Ask the Experts

Ask the Experts

Network Infrastructure

• Will NFV standards address orchestration in the near future?

  NFV standards for orchestration are affected by the number of standards groups and service providers' individual approaches, says SDN expert Lee Doyle.  Continue Reading

• NFV vs. VNF: What's the difference?

  NFV versus VNF: SDN engineer Darien Hirotsu explains the differences between network functions virtualization and virtual network functions.  Continue Reading

• Is satellite connectivity a realistic option for WANs?

  What you should know about satellite connectivity, satellite internet, and the costs and benefits of universally available links.  Continue Reading

• What are some ways to reduce IT maintenance costs?

  Enterprises spend millions of dollars each year on IT maintenance, service and support. But there are steps you can take to whittle those costs down.  Continue Reading

• What is the difference between bit rate and baud rate?

  Learn how to understand the difference between bit rate and baud rate in this expert answer.  Continue Reading

• Is fabric necessary for network virtualization overlay?

  A fabric topology may become necessary at some point, but for now, you can get away without one for your SDN overlay.  Continue Reading

• What are the WLAN benefits of 802.11ac vs. 802.11n?

  In analyzing wireless 802.11ac versus 802.11n, our expert says the advantages of 802.11ac are many, but the engineering has to be spot on.  Continue Reading

• What is the status of OPNFV?

  Implementing NFV remains a daunting task, but Open Platform for NFV offers a path forward. Our expert explains where the open source platform stands today and where it's headed.  Continue Reading

• What's the best way to handle end-of-sale devices on your network?

  A majority of organizations have end-of-sale and end-of-life devices on their networks. What's the best way to ensure your equipment is up to date?  Continue Reading

• Which SDN protocol should I use?

  At the dawn of software-defined networking, there was one SDN protocol: OpenFlow. Today, users can select from a growing number of options.  Continue Reading

• Container networking: How does Docker relate to SDN?

  Networking expert John Burke tackles container networking in this edition of Ask the Expert, explaining how a Docker container relates to SDN.  Continue Reading

• How can SDN and NFV change the telecom central office?

  SDN engineer Darien Hirotsu discusses the benefits of the Central Office Re-architected as Datacenter concept for the telecom central office.  Continue Reading

• What's involved with global ISP Internet breakout?

  An expert explains how to achieve global Internet breakout connections and gives examples of different connection options.  Continue Reading

• How does the enterprise benefit from IP network transformation?

  An expert explains the benefits and challenges of migrating services from a traditional public-switched telephone network to IP.  Continue Reading

• What is generic Ethernet access?

  Generic Ethernet access is a new carrier service rolling out in the United Kingdom. Is this a technology that can work for you?  Continue Reading

• SDN and network virtualization: How do they work together?

  There are different ways to implement network virtualization in a software-defined network. Jim Meztler explains network virtualization and SDN, and how the two can work together.  Continue Reading

• Types of link-state advertisements (LSAs) used in Open Shortest Path First (OSPF)

  John Burke explains different types of link-state advertisements (LSAs) that would be used for Open Shortest Path First (OSPF).  Continue Reading

• What is 'open' SDN?

  Author Chuck Black explains what 'open' means for SDN, and considers open SDN controllers, protocols and APIs.  Continue Reading

• Is passive optical networking good for enterprises?

  An information systems engineer explains passive optical networking and how it can help an enterprise reduce costs.  Continue Reading

• What separates white-box software from bare-metal switches?

  Network administrators can choose between white-box software and bare-metal hardware and receive the same performance.  Continue Reading

• Are there alternatives to the OpenFlow protocol?

  Jason Edelman explains OpenFlow protocol alternatives and what's important in determining which southbound protocol will work for you.  Continue Reading

• Should I use the OpenFlow protocol in software-defined networks?

  The OpenFlow protocol isn't required for SDN, although the Open Network Foundation recommends it, which means networking vendors have options.  Continue Reading

• Why do I need SDN technology?

  SDN is valuable, but uses extend to other parts of the network for increased network flexibility, dynamic traffic flow, decreased latency and QoS.  Continue Reading

• SDN, network virtualization: Are they the same?

  Despite differences, SDN and network virtualization share common elements to direct network resources to VMs and segment or consolidate networks.  Continue Reading

• What are the benefits of IPv6 in SDN and network virtualization?

  One of the benefits of IPv6 is that it makes software defined networking and network virtualization scale easily, IPv6 expert Ciprian Popoviciu says.  Continue Reading

• When military radar causes fixed broadband wireless interference

  Military radar may cause fixed broadband wireless interference. This expert tip explains tests and ideas to check if this is the case and how to address this interference.  Continue Reading

• Expert advice for file server troubleshooting

  Network administration expert, Lindi Horton answers a query regarding file server troubleshooting. She explains potential reasons for file server issues, and things to check to solve the problem.  Continue Reading

• Packet vs. circuit switching data networks: An expert explains the differences

  Network administration expert, Lindi Horton answers a query regarding packet vs. circuit switching in regards to data networks by using an analogy to help explain the concept of both.  Continue Reading

• Expert tips to solve port 3389 issues when end users gets blocked

  Enterprise security expert, Michael Gregg answers a question regarding port 3389 issues when a user tries to open port 3389 RDP on their router to work from home, but hits a roadblock when the ISP blocks the port.  Continue Reading

• Wireless access for mall kiosk

  Wireless expert Lisa Phifer answers a question on how to connect wired networked devices to a mall's wireless access.  Continue Reading

• Linking an unmanaged switch and DHCP server

  Unmanaged Linksys switches don't know where to send BootP and DHCP requests. Find out what to do to fix the problem of unmanaged switches and DHCP servers.  Continue Reading

• Configuring VLANs on a Cisco Catalyst 3750 and Catalyst 2950 together

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• How does User-based Rate Limiting (UBRL) do if I have oversubscribed a port or switch?

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• Frame relay vs. ATM networks: What's the difference?

  Want to know the difference between frame relay and ATM networks? Find out in this expert response.  Continue Reading

• Why is the 802.11g Wi-Fi throughput speed on my smartphone slow?

  I recently purchased a smartphone with Wi-Fi (802.11g) but found video over Wi-Fi to be pretty choppy. I checked SpeedTest and I don't get anywhere near 54 Mbps when connected to Wi-Fi. Why not?  Continue Reading

• How do I set the Web page default on a network of computers without setting them all individually?

  Learn how to set a default for a network of computers if a group policy isn't working. Instead of setting each machine manually, learn what else you can do.  Continue Reading

• How many wireless base stations can connect to 802.11g access points?

  Our wireless networking expert, Lisa Phifer, talks about the information you need in order to support additional clients on 802.11g access points (APs), in this advice.  Continue Reading

• What is network infrastructure and what is a hybrid network?

  Learn specific networking terms to help setup and choose a specific type of network infrastructure from a single proprietary company or a hybrid of vendors, from our expert Tessa Parmenter.  Continue Reading

• What preventative maintenance procedures for network equipment exist?

  Learn the best practices for monitoring and maintaining your Cisco IP equipment based on potential fault and performance management best practices, from our expert Lindi Horton.  Continue Reading

• Do I have to disable DHCP on my router to create a DHCP server?

  Learn how to turn off DHCP properly in order to use a DHCP server that is configured on a Windows server, and ensure that your routers are not acting as DHCP servers, from our expert Lindi Horton.  Continue Reading

• Is there VLAN software recommend for Realtek NICs?

  Find out which VLAN (virtual local area network) software recommendations and device drivers are the best solutions for your Realtek NIC, from our expert, Lindi Horton.  Continue Reading

• How can I replicate the services of Active Directory (AD) in ADC?

  Learn how to replicate AD services in ADC (Active Directory Controller) by creating policy replication agreements between two or more servers, from our expert.  Continue Reading

• How server virtualization improves efficiency in a client-server model

  How can server virtualization benefit a business in a client-server model? Our network administration expert explains how virtualization can optimize productivity in this expert response.  Continue Reading

• What is IP?

  Learn fundamental networking basics in this expert response defining the acronym 'IP.'  Continue Reading

• Why would a computer show drive letters for discs that don't exist?

  If a computer shows drive letters for removable discs that aren't physically connected to it when no hard disk partitioning has been done, could a virus be responsible? Our network administration expert explains.  Continue Reading

• How to find an SSID and identify neighboring WLANs

  Wireless network expert Lisa Phifer explains what an SSID is and how to identify and differentiate between neighboring WLAN identifiers in this expert 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

• 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

• 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 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

• 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

• 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

• 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

• 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

• 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 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

• 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 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

• 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

• 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

• How can I prevent collisions on my network?

  Learn about network collisions and how to prevent them with networking expert Chris Partsenidis.  Continue Reading

• What is a logical network? How do you improve one?

  Learn what logical and physical networks are and how to improve them, in this expert response with networking fundamentals expert, Chris Partsenidis.  Continue Reading

• How can I configure 10 VLANs with 5 unmanaged switches?

  Given a Cisco Layer 3 (L3) switch and 5 unmanaged switches, learn how to create 10 VLANs from our routing and switching expert, Sudhanshu Gupta.  Continue Reading

• How do I configure two leased lines in one router?

  Our routing and switching expert explains how to configure two leased lines in one router, in this Ask the Expert answer.  Continue Reading

• Why are IPv6's IP addresses in hexadecimal formatting?

  Why would IPv6 use hexadecimal formatting if it's so user unfriendly, and what sort of workarounds are there to make IP addressing easier? Find out in this expert answer.  Continue Reading

• Understanding VLAN implementation and IP address assignment

  Learn how to create and configure a VLAN in this response from a network administration expert  Continue Reading

• What is NAT, and how do I know if it's taking place on my network?

  In this Q&A, our expert explains the basics of NAT (Network Address Translation), where it occurs, and what it does.  Continue Reading

• Differences between Internet Connection Sharing (ICS) and bridging

  Learn the difference between Internet Connection Sharing (ICS) and bridging between two NIC cards from networking fundamentals expert Chris Partsenidis.  Continue Reading

• Why IPv4 and IPv6 don't do fragment reassembly in routers

  Learn why IPv4 does not do fragment reassembly at the next router and why this is even more important in IPv6.  Continue Reading

• Is time-to-live (TTL) thrown out in IPv6?

  Why is there time-to-live (TTL) in IPv4 but not in IPv6? Find out in this expert response.  Continue Reading

• LAN network design considerations

  Look at these LAN network design considerations from network administration expert Lindi Horton.  Continue Reading

• What is the maximum length of attenuation for twisted pair cables?

  Find out the industry standards for twisted pair cable length in this response from network infrastructure expert Carrie Higbie.  Continue Reading

• How do IP addresses work on Layer 2 switches?

  Learn how IP addresses work on Layer 2 switches from our networking fundamentals expert.  Continue Reading

• How do you design networks to allow for future growth?

  Use these steps to allow for enough future growth in your network design.  Continue Reading

• What is the procedure for assigning network addresses?

  Learn how to assign network addresses, and understand the difference between assigning IP addresses and assigning network addresses in this response.  Continue Reading

• What is interVLAN routing?

  Learn what interVLAN routing is in this Ask the Expert with routing expert Sudhanshu Gupta.  Continue Reading

• Why was IPv6 developed, and what issues does IPv4 have?

  Learn what issues cannot be rectified using IPv4 and why IPv6 was developed, in this Ask the Expert.  Continue Reading

• Can you convert a Layer 3 switch to Layer 2?

  See how a Layer 3 switch can convert to a Layer 2 switch, in this expert response.  Continue Reading

• What is FEC in MPLS?

  Learn what Forwarding Equivalence Class (FEC) is and how it works with Multiprotocol Label Switching (MPLS).  Continue Reading

• How do you check if TCP/IP is installed on the system?

  Understand the TCP/IP stack and how to check if it is installed on your system in this networking fundamentals expert response.  Continue Reading

• What protocol works on all layers of OSI?

  Learn what protocol, if any, works on all layers of OSI in this expert answer.  Continue Reading

• Do sandstorms, too much heat, and strong winds affect Wi-Fi connections?

  How much does weather affect Wi-Fi? Wireless networking expert Lisa Phifer explains how sandstorms, too much heat and strong winds might affect your connection in this Q&A.  Continue Reading

• How can I define the layered approach to protocols?

  Learn what the network security advantages are in the layered approach to protocols and how to define the layered approach protocol, in this Q&A with Michael Gregg.  Continue Reading

• What are the routing differences between IPv4 and IPv6?

  Between IPv4 and IPv6, find out how routing differs, in this Q&A with Silvia Hagen.  Continue Reading

• How does a Layer 3 switch work in a network?

  Learn how a Layer 3 switch works in a network, in this Q&A with routing and switching expert Sudhanshu Gupta.  Continue Reading

• How do I connect my VLANs to the Internet using NAT and the appropriately configured ACL?

  Confused about using NAT and configuring ACL? Learn how to connect your VLANs to the Internet over a router with sub-interfaces already defined.  Continue Reading

• What is the advantage of frame relay over leased lines?

  Learn about data transmission over leased lines in this expert response about frame relay.  Continue Reading

• Can you hook a Cisco IP phone to a wireless access point connection?

  Find out if you can hook a Cisco IP phone to a wireless access point connection in this Q&A with Carrie Higbie.  Continue Reading

• What causes my overseas VPN connection to slow during the day?

  Learn what slows connectivity for a VPN overseas during particular times of day, in this Q&A with VPN expert Sampath Ramaswami.  Continue Reading

• What equipment do I use to connect two LANs in different cities? What are the steps?

  How do you connect two LANS from different cities? VPN expert Sampath Ramaswami notes the steps to be taken, in this Q&A.  Continue Reading

• Can a machine with a single DNS name have multiple addresses?

  Can a machine with a single DNS name have multiple addresses? Learn from networking fundamentals expert Chris Partsenidis in this expert response.  Continue Reading

• When do you use a straight-through patch cable, and when do you use a crossover cable?

  Learn when to use a straight-through patch cable and when to use a crossover cable in this Q&A with infrastructure expert Carrie Higbie.  Continue Reading

• What is the step-by-step process to ping a host on two hosts using a router?

  Learn how to ping a host on two hosts using a router in this expert response by Sudhanshu Gupta.  Continue Reading

• Is there any private/public IP address range in IPv6?

  Learn about private and public IP address ranges in IPv6 in this expert response by Silvia Hagen.  Continue Reading

• Can more than one computer on a LAN function as a server?

  Network administration expert Lindi Horton answers whether or not more than one computer on a LAN can function as a server.  Continue Reading

• Where can I find a good practice lab for Aruba mobility controller, switches and access points?

  Find a good practice lab for Aruba mobility controller, switches and access points in this expert response by Lisa Phifer.  Continue Reading

• What is the difference between a patch panel and a switch?

  Routing and switching expert Sudhanshu Gupta explains the use of a patch panel and how it differs from a switch in this response.  Continue Reading