Ask the Experts
Ask the Experts
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Intrusion detection vs. intrusion prevention
Our expert, Puneet Mehta, tells us what the key difference is between intrusion detection and intrusion prevention, in this expert response. Continue Reading
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What are the fundamental principles of CDMA?
In this Q&A, our expert, Lindi Horton gives us an explanation of what CDMA is and what some of its fundamental principles are. Continue Reading
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Half duplex vs. full duplex Ethernet 10BASE-T topologies
Ever wonder why half duplex Ethernet 10BASE-T topologies have a slower data transmission rate than full duplex Ethernet 10BASE-Ttopologies? Find out in this expert response by Lindi Horton. Continue Reading
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System engineer vs. network administrator
Our Cisco certifications expert, David Minutella, answers what the responsibilities of a system engineer and network administrator are and what makes the two jobs different. Continue Reading
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What is a seamless router?
In this expert response, Sudhanshu Gupta gives us a quick history lesson in routing when he answers the question "what is meant by the term 'seamless router'?" Continue Reading
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Is it possible to use a Cisco 2950 switch as a DHCP relay?
In this response, our routing and switching expert, Sudhanshu Gupta, provides a table of commands to enable a Cisco 2950 switch DHCP functionality. Continue Reading
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What to do when your server goes down
When a server goes down at a particular time every night without the prompt of a virus, our expert, Puneet Mehta, can tell you what the problem is and what you can do to avoid it. Continue Reading
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The difference between RIP, IGRP and EIGRP
Our expert, Sudhanshu Gupta, goes over the differences between RIP, IGRP and EIGRP, in this explanation. Continue Reading
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Differences between adapters and modems
Our expert, Sudhanshu Gupta answers what it means when a router says the connection has been resent by the remote host and what the difference is between a WAN adapter and a modem. Continue Reading
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The most commonly used network operating system
In this Q&A, Lindi Horton answers the question "What network operating system is more currently and commonly used?" Continue Reading
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Configuring managed and unmanaged switches
In this Q&A, Sudhanshu Gupta answers which cable to use with managed and unmanaged switches. Continue Reading
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How close are Cisco practice exams to the actual test?
David Minutella explains here how close the CCNA practice tests are to the real thing and mentions a few to check out. Continue Reading
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Can you distinguish between 802.11n and 802.11g?
In this response, Mike Puglia describes the difference between 802.11n and 802.11g. Continue Reading
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What is a cause of crosstalk in UTP cables?
Higbie provides a useful link to understand crosstalk in UTP cables. Continue Reading
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Multicasting on a wireless network
In this response, Phifer discusses multicasting on a wireless network. Continue Reading
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Wireless LAN setup for hotels
Phifer discusses the requirements for WLAN setups in hotels. Continue Reading
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Differences between open-source and commercial IDS
Here, Michael Gregg explains the differences between open-source and a commercial IDS. Continue Reading
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Wi-Fi hot spot plan or 3G wireless data service
Should you use a Wi-Fi hot spot plan or a 3G wireless data service? Continue Reading
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What is the purpose of Wi-Fi ad-hoc mode?
Our wireless networking expert, Lisa Phifer, defines and explains Wi-Fi ad-hoc mode and its pros and cons, in this Ask the Expert response. Continue Reading
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How I can get hands-on routing experience via the Internet?
Discover how to gain routing experience using online simulators. Continue Reading
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What are the fundamentals of ATM and ISDN?
Lisa Phifer explains the fundamentals of ATM and ISDN and why they are used. Continue Reading
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SMB wireless LAN setup
Advice for setting up a WLAN for a SMB. Continue Reading
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Is there an industry standard for monitoring network/device availability?
Is there an industry standard for monitoring network/device availability? Continue Reading
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Why does my network go down every night?
Our networking fundamentals expert, Chris Partsenidis, explains why a network server might go down at a certain time every night, in this expert response. Continue Reading
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Why is the cable supporting my LAN experiencing abnormal attenuation?
Why is the cable supporting my LAN experiencing abnormal attenuation? Continue Reading
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Is there really a big difference between cheap, residential-grade wireless APs and expensive, busine
Is there really a big difference between cheap, residential-grade wireless APs and expensive, business-grade wireless APs? Continue Reading
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Can you help me understand the differences between WPA2 and Cisco's LEAP security?
Expert Lisa Phifer explains the differences between WPA2 and Cisco's LEAP security and takes a look at stronger EAP types that can be used with 802.1X. Continue Reading
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How do I connect my printer to the network without Ethernet cables?
How do I connect my printer to the network without Ethernet cables? Continue Reading
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What is the difference between an IT audit and SOX audit?
What is the difference between an IT audit and SOX audit? Continue Reading
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What does the future hold for Power over Ethernet (PoE)?
What does the future hold for Power over Ethernet (PoE)? Find out from our network infrastructure and developing technologies guru, Carrie Higbie, in this Ask the Expert response. Continue Reading
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Can you help with an Active Directory authentication problem?
Can you help with an Active Directory authentication problem? Continue Reading
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Is there any difference in regard to QoS between IPv4 and IPv6?
Is there any difference in regard to QoS between IPv4 and IPv6? Continue Reading
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What is the future of thin access points relative to wireless network security?
What is the future of thin access points relative to wireless network security? Continue Reading
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What are the advantages of a KVM switch over a Layer 2 or Layer 3 switch?
What are the advantages of a KVM switch over a Layer 2 or Layer 3 switch? Continue Reading
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How can I reduce interference issues when installing Cat 5e and 6 cable?
How can I reduce interference issues when installing Cat 5e and 6 cable? Continue Reading
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What is a star bus network?
Learn from our network infrastructure and project management expert what a star bus network is and how to design one. Continue Reading
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How do I specify a network connection in Windows XP?
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What is the difference between a network analyzer and a protocol analyzer?
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What cert is better to start out with, the MCSE or CCNA?
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What causes a TCP SYN-attack?
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Is it possible to connect to a wireless hotspot without getting an IP address?
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Why do we need the MAC address if all Ethernet connections are done via IP address?
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What do I need to do to achieve the CCAI?
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What is difference between a WINS server and a DNS server?
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Can I have two Internet connections -- one the VPN and one not?
Is it possible to have two connections to the internet running simultaneously, one running a VPN and one not? If so, how do you determine which connection a given user session will use? I am running XP. Continue Reading
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Establishing communication between two networks via switches
I have two 3Com layer 3 switches (4924) connecting to two separate networks in a building. How do I configure these switches so that the communication can be established between the two networks?
These two networks are on the first and second ... Continue Reading
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How do I open port 177 on my router so that other clients can get a GUI display of my server remotel
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User acceptance test plan for 1000-branch WAN
My vendor has asked me to prepare a user acceptance test plan for a WAN of 1000 branches, which have leased line and ISDN connectivity. What are the specific parameters I should look for at each branch connection? The vendor has just specified ping ... Continue Reading
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What are intusion detection and intrusion prevention and how do they work?
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What are the system requirements for connecting elevators in a high-rise building via a wireless net
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What's the difference between a network assessment and an audit?
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What certification better compliments the MCSE: CCNA or RHCE?
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How do I set up two or more wireless adapters on the same computer to work together?
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How do you get five switches to talk without using a routing protocol?
I want to add five catalyst 3550 IOS switches to a single 4506 Cisco router so that each switch will have its own subnet. 192.168.10.0, 192.168.11.0, etc.. how do you get all five switches to talk without using an routing protocol like OSPF or RIP ... Continue Reading
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Why can I connect to or ping some computers via my Cisco VPN connection but not others?
Why can I connect to or ping some computers via my Cisco VPN connection but not others? I use Remote Desktop Connection to connect to various computers on our corporate network (Windows XP PRO on all machines and each one has been allowed to receive... Continue Reading
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How can I increase bandwidth at my Internet cafe?
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Placement of the firewall
In this expert response, Puneet Mehta tells us where the placement of the firewall should be architecturally. Continue Reading
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How do I remove Trojan viruses that have infected my network?
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Which transmission media are the most secure and the least secure?
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Where are the best networking jobs for a CCNA?
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Security risks of firewalls and VPNs
What are the key security risks and considerations to adopt firewall/VPN technology? Continue Reading
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How to protect your network from broadcast and multicast storms
What methods are available to protect a network from broadcast and multicast storms? Continue Reading
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Security of each level of the OSI model
What kind of security is associated with each level of the OSI model? Continue Reading
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Advice on making the transition from network engineering to network security
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Can I use my wireless router to create a workgroup between desktops?
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Can you please explain the following, common Ethernet errors?
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What are the advantages and disadvantages for pure IP over IP-enabled solutions?
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What is a network sniffer?
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In a LAN environment, which is better: Token Ring or Ethernet and why?
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What are network collisions and how do they occur? Are they normal?
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What is a collision domain? How does replacing a hub with a switch affect collision?
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Since DNS uses UDP instead of TCP, if a packet is lost, there is no automatic recovery?
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Can I connect two networks, one wired, one wireless, so that I can access the Internet through the s
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How do I configure a switch port to full-duplex and another to auto-sensed from a 24-port Cisco 2950
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What's needed to wirelessly connect two offices 100 feet apart?
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Cannot connect to Internet or local network while on the VPN
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Can you explain the importance of upgrades and patches and what the differences between the two are?
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I need help adding a central MAC address authentication server to our current WLAN.
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How long do I have to finish the CCNP exams before my CCNA runs out?
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What does the term "stackable switches" means?
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How can we improve the performance of our LAN?
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Can SACK and FACK help to minimize packet loss on my WAN?
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How to set up two VLANs with secure Internet access through one router
How can I set up two VLANs with Internet access provided for both via one router, but maintain security between the two (i.e. so nobody from the first VLAN can gain access to the second VLAN and vice versa)? Continue Reading
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What are the differences between physical and logical addressing?
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Having two gateways for a network with two routers
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Is there a difference between Wi-Fi and WiMax?
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How do I block my users from accessing all but a few authorized Web sites?
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How can I fix a corrupt DHCP?
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Configuring main and backup leased lines
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How can I access my Cisco router from the Internet?
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Is VTP a proprietary protocol of Cisco?
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How do I connect to my LAN from the Internet?
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What about using SSL VPN with e-mail clients?
Over the SSL VPN can you reconfigure your email client to send traffic over SSL to the e-mail server? Find out in the Q&A with expert Lisa Phifer. Continue Reading
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What are the basic features of CIDR and what are its advantages and disadvantages compared to IPv6?
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What are advantages to IPV6 regarding mobility and wireless? Are there any?
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Can I connect two computers through Ethernet on a WAN?
Can I connect two computers through Ethernet on a WAN? Continue Reading
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What costs I can expect when designing A LAN? How can I keep costs to a minimum?
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Can you please explain to me how satellite ATM networks work?
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Why is full duplex important to VoiP applications, more so than half duplex?
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How do you interpret a bandwidth utilization graph?