Problem solve
Get help with specific problems with your technologies, process and projects.
Problem solve
Get help with specific problems with your technologies, process and projects.
What is the difference between an Ethernet interface on a router and sub-interface on a router?
What are the differences between PVC, riser and plenum rated cables?
What is CDP in router configuration?
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Can you explain the ICMP ping test?
DHCP Failover
Learn about some of the advances in DHCP Failover protocol. Continue Reading
How can we say TCP is a reliable protocol?
How can I find a good job if I have my CCNA but now experience with Cisco routers?
How are the CCNA test lab questions graded?
On the CCNA test lab questions, could using the short version of the commands make the difference between passing and failing? Or are the labs graded on the end result?Continue Reading
Why can't I access my company's VPN?
How do I set up a VPN to connect seven offices and the headquarters?
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Network administrator security policies
Some security policy elements that are specific to network administrators.Continue Reading
Introduction to IP multicast
A look at the basics of multicasting.Continue Reading
What are the advantages of 10 Gigabit Ethernet?
Learn about the advantages of using 10 Gigabit Ethernet for your corporate network, in this Ask the Expert response.Continue Reading
My firewall keeps reporting intrusion attempts described as "DCE endpoint resolution." What's going
MPLS and CE redundancy
Robbie Harrell reviews the hidden concerns you need to be aware of when making a decision regarding CE-PE resiliency options.Continue Reading
Can you assign an IP address ending in .0 or .255?
Learn how to assign an IP address ending in .0 or .255 from networking fundamentals expert Chris Partsenidis in this Q&A.Continue Reading
How do I connect my managed switch to a patch panel?
How do I measure the performance of a Linux router?
How to measure the performance of a Linux router.Continue Reading
What is the difference between a network switch and a KVM switch?
What is the difference between a network switch and a KVM switch?Continue Reading
Configuring HSRP and VRRP on Cisco routers
A brief overview of HSRP and VRRP and their configuration on Cisco routers.Continue Reading
If we could redesign IP to use the six byte MAC as IP addresses instead of the current 32 bit addres
Minimizing Layer 2 problems
Understanding the fundamentals of Spanning Tree Protocol.Continue Reading
VoIP analysis
Best-effort delivery of packets is not good enough for VoIP, so the network must be stable and predictable to provide quality comparable to circuit-switched telephone networks.Continue Reading
Choosing a wireless architecture
This article discusses important issues in choosing a wireless architecture and describes products from a small sampling of vendors.Continue Reading
Configuring MPLS experimental bits
How to configure QoS using experimental bits.Continue Reading
Router Expert: Conducting a network inventory, part 1
Peforming a network inventory is the first step to an audit. It allows you to build a complete picture of your environment and will reveal inconsistencies that should be resolved.Continue Reading
Auto-MDIX
How Auto-MDIX can solve the cross-over cable conundrum.Continue Reading
OSPF - Juniper vs. Cisco
A look at the different ways OSPF standards are implemented on Juniper and Cisco routers.Continue Reading
Network administrator documentation
Networking documentation is often missing a critical component: the Why.Continue Reading
The 10 traits of effective security
Regardless of company size and industry, the most effective information security programs have several essential components in common. Read about the most crucial ones.Continue Reading
When a node connects to a network, does it send a neighbor solicitation message and router solicitat
How can I assign fixed bandwidth to individual users/IP addresses by using CISCO 1711 router?
Intranet tunneling
Using tunnels to segment private networks on your intranet.Continue Reading
How can I enable my desktop and my laptop to share files?
MPLS: Experimental bits and QoS
MPLS experimental bits are used to provide QoS capabilities by utilizing the bits set in the MPLS labels.Continue Reading
Layer 2 VPN scalability
A look at the limitations of layer 2 VPN scalability.Continue Reading
How do I connect to the console and AUX port of my router?
How do I connect to the console and AUX port of my router?Continue Reading
How can I determine how many kbps my network is operating on?
Should I try for the CCNA certification or the CCDA certification?
What is a network segment? Is a network segment the same as an Ethernet segment?
How does the MAC address affect routers/switches?
Learn what MAC addresses have to do with network routers and switches from our routing and switching expert.Continue Reading
WAN redundancy options
A short list of four of the best ways to provide WAN redundancy.Continue Reading
Is there any easy way to measure EMF/EMI interactions?
One of my computers cannot communicate with the rest of the network and I can't figure out why.
Can you explain the concept of Quality of Service?
IP telephony development tools
A look at some tools for developing IP telephony applications.Continue Reading
How can one test VoIP functionality with their existing PBX or Key system?
Can you explain MER Mac encapsulation routing?
How do intrusion detection systems work?
Can you help me put together a WLAN proposal?
What's your information security gap?
Many businesses are developing an information security program -- a formal, structured program that helps ensure the security of business assets and operations.Continue Reading
Wireless for redundancy
Implementing a wireless network is usually done for the sake of mobility, but why not consider it for redundancy?Continue Reading
Simplifying and standardizing your device configurations
Simplifying and standardizing your device configurations.Continue Reading
What is the difference between TCP/IP and IP protocol?
How should I prepare for the CCNA exam?
VPLS, a new Layer 2 MPLS VPN technology
A new Layer 2 MPLS VPN technology that provides similar reliablity and QoS as MPLS VPN, but in a more simplified way. But beware, it does have it's limitations.Continue Reading
Instant messaging service blockers
A look at ways to monitor and block IM traffic.Continue Reading
Using multiple routing protocols
A discussion of IGP and EGP and ways in which they should be implemented together.Continue Reading
Routing First-Step: IP version 4 and IP version 6
Routing and Internet addressing are two important concepts involved in networking. Routing First-Step covers the basics of routing in clear, easy-to-understand language.Continue Reading
Locking down wireless hot spots with 802.1X
Hot spots can increase business productivity, but careless use can lead to corporate resource compromise.Continue Reading
Is it possible to broadcast a message to all my network computers using Server 2003?
Can CAT 6 be used to connect two switches at a distance of 550 meters?
What type of security is associated with each level of the OSI model?
Can you explain many-to-one address translation?
Protocols, Lesson 7: Subnet masks and their effect
Understand the different effects a subnet mask can have.Continue Reading
Protocols, Lesson 9: Subnet routing and communications
Lesson 9 in our protocol series covers the communications side of subnetting.Continue Reading
Troubleshooting firewalls
How to troubleshoot your firewall's settings when it is preventing a client or server connection.Continue Reading
Router Expert: Implementing IOS CLI menus
CLI menus enable network administrators to build overlay menu-driven interfaces for accessing EXEC shell commands.Continue Reading
Why do I keep losing my network connection?
MPLS - Preparing an RFP (Dos and Don'ts)
A look at the things to include in an RFP, a request for proposal for VPN service.Continue Reading
Password checking
Some programs to test your password integrity.Continue Reading
Connecting two hosts with the same IP address but different subnet masks
Is it possible to communicate two hosts with the same IP address but different subnet mask without adding a router?Continue Reading
Settings for RTS Threshold and Fragmentation Threshold
Preventing Layer 2 security threats
Layer 2 switched environments, typically found in enterprise customer wiring closets, can be easy targets for network security attacks.Continue Reading
OSI model: List of some attacks
What is the difference between symmetric and asymmetric bandwidth?
What are the elements of creating a wireless connection between two buildings?
How can I get a better understanding of routing and switching and all the Layer 3 protocols?
How do I connect two wired LAN networks with a wireless link?
What is the difference between a logical network design and a physical network design?
I cannot establish a VPN connection the error I get is 'failure by initializing of IPsec link.' Can
Top 5 ways to make your network more secure
Some things to get you thinking about what kind of budget you will need to improve your network's security.Continue Reading
How can I reduce the number of broadcasts on my network?
Is there any downside to PoE?
Is there any downside to PoE?Continue Reading
Are there any inherent security problems with UDP?
Router Expert: Configuring IOS terminal services
This tip covers IOS configuration of a Cisco router as a terminal server providing direct asynchronous access to other Cisco routers, along with modem access for dial-out services.Continue Reading
What is the maximum number of routers that can be recorded in an IP datagram if the timestamp option
What's the difference between packet sniffers and protocol analyzers?
Learn the difference between packet sniffers and protocol analyzers in this Ask the Expert response with our networking fundamentals expert.Continue Reading
How do I block DHCP requests and replies from different segments of my network?
MPLS - Label Distribution Protocol
A look at some of the details of Label Distribution Protocol (LDP) and how it works in an MPLS VPN.Continue Reading
How VoIP is changing telecommunications for businesses
A look at some alternatives to VoIP and traditional PBXs.Continue Reading
What are the main challenges facing DNS management today?
What are the main challenges facing DNS management today?Continue Reading
Run your VoIP calls over a VPN for enhanced security
A look at using a VPN to enhance VoIP security.Continue Reading
How is the DNS market evolving to meet today's challenges?
How is the DNS market evolving to meet today's challenges?Continue Reading
Can you please explain how a DHCP server allocates IP addresses dynamically?
Learn how DHCP works in this Ask the Expert response from our networking fundamentals expert, Chris Partsenidis.Continue Reading
Core, Distribution and Access
A look at a possible logical architecture for routing and switching and how to covert it from logical to physical.Continue Reading
Top 10 'show' commands
A list of the top ten 'show' commands.Continue Reading
How do I connect our seven offices to a VPN using DSL lines?
Where to connect a switch -- Patch panel versus ports around the office
Is it possible to connect my switch directly to my patch panel rather than connecting the switch to the various ports around my office?Continue Reading
The difference between an access point and a bridge