  Continue Reading

• Understanding wireless antennas -- Part 2

  Upgraded antennas can improve wireless LAN performance, reach and security.  Continue Reading

• How routers work

  Routers are essential to carrying network traffic, but how do they work? In this tip, you'll get perspective on how routing fits into the OSI model. You'll also learn how routers use routing tables to direct IP packets, find the best route to a ...  Continue Reading

• QoS components: A closer look

  A large component to a successful voice over IP (VoIP) infrastructure is effectively deploying a quality of service (QoS) model. QoS components entail classification and marking, congestion management, congestion avoidance, policing and shaping, and...  Continue Reading

• Network summarization -- Supernetting and wildcard masks

  Supernetting allows one routing table entry to represent an aggregation of networks. Network engineers need to understand supernetting, how to read routes received from other providers and how to create an access list that references these multiple ...  Continue Reading

• NAC -- Strengthening your SSL VPN

  Many companies have augmented or even replaced IPsec VPNs with secure remote access solutions based on SSL. Given that SSL VPNs can be used from unmanaged home or public PCs, it is critical to assess the remote endpoint's security when deciding ...  Continue Reading

• VLANs -- Controlling wired and wireless traffic

  Today, most business networks rely on virtual LANs (VLANs) to partition Ethernets and control the destinations reached by each worker. As users begin to shift between Ethernet and Wi-Fi throughout the work day, it makes sense to apply VLANs to both ...  Continue Reading

• Understanding wireless antennas - part 1

  Types of wireless LAN antennas, including omni-directional monopole and dipole antennas, are explained in this tip.  Continue Reading

• OSI: Securing the Stack, Layer 7 -- Applications

  Domain Name System (DNS) wasn't designed to handle today's security threats, making it a prime target at Layer 7 -- the application layer -- of the OSI model. In this tip, learn how DNS works and some of the ways hackers attack it, including ...  Continue Reading

• Understanding the FTP PORT command

  Port 20 is assigned to FTP data. Unfortunately, most FTP data sessions do not actually use port 20. Learn to decode port data and use the port command in this tip.  Continue Reading

• Prepare your networks for the Daylight Saving Time (DST) shift

  The Daylight Saving Time shift on March 11 will require preparation to keep your networks running smoothly. Are you ready? In this tip, Tom Lancaster reminds you how Daylight Saving Time works and explains how to re-configure your Cisco routers and ...  Continue Reading

• TCP/IP troubleshooting: A structured approach -- Introduction

  This tip from WindowsNetworking.com describes a structured approach for troubleshooting connectivity problems with TCP/IP networks. This is the first of a series of articles on TCP/IP troubleshooting  Continue Reading

• Cisco wireless access point configuration from scratch

  Learn what the Cisco 1242 wireless access point can do for you and how to configure one from scratch. This tip covers basic security settings, enabling the wireless radios, and how to make a successful connection. The 1242AG is a powerful ...  Continue Reading

• OSI: Securing the Stack, Layer 6 -- Encryption

  SSL or TLS encryption takes place at the presentation layer, Layer 6 of the OSI model. In this tip, learn why encryption is so important and how certain hacker attacks can still circumvent SSL or TLS and threaten your networks.  Continue Reading

• Managing streaming protocols on your network

  To manage user access to streaming media, you first must understand the protocols that deliver streaming media across the network. Learn more about RTP, RTSP, RTCP and other protocols in this tip -- and find out why merely blocking access may not ...  Continue Reading

• Routing: Five common, easily avoided errors

  Router configuration errors don't have to take down your network. Learn five common routing mistakes -- and how to avoid them -- in this tip.  Continue Reading

• Router Expert: Building a WLAN proxy server, implementing ASR

  Using application service redirection (ASR) in the wireless LAN environment provides guest users enough information to be able to get access without the need for direct support.  Continue Reading

• IEEE 802.11n: Research carefully before deploying

  Before deploying the IEEE 802.11n wireless standard, consider how the new Wi-Fi technology will affect your entire network.  Continue Reading

• Router Expert: Building a WLAN proxy server, implementing WPAD

  Router expert Michael Martin continues his discussion of building a WLAN proxy server by explaining how to implement Web Proxy Auto Discovery Protocol (WPAD), which will allow guest users to automatically discover the wireless network.  Continue Reading

• Cisco WLAN design best practices

  Wireless LAN (WLAN) technology has built-in security features, but a one-size-fits-all approach won't ensure adequate security for your organization. This tip provides best practices for designing your security architecture, including user community...  Continue Reading

• VPN operating system interoperability -- configure VPNs with Unix

  Learn how to configure IPsec VPNs on various platforms and ensure interoperability. In our first example, we configure two IBM pSeries Unix (AIX) servers.  Continue Reading

• Cisco IOS IP routing -- dynamic routing

  Dynamic routing is an essential part of Cisco IOS IP network routing. In this tip, David Davis explains how dynamic routing works, discusses the most important routing protocols -- OSPF, EIGRP, RIP and BGP -- and teaches network engineers how to ...  Continue Reading

• OSI: Securing the Stack, Layer 4 -- Fingerprinting

  At Layer 4 of the OSI model, the transport layer, a major security threat is fingerprinting. Learn how active and passive fingerprinting can endanger your network -- and what you can do to prevent fingerprinting -- in this tip, part of our "Securing...  Continue Reading

• MPLS load sharing and high availability, Part 2: IP routing

  MPLS has become a trusted transport option for convergent networks that require guaranteed levels of service, but successful implementation can require increased levels of redundancy to support failover. Robbie Harrell discusses how to enable high ...  Continue Reading

• LAN administration guide

  LAN administration is an arduous task and your responsibilities often involve many different aspects and may include many tasks. This guide will help you with each step and task.  Continue Reading

• Checklist: Define requirements for new networking applications

  In some companies, the in-house software development staff commonly develops and deploys applications outside the knowledge of the IT staff -- which can have dire consequences for the network. In this tip, Brien Posey explains why implementations go...  Continue Reading

• Wireless connections with ad hoc networks

  Ad hoc wireless networking in Windows Vista with the IPv6 protocol has its risks, but it also has several built-in security mechanisms. In this tip, Brien Posey explains how these security features help counteract some risks of wireless networks.  Continue Reading

• Cisco IOS IP routing: Static routes

  Whether you are a network engineer or a student preparing for Cisco certification, it's important to understand how routers work. In this series on Cisco IOS IP routing, David Davis explains the differences between static and dynamic routing and ...  Continue Reading

• IP addressing and subnetting: Calculate a subnet mask using the subnet's formula

  IP addressing and subnetting are an important part of networks. Learn how the subnet's formula works and why it's important to know how to calculate the subnet mask "longhand."  Continue Reading

• MPLS load sharing and high availability

  Multiprotocol Label Switching (MPLS) can be used to create a redundant network architecture, enabling high availability. In this tip, gain a better understanding of MPLS and learn the various components that must be considered when architecting MPLS...  Continue Reading

• OSI: Securing the Stack, Layer 3 -- The role of ICMP

  Michael Gregg examines the security vulnerabilities of Internet Control Message Protocol (ICMP) and how to help secure OSI Layer 3, the network layer.  Continue Reading

• How IPsec provides secure communications

  IPsec provides secure site-to-site VPNs, remote access and host-to-host communication. In this tip, we peek inside the tunnel and examine how IPsec works.  Continue Reading

• QoS: The hidden cost

  Quality of Service (QoS) technology may not necessarily deliver what you've bargained for. In this edition of The Connected Edge, Loki Jorgenson explains how to examine ROI for QoS, what you can expect QoS to deliver, and when to choose another path...  Continue Reading

• Network test plan: Checklist for architecture changes

  For every change you make to your network architecture, you should have a test plan and a backout plan. In this tip, learn how to build a test plan and review a sample checklist of things to include.  Continue Reading

• How SSL and TLS secure network transactions

  SSL and TLS are protocols that were developed primarily to protect Web transactions, but they can be used to protect any type of network traffic that utilizes TCP at the transport layer, including the popular SSL VPN. In this tip, learn how SSL and ...  Continue Reading

• Measuring network hardware utilization

  Monitoring your network goes beyond just keeping tabs on your servers. You also need to monitor your hardware, such as routers and switches, to tell not only that these types of devices are functional, but also that they are not being saturated by ...  Continue Reading

• Router Expert: Building a WLAN proxy server, DHCP services: Part 1

  Router expert Michael Martin discusses DHCP implementation options and provides sample configurations to support various SSID network models in this continuation of his series on building a WLAN proxy server.  Continue Reading

• Staging labs for network engineering

  Making changes to your network is less scary with adequate planning and staging, and go even more smoothly if you have a staging lab. In this tip, Tom Lancaster explains how and why such labs can be useful, then provides advice for designing and ...  Continue Reading

• IP addressing and subnetting: What network administrators need to know

  IP addressing and subnetting are an important part of networks. Learn about how IP addresses work, subnet masks, classful vs. classless IP addresses, default gateways and more.  Continue Reading

• Network cabling documentation

  Network cabling documentation with dedicated documenation software can keep your cables from becoming a big mess.  Continue Reading

• OSI: Securing the stack, Layer 2 -- Understanding the role of ARP

  Security expert Michael Gregg continues his layer-by-layer discussion of OSI model network security with this tip on the vulnerabilities present in Layer 2, the Data Link Layer, and specifically addresses the Address Resolution Protocol.  Continue Reading

• Network engineering overview: Detailed design considerations

  Implementing architectural concepts and dealing with detailed network designs must be second nature to the network engineer. In the conclusion of our tip series on things network engineers need to know to be effective, Tom Lancaster provides some ...  Continue Reading

• Network engineering overview: Policy and process

  Policy and process may seem like dull and superfluous activities, but they exist to improve communication between different departments of your company. In the third installment of his series on things network engineers need to know to be effective,...  Continue Reading

• Troublesome TCP behavior and network latency

  This tip series delves deep into the myth of bandwidth. Part 6 concludes the series by exploring how the TCP transport can cause latency in the network.  Continue Reading

• How round-trip time and limiting data rate impact network performance

  This tip reviews how network parameters such as round-trip time and limiting data rate affect network performance.  Continue Reading

• How network path congestion and delayed ACKs affect network performance

  This tip delves deep into the bandwidth myth. In part 3, we analyze how multiple effects and multiple causes complicate troubleshooting of network performance.  Continue Reading

• NASA space probes, throughput and error probability

  This tip delves deep into the myth of bandwidth. Part 4 demonstrates how in an environment such as NASA's space probes, there isn't much tolerance for network latency -- and introduces how errors can slow down network performance.  Continue Reading

• OSI: Securing the stack, Layer 1 -- Physical security threats

  Security expert Michael Gregg kicks off his layer-by-layer discussion of OSI model network security with this tip on securing Layer 1 against physical security threats.  Continue Reading

• BackTrack: The gotta-have, free, network security tool you've never heard of

  Get the power of Linux-based security tools on Windows with this free suite of open source security tools. Contributor and vulnerability assessment expert Kevin Beaver introduces BackTrack and explains its network security testing features.  Continue Reading

• Duplex mismatch

  What is duplex, and what is the difference between half and full duplex? What is a duplex mismatch? How can autonegotiation help or hurt your network? How can you resolve duplex conflicts? In this tip, David Davis helps networking engineers and ...  Continue Reading

• IPSec and NAT incompatibility

  Learn why Authentication Header (AH) doesn't work with Network Address Translation (NAT) or Port Address Translation (PAT) and that Encapsulating Security Payload (ESP) is also incompatible with PAT.  Continue Reading

• Network engineering overview: Techniques for making changes

  Network engineers are often faced with the task of making changes to the network with minimal downtime. Whether you are upgrading an Ethernet switch or adding a whole new building to your network, this tip surveys some of the decisions you need to ...  Continue Reading

• VPNs for disaster recovery: IPsec vs. SSL

  Using a VPN as a failover mechanism when a primary communications link may be unavailable due to a disaster can be a smart move -- as well as an easy one to implement. In this tip, learn about the pros and cons of IPsec and SSL VPN options for ...  Continue Reading

• Network Access Quarantine Control vs. Network Access Protection

  With the number of mobile devices and remote workers growing, network quarantining has been a popular topic lately. Contributor and NAQC expert Jonathan Hassell compares the features of NAQC with the forthcoming NAP program and advises on if and ...  Continue Reading

• Troubleshooting wireless networks: A systematic approach

  Troubleshooting wireless networks can take up a lot of time for network operations staff with a wireless LAN (WLAN) environment. Wireless guru Lisa Phifer discusses the tools and processes involved and breaks down how to approach and resolve ...  Continue Reading

• VPN maintenance and management

  Once a VPN is installed and running, it is generally too late to understand what resources will be involved in the VPN's ongoing maintenance and management. In this tip, an overview for the third chapter of our VPN All-in-One Guide, Robbie Harrell ...  Continue Reading

• DNS for a wireless network: Router Expert

  DNS services are essential for building a secure wireless LAN. Our Router Expert provides complete instructions for setting up a DNS server, including implementing BIND, configuring a non-authoritative server and creating zone files.  Continue Reading

• T1 vs. VoIP for branch office connectivity

  Learn how to decide between a T1, fractional T1 and VoIP for connecting branch offices.  Continue Reading

• 3G: The CDMA alternative

  CDMA2000 is a third-generation (3G) mobile wireless technology that can support mobile data communications at speeds ranging from 144 Kbps to 2 Mbps. This column discusses the history and specifications of CDMA and explores its benefits.  Continue Reading

• Understanding VPN technologies and capabilities

  Virtual Private Networks (VPNs) are the mainstay of the mobile environment. Enterprises across the world are looking for and finding a multitude of ways to provide the remote, mobile end user with secure access to corporate computing facilities and ...  Continue Reading

• OpenVPN: Simplified, IPsec-like open source security

  Confused by IPsec? Try OpenVPN, an open source, SSL-based, cross-platform compatible, modular network that works with virtually every firewall.  Continue Reading

• WAN optimization and bottlenecks: Is the WAN really the weakest link?

  "How much traffic" is no longer a good enough measure of WAN bandwidth. In this tip, Carrie Higbie looks at how today's ever-increasing expectations for data transfer rates require increased attention to WAN optimization, and suggests how ...  Continue Reading

• Duplex mismatch: Why duplex conflicts plague the network, part 1

  Duplex mismatch problems -- caused by two ends of the Ethernet attempting a full-duplex connection, resulting in packet loss -- simply will not go away. After a decade of plaguing IP networks, duplex conflicts still seem to be the single worst ...  Continue Reading

• Wi-Fi versus WiMAX

  Wi-Fi and WiMAX are hot wireless technologies currently experiencing an enormous increase in deployments, products and services -- but they're also easily confused. Here, Robbie Harrell examines the difference between the two technologies in terms ...  Continue Reading

• How to move an SSL certificate between Exchange servers

  SearchExchange.com contributor Serdar Yegulalp provides step-by-step instructions on how to move an SSL certificate from one Exchange server to another, and explains a couple of gotchas to watch out for during the process.  Continue Reading

• Security and the TCP/IP stack

  Each layer of TCP/IP has security mechanisms, protocols, and applications. This tip describes the more popular ones that are associated with each layer of TCP/IP.  Continue Reading

• UMTS: The 3G upgrade path to GSM

  UMTS (Universal Mobile Telecommunications Service) is a 3G broadband, packet-based transmission of text, digitized voice, video, and multimedia.  Continue Reading

• Cisco PIX firewall configuration from scratch

  Cisco PIX firewall configuration is discussed in this step-by-step tip. Learn how to configure a new PIX, out of the box. You will configure passwords, IP addresses, network address translation (NAT) and basic firewall rules.  Continue Reading

• SSL or IPsec VPNs: Considerations for comparison

  Robbie Harrell discusses some of the questions one must consider when evaluating whether to choose Secure Socket Layer (SSL) instead of the more traditional IPsec.  Continue Reading

• Freeware captures raw sockets and TCP/IP packets

  SmartSniff allows you to capture TCP/IP packets that pass through your network adapter, and view the captured data as sequence of conversations between clients and servers.  Continue Reading

• Four strategies for secure extranets

  Extranets can be beneficial for conducting e-commerce, but if they aren't properly secured, they can pose serious risks to you, your business partners and customers. In this tip network security expert Mike Chapple provides four tactics for locking ...  Continue Reading