Problem solve

Problem solve

Get help with specific problems with your technologies, process and projects.

• Using NAT Traversal and IPsec Passthrough together

  NAT Traversal and IPsec Passthrough are two different solutions to tunneling encrypted packets through an NAT-ing device like a firewall. Learn to configure them without conflict. Continue Reading

• Redundant routers and network segmentation

  This tip investigates a routing configuration using a router for each switch -- or redundant router architecture -- on the WAN, and discusses a common failure scenario that is somewhat difficult to defend against: a segmented network. Continue Reading

• Redundancy on the WAN: Routers for backup circuits

  When improving redundancy with a backup WAN circuit between two sites, the network architect must decide whether there should be two routers, with one for each circuit, or whether both circuits should plug into the same router. In this tip, Tom ... Continue Reading

• Understanding the network application environment

  Understanding the network application environment is critical to application performance management. In this tip, learn how application discovery and classification, network analysis, and business drivers affect your network application environment ... Continue Reading

• IPsec VPN clients

  Here's a list of IPsec clients that run on many systems. See what they have to offer and what they are often missing. Continue Reading

• The VPN Expert: VPN client alternatives, part 2 -- PPTP

  Lisa Phifer discusses one widely available type of "free" client: those used in Point-to-Point Tunneling Protocol VPNs.Continue Reading

• Advanced OpenVPN configuration

  This article deals with some features of advanced OpenVPN configuration like protecting clients through a firewall behind a tunnel, distributed compilation through VPN tunnels with distcc and authentication methods.Continue Reading

• Modeling can be key to capacity planning

  Planning for the future of your network sometimes requires rigorous planning and modeling. In this tip, Ed Tittel shows how a free modeling tool just may come to your rescue.Continue Reading

• Configuring a VRF

  Doug Downer demonstrates how to configure a VPN Routing and Forwarding (VRF) in an instance where a service provider needs to keep Internet services separate for two different clients on shared devices.Continue Reading

• Network planning: Bandwidth utilization

  Network planning is explained in this tip on bandwidth utilization.Continue Reading

• Troubleshooting WAN performance issues

  Isolating the root cause of a WAN performance issue is critical, and having the right tools or managed services in place is imperative. Those tools can help determine whether the root cause of the problem lies in the application; the carrier network...Continue Reading

• Disabling IPv6 in Windows Vista -- Pros and cons

  Windows Vista features a dual stack, running IPv4 and IPv6 simultaneously. If your organization is still using only IPv4, there are IPv6 performance and security problems that can be countered by simply turning off IPv6. But there are also reasons ...Continue Reading

• Application performance management: Developing a strategy

  Application performance management is a critical task because application delivery can play a critical role in both revenue generation and corporate functionality. In this tip, learn how to develop a strategy for managing applications on your ...Continue Reading

• Bandwidth: Calculate current and future requirements

  Increased bandwidth, and factors influencing the need for it, are considered in this tip. Network engineers will discover best practices for estimating current and future bandwidth needs.Continue Reading

• Broadband VPN bandwidth issues

  VPN bandwidth presents a serious challenge when the VPN is connected over broadband Internet connections. Vendors tout the ability to provide bandwidth controls and QoS, but you must consider that the traffic will be in the same queue as any other ...Continue Reading

• What salaries and jobs align with CCIE, CCNA, and CCNP certifications?

  The CCIE, CCNA, and CCNP Cisco certifications along with work experience are aligned to these job opportunities and salary ranges according to our training and Cisco certification expert, David Minutella.Continue Reading

• Using MPLS TE to avoid core network congestion

  Telecom service providers with high-bandwidth core networks inevitably face link congestion. To help you deal with router architecture proactively, IP expert Ivan Pepelnjak offers advice on reintroducing virtual circuits in the core IP network using...Continue Reading

• What's the best Cisco router to practice my CCNA and CCNP exams on?

  Our Cisco certification expert recommends the best router for practicing and learning your CCNA and CCNP exams, in this response.Continue Reading

• How does IPv6 benefit current and future applications?

  IPv6 benefits current and future applications on the network. Learn what impact and effects the Internet Protocol version 6 brings, from our IPv4/IPv6 expert.Continue Reading

• What does node-local mean in IPv6 in terms of multicast scope?

  In terms of multicast scopes, learn what node-local means in this definition by our Internet Protocol version 6 (IPv6) expert, Silvia Hagen.Continue Reading

• Difference between circuit-switching and packet-switching in examples

  What is the difference between a circuit switching and packet switching? Our networking fundamentals expert gives examples of packet switching and circuit switching in this response.Continue Reading

• VLANs versus IP subnets: Why use a VLAN over IP subnetting?

  A virtual local area network (VLAN) is better than IP subnetting because its advantage is security. Learn what a VLAN is and how it differs from creating IP subnets, in this expert response from our networking fundamentals expert.Continue Reading

• Why are TCP/IP networks considered unsecured?

  Learn why TCP/IP networks are considered unsecured from our networking security expert, Michael Gregg.Continue Reading

• Can Network Address Translation work without static IP addresses?

  Find out how Network Address Translation (NAT) works with static and dynamic IP addresses and what the most common type of NAT is from our networking fundamentals expert.Continue Reading

• Virtualization to fundamentally change telecom networks

  Virtualization will be the new model for service provider network infrastructure, and if it is effective, carrier revenue will increase while capex and opex decrease. Juniper is leading the way with a new router virtualization switching fabric that ...Continue Reading

• How to link wired LANs using wireless network bridges and APs

  Our wireless networking expert aids an administrator deploy a WLAN in this response to the question "How can I link my wired LANs using ZyXEL's B-3000 access point (AP) and B-420 wireless bridges?"Continue Reading

• Telecom operators need vendor help to justify new investment benefits

  Telecom network operators need to justify the value of new equipment purchases, and vendors need to help them define the benefits if telecom revenue is to recover now that voice is no longer king. The question is: Will vendors step up to the plate ...Continue Reading

• Why error reporting ICMP messages include IP headers and datagram data

  Learn why Internet Control Message Protocol (ICMP) error reports include IP headers and the first 8 bytes of datagram data in this response from our network administration expert.Continue Reading

• Bandwidth allocation: How can I give a download limit for each user?

  To manage bandwidth, learn how to allocate download limits for each user in your network with policy settings on devices, our administration expert advises.Continue Reading

• How wireless network encryption affects signal strength, connectivity

  Our wireless networking expert explains how Wi-Fi encryption could affect signal strength and therefore connection loss, in this expert explanation.Continue Reading

• Network performance and throughput in server virtualization environments

  Network performance and throughput are crucial areas where server virtualization can affect the data center network. These need attention from networking professionals. As organizations expand their use of server virtualization, the data center ...Continue Reading

• How to use Netsh WLAN to configure Windows Server 2008 and Windows Vista wireless connections from t

  Learn how to configure wireless networking connections, specifically, Windows Server 2008 Windows Vista wireless connections, from the command line interface (CLI) using Netsh WLAN. Figure out how to add or delete profiles and connect or disconnect ...Continue Reading

• Telecoms must address three SOA implementation challenges

  To successfully implement SOA, telecom providers must be clear on the main deployment challenges, and keep high performance, scalability, efficient applications automation and boundaries from third parties' top of mind.Continue Reading

• Can neighboring 802.11n and 802.11g networks avoid coexistence problems?

  After an 802.11n migration, our wireless networking expert explains how to avoid coexistence problems with neighboring businesses that still use 802.11g.Continue Reading

• Server virtualization and the impact on network configuration

  Server virtualization delivers sophisticated capabilities that affect performance, scaling and connectivity needs. Solutions have evolved from enabling partitioning of a single computer into multiple virtual servers to enabling virtual servers to be...Continue Reading

• How do VPN concentrators and network access servers (NAS) differ?

  Find out if there's a difference between a virtual private network (VPN) concentrator and a network access server (NAS) in this explanation from our network security expert, Puneet Mehta.Continue Reading

• What keeps unauthorized users from accessing my IP address/Internet?

  Our network security expert explains how to keep unauthorized users from accessing your router's IP address for Internet access in this advice explaining how proxy servers can solve client control issues.Continue Reading

• What is the difference between packet fragmentation in IPv4 and IPv6?

  In this Q&A, our IPv6 expert explains how packet fragmentation differs in IPv6 compared to IPv4.Continue Reading

• What VLAN management software supports multiple vendor platforms?

  Our network administration expert shows you which VLAN network management configuration and automation software supports multiple vendors and platforms, in this expert response.Continue Reading

• How to upgrade Windows Server 2003 to Server 2008

  Use these resources recommended by our network administration expert to upgrade from Windows Server 2003 to Windows Server 2008, in this expert response.Continue Reading

• How to avoid the WPA wireless security standard attack

  The latest crack in wireless Internet security, specifically, the Wi-Fi Protected Access (WPA) security standard, can threaten the safety of enterprise networks and company information or data. This tip shows the best way to avoid being victimized ...Continue Reading

• Which OSI layers are network managers responsible for?

  Learn which layers of the OSI model network managers should be responsible for. Our expert, Lindi Horton, explains where to focus your manual operations, especially regarding automated operation tasks.Continue Reading

• Network bandwidth calculators: What will be my WAN's link speed?

  Use this recommended bandwidth calculator to calculate network latency and your WAN's link speed. Our network administration expert says this tool can simulate 1,000 users in your environment.Continue Reading

• Top Windows Management Instrumentation (WMI) scripting books, websites

  Once you've learned how to write Windows Management Instrumentation (WMI) scripts to manage various aspects of Windows-based networks, check out the top resources recommended for your study. In this tip, Mitch Tulloch lists the best books and ...Continue Reading

• The year's 5 hottest telecom topics and editor's picks

  The past year in telecom was a lot more than ominous recession forecasts and survival tips. From BGP and MPLS to flexible service provisioning, optics and wireless broadband, telecom pros were intensely focused on next-generation networking this ...Continue Reading

• How to calculate subnet masks in IPv6

  Find out from our IPv6 (Internet Protocol Version 6) expert whether or not calculating a subnet mask in IPv6 is different than calculating a subnet mask in IPv4.Continue Reading

• Calculating subnets for IP addresses in IPv6

  Understand how subnetting in IPv6 differs from that of IPv4 and what you need to do in order to calculate the subnet of an IP address in IP version 6.Continue Reading

• How can I pass the CCNA exam without spending any money?

  Is there any way to pass the CCNA exam without spending any money? Find out from our Cisco certification expert, David Minutella.Continue Reading

• Are there beginner certifications to take before Cisco's CCNA exam?

  Even though Cisco's CCNA certification is a beginner course, if you're new to networking, passing this exam is daunting. Try the starter certifications our Cisco expert suggests in this piece of advice.Continue Reading

• Five steps to a next-gen network transformation plan

  Creating a network transformation plan establishes a solidly outlined plan to get the most out of a service provider's next-generation network investment. Networking expert Tom Nolle presents the essential five steps needed to create a flexible ...Continue Reading

• HTTP error code troubleshooting, Part 3: Disabling IE friendly error messages

  To troubleshoot an HTTP error code, you may need to disable Internet Explorer's friendly error messages. In this tip, learn how to do this and discover the reasons why you may continue to see the same friendly error message.Continue Reading

• Why do Linksys WMP300N wireless cards have three antenna connectors?

  Before you make a larger antenna for your wireless network card, know how the Linksys WMP300N connects to its antenna, and understand why it has three connectors.Continue Reading

• HTTP error code troubleshooting, Part 2: How to use IIS tool WFetch

  You can understand what's causing an HTTP error by looking at the error code, but sometimes that's not enough. In this tip, learn how to use network analysis tool WFetch, from Microsoft's Internet Information Services (IIS) 6.0 Resource Kit, to ...Continue Reading

• LANs vs. WLANs: Which network designs are used for each company size?

  Which network design is easier to implement, LANs or wireless LANs? Our network administration expert explains this and which designs best fit particular functions and areas of your organization.Continue Reading

• MPLS QoS: Implementing the best model for guaranteed service

  Adding Quality of Services (QoS) guarantees for MPLS VPN services using DiffServe is a significant engineering undertaking, but advanced planning will help you choose the right QoS model for the project.Continue Reading

• How can I block my competitor's IP address range from my website?

  Are you looking for free network tools to find an IP address range? This advice from our security expert shows you whois tools available to you and then explains how to block these ranges from viewing your Web resources, in this expert response.Continue Reading

• Controlling network access by MAC address restriction on wired networks

  If you've used MAC address restriction to control your network access on your wireless router, can you extend this to your wired network? Our security expert explains in this response.Continue Reading

• Why are patch panels required for cabling networks?

  When cabling networks, you may wonder why it's a requirement to have patch panels and why they aren't connected to switches. This expert response explains why and how they're used in a rack with multiple switches and ports.Continue Reading

• The TPM chip: An unexploited resource for network security

  The TPM chip developed by the Trusted Computing Group is installed in most new desktops, laptops and servers. It can be used to strengthen user login authentication, protect against unauthorized software modification, and fully encrypt hard disks ...Continue Reading

• HTTP error code troubleshooting, Part 1: HTTP status codes defined

  To troubleshoot HTTP error codes, you must first understand HTTP status codes. Any time a client issues an HTTP request to a Web server, the server returns a response code. In this tip, learn the 100, 200, 300, 400 and 500 Series response status ...Continue Reading

• On a full-duplex T1 circuit, what's the bandwidth speed in both directions?

  Find out if a full-duplex T1 circuit splits its bandwidth between the TX and RX directions.Continue Reading

• IEEE 802.11w protects wireless LAN management frames

  The IEEE 802.11w wireless encryption standard builds on the 802.11i framework to protect against subtle attacks on wireless LAN (WLAN) management frames. It will increase the confidence of network managers that applications such as wireless VoIP can...Continue Reading

• What is the role of a network administrator?

  Learn the differences and job duties of network and system administrators in this expert response.Continue Reading

• Simulators for practicing Cisco's CCNP routing and switching exam

  To practice for the CCNP routing and switching exam our Cisco expert, David Minutella, recommends this simulator.Continue Reading

• 3 recession survival steps for telecom service providers

  As the economy settles in for an extended recession, telecom service providers can prepare their businesses to not only survive the global economic downfall, but to pull through in a strengthened position. CIMI Corp. President Tom Nolle offers three...Continue Reading

• How do I set up multiple VLANs on a single switch?

  Learn how set up VLANs on one switch and replicate them throughout the network in this response.Continue Reading

• How can I use VLANs and NAT to get around the need for a static IP address?

  Learn how to use a VLAN and NAT to get around static IP address designation problems.Continue Reading

• What correlation does ping latency have with high server activity?

  Our network administration expert explains which metrics provide visibility into what's going on at peak activity levels in order to optimize network performance in this expert response.Continue Reading

• What is the main advantage of having a Layer 3 switch over a router?

  In this Q&A, our router expert, Sudhanshu Gupta, talks about the advantages of having an L3 switch over a router.Continue Reading

• Properties of Windows Management Instrumentation: Managing Windows networks using scripts, Part 12

  Learn how to display all properties of any Windows Management Instrumentation (WMI) class in this tip on how to manage Windows networks using scripts.Continue Reading

• What's the difference between VPN pass-through and multi-tunneling?

  Learn why multi-tunneling is better than VPN pass-through and how IPsec plays a role from an expert.Continue Reading

• Minimum and maximum Ethernet frame sizes

  In this Q&A, our network administration expert addresses Ethernet frame sizes, as well as minimum and maximum sizes of Ethernet frames that carry IP and ICMP.Continue Reading

• How does IPv6 subnetting work in LAN and VLAN network design?

  Learn the differences between IPv4 and IPv6 addressing and subnetting for local area network (LAN) and virtual LAN (VLAN) design in this expert advice.Continue Reading

• Measure wireless network performance using testing tool iPerf

  In this tip, learn how to measure wireless networking performance with iPerf -- a tool that calculates TCP/UDP, throughput, loss and delay. Eliminate jitter, isolate bottlenecks of traffic, or monitor Wi-Fi or AP performance using this open source ...Continue Reading

• Problem connecting to virtual private network (VPN) through Linksys router

  When your remote worker has problems connecting to your virtual private network (VPN) only when they go through a Linksys router, use these steps to resolve the connection issue.Continue Reading

• Wireless networking problems combining 802.11n and 802.11g APs cause

  Will using both 802.11g and 802.11n access points cause problems with your wireless network? Learn from Wi-Fi expert Lisa Phifer how to ensure peaceful coexistence between old and new clients sharing the same frequency band, in this answer.Continue Reading

• Why haven't I received my CCNA certification? I passed the test.

  Find out who to contact when your CCNA certification hasn't arrived from Cisco.Continue Reading

• Network-to-network VPN gateway configuration for Cisco EzVPN

  Learn how to support network-to-network IPsec VPN topologies using a router as the VPN gateway with Cisco EzVPN.Continue Reading

• How to set up a VLAN on multiple switches

  Learn how to establish a VLAN over multiple routers in this response from a networking expert.Continue Reading

• Can a Layer 3 switch replace a router for WAN connections?

  Learn how to use a Layer 3 switch in place of a router for WANs from a routing expert.Continue Reading

• How can I implement MAC address binding between switches?

  Learn what configuration you need to implement MAC binding across switches in this expert response.Continue Reading

• OSS service delivery platforms: New services launch pads

  Service delivery platforms (SDPs) bring together many OSS/BSS disciplines and provide a unified view of subscriber data, service configuration and device-level information that strengthens every link in the service fulfillment chain.Continue Reading

• Tackling next-gen network OSS/BSS challenges

  Use OSS/BSS to help manage packet-switched, content-driven telecom networks so the right packets reach the right customers, and service providers capture the revenue.Continue Reading

• Why isn't CCNA certification enough to get me hired?

  Learn why CCNA certification won't guarantee you a job and what you can do to secure a position.Continue Reading

• Packet optical: Differing views on network elements

  Packet optical networking solutions may be the biggest new thing for replacing or migrating away from TDM-based SONET/SDH optical networks. Telecom service providers are looking at both single and multiple network element solutions, depending on ...Continue Reading

• In IPv4, do private address ranges have a default subnet mask?

  In this expert response, Silvia Hagen explains the relationship between private IP address range and default subnet masks. She also informs us about new address types coming up in IPv6 that will make subnetting and addressing easier.Continue Reading

• More remote scripting tricks: Managing Windows networks using scripts, Part 11

  Learn a remote scripting trick and how to use Windows Management Instrumentation Command-line (WMIC) to remotely query for local administrators in this tip from the series Managing Windows networks using scripts.Continue Reading

• How to implement VLAN switches across wireless LAN (WLAN) links

  Learn different methods of creating virtual LANs (VLANs) on a wireless LAN (WLAN) in this expert response from Lisa Phifer.Continue Reading

• 802.11s mesh networks

  802.11s mesh technology, currently under development by the IEEE, will bring a number of advances to 802.11 wireless networking.Continue Reading

• What does a QM FSM error signify on a VPN Concentrator?

  Learn how to solve a QM FSM error when working on a LAN-to-LAN VPN from a network security expert.Continue Reading

• Split-tunnel Cisco IPsec VPN gateway with software client

  This article covers the steps of building a Cisco router-based VPN gateway and software client using a split-tunneling traffic model in which only traffic to secured networks is encrypted and all other traffic is forwarded unsecured.Continue Reading

• Full-crypto Cisco IPsec VPN gateway with software client

  Learn how to build an IPsec VPN gateway with a Cisco router and software client using a full-crypto traffic model in which all traffic is either encrypted or processed by an internal firewall.Continue Reading

• IPsec VPN router configuration: The ISAKMP policy

  As part of building an IPsec VPN gateway on a Cisco router, readers will learn how to implement ISAKMP policies using IKE to ensure secure VPN configuration.Continue Reading

• VPN gateway router configuration using transform sets

  Implementing IPsec VPN gateways on Cisco routers involves a number of different configuration elements. In addition to the ISAKMP and IKE configuration, transform set definitions are part of configuring gateways that will support Cisco software VPN ...Continue Reading

• 3 reasons to speed legacy to next-gen network migration

  It's about revenue flow. Telecom providers have three good reasons--customer demand, economics and network equipment--to speed their transition from legacy to next-gen telecom networks. Here's how to go about it.Continue Reading

• VPN gateway router configuration using static and dynamic crypto maps

  In addition to the ISAKMP/IKE configuration and transform set definitions, static and dynamic crypto maps are part of configuring gateways that will support Cisco software VPN client connections.Continue Reading

• How does WiMAX compare to other wireless broadband services?

  Learn about WiMAX and similar WAN technologies, such as 3g, in an expert response from Lisa Phifer.Continue Reading

• IPsec VPN authentication: Generating and exchanging pre-shared keys

  A crucial part of implementing VPNs using Cisco routers is using ISAKMP policies. This article explains the final step of IKE and ISAKMP setup, authentication key configuration.Continue Reading

• IPsec VPN connection models: Site-to-site and client-to-site

  This article explains the two basic forms of IPsec VPN connection models: site-to-site and client-to-site topologies.Continue Reading

• IPsec protocol details for implementing VPNs

  This article provides IPsec protocol background and details for those implementing IPsec VPN gateways using Cisco routers. Learn about Internet Security Association and Key Management Protocol (ISAKMP) and Internet Key Exchange (IKE) in preparation ...Continue Reading