Articles written by Kevin Dooley
The Pros and Cons of VPN Split Tunneling
Should you use VPN split tunneling? Here's what you need to know to decide.
Configuring and Troubleshooting Multicast Protocols
There are two important protocols required to get your network to forward multicast packets. Here's how to configure & troubleshoot them.
What Is Multicast Networking and How Does It Work?
Multicast networking is based on the concept that a single packet can be sent by a server & it will be received by many receivers. Here's…
Special IP Address Ranges and When to Use Them
There are several special IP address ranges that have specific purposes. Network engineer Kevin Dooley explains what they are & the…
![[image] An Introduction to Subnetting](https://www.auvik.com/wp-content/uploads/2020/09/subnetting-primer-1800x1200-1-800x400.png)
An Introduction to Subnetting
You don't need that subnet calculator! Not when you have this handy guide to subnetting using both mask and CIDR notation.
Implementing a Bring Your Own Device Policy In Your Organization
A bring your own device policy is more important than ever since users can bring unsecured personal devices into your office. Here's how…
Why a Zero-Trust Network Is More Desirable—and Achievable—Than Ever
The cybersecurity landscape has changed a lot thanks to the increase in cloud-based services, and zero-trust is now an extremely…
How to Configure Syslog on a Cisco Device
Essentially every modern network device has at least some syslog capabilities. Here's how to configure syslog on Cisco devices.
What Is Syslog and How Does It Work?
Almost every device on a network has a syslog agent you can use to send messages to a central location. Here's how the network-based…
An Introduction to Web Proxies
Web proxies intercept traffic from your systems as they move to others, analyze the packets, and send the data along.
Not All Hacks Are the Same, Plan Your Network Defenses Accordingly
There’s a vast difference between the incredibly sophisticated long-term attacks against high-profile companies and government…
![[image] 3 Switch Features You Should Never Change](https://www.auvik.com/wp-content/uploads/2018/01/network-switch-features-caution-errors-1800x1200-800x400.jpg)
3 Switch Features You Should Never Change
In a handful of recent incidents, I helped clients troubleshoot network problems. The errors turned out to be switch features that were…
![[image] The Why and How of Syncing Clocks on Network Devices](https://www.auvik.com/wp-content/uploads/2017/11/syncing-clocks-NTP-network-time-protocol-1800x1200-800x400.jpg)
The Why and How of Syncing Clocks on Network Devices
One of the keys to effective network management is syncing clocks on all network devices. There are really two ways to do it.
![[image] Simple Network Redundancy: Creating Maximum Availability With Minimum Complexity](https://www.auvik.com/wp-content/uploads/2017/08/simple-network-redundancy-1800x1200-800x400.jpg)
Simple Network Redundancy: Creating Maximum Availability With Minimum Complexity
Complexity is an enemy to reliability. The more complex something is, the harder it is to understand, the greater the chance of human…
![[image] The Benefits of Great Network Configuration Management](https://www.auvik.com/wp-content/uploads/2017/06/network-configuration-management-1800x1200-800x400.jpg)
The Benefits of Great Network Configuration Management
Configuration management is one of those network management topics people often neglect. It’s not very exciting—but it’s incredibly…
The New DR: What To Do When the Internet Is Down
With the move to cloud, disaster recovery has become a special challenge. You now have to worry about what you’ll do if the Internet…
![[image] How to Adjust TCP Window Size to Improve Network Performance](https://www.auvik.com/wp-content/uploads/2017/04/tcp-window-rant-1800x1200-800x400.jpg)
How to Adjust TCP Window Size to Improve Network Performance
Are you seeing poor network performance but with link utilization well below 100%? You might have an issue with your TCP window size.…
Network Basics: An Introduction to SD-WANs
The basic idea of an SD-WAN is to reduce MPLS or other fixed internal WAN circuit costs by shunting some or all of your traffic over…
What to Look for in a Next-Generation Firewall
Considering a next-generation firewall? To help you understand the huge array of available options, engineer Kevin Dooley describes the…
Network Basics: What Is Link Aggregation & How Does It Work?
Link aggregation is a way of bundling a bunch of individual Ethernet links together so they act like a single logical link.
![[image] Implementing ACLs on a Cisco ASA Firewall](https://www.auvik.com/wp-content/uploads/2016/11/acl-cisco-asa-firewalls-1800x1200-800x400.jpg)
Implementing ACLs on a Cisco ASA Firewall
The first line of defense in a network is the access control list (ACL) on the edge firewall. The challenge is that while ACLs can be…
![[image] 6 Common Spanning Tree Mistakes and How to Avoid Them](https://www.auvik.com/wp-content/uploads/2016/10/spanning-tree-mistakes-1800x1200-800x400.jpg)
6 Common Spanning Tree Mistakes and How to Avoid Them
Spanning tree is a Good Thing. It saves you from loops, which will completely shut down your client's network. But it has to be…
Network Documentation Best Practices: What to Create & Why
Everybody agrees network documentation is extremely important, but there tends not to be a lot of agreement on what that documentation…
![[image] Defending Network Infrastructure Against Attack – Part 2](https://www.auvik.com/wp-content/uploads/2016/05/network-infrastructure-security-armored-knights-1800x1200-800x400.jpg)
Defending Network Infrastructure Against Attack – Part 2
Since perfect network security is impossible, your goal is to cover as many of the risk areas as you can with the budget you have. In…
![[image] Defending Network Infrastructure Against Attack – Part 1](https://www.auvik.com/wp-content/uploads/2016/05/network-infrastructure-security-armored-knights-1800x1200-800x400.jpg)
Defending Network Infrastructure Against Attack – Part 1
It’s impossible to create perfect network defenses. But it's not terribly hard or expensive to mount an effective defense. Let’s…
![[image] The 4 Steps to Safely Removing a Network Device](https://www.auvik.com/wp-content/uploads/2016/03/remove-device-shutdown-network-off-1800x1200-800x400.jpg)
The 4 Steps to Safely Removing a Network Device
Unused gear sitting on a network can get very expensive. Get it off there! Here are some general best practices for removing network…
![[image] Managing User Access & Authentication in a Cloud-Hosted Environment](https://www.auvik.com/wp-content/uploads/2016/02/cloud-migration-user-authentication-halt-sign-1800x1200-800x400.jpg)
Managing User Access & Authentication in a Cloud-Hosted Environment
One of the things that becomes more important in a cloud-based application environment is managing user access and authentication. Part 3…
![[image] Configuring an Internet Connection for a Cloud-Hosted Environment](https://www.auvik.com/wp-content/uploads/2016/02/cloud-migration-internet-connection-pipes-1800x1200-800x400.jpg)
Configuring an Internet Connection for a Cloud-Hosted Environment
When a company’s application infrastructure moves to the cloud, a reliable Internet connection becomes mandatory. Unfortunately, the…
![[image] Here’s What a Network Needs After a Cloud Migration](https://www.auvik.com/wp-content/uploads/2016/01/cloud-migration-network-management-goose-1800x1200-800x400.jpg)
Here’s What a Network Needs After a Cloud Migration
In this three-part series, we dig into the implications of a cloud migration and outline some of the network changes that are required to…
![[image] Migrating a Cisco ASA Firewall Configuration From Old Syntax to New](https://www.auvik.com/wp-content/uploads/2015/12/migrating-cisco-asa-firewall-configuration-1800x1200-800x400.jpg)
Migrating a Cisco ASA Firewall Configuration From Old Syntax to New
Cisco made huge changes to the configuration syntax on ASA firewalls starting in version 8.3. Here are some real-world pointers for…
![[image] Google, Zero-Trust Networks, and the Future of Security](https://www.auvik.com/wp-content/uploads/2015/05/zero-trust-network-security-1800x1200-800x400.jpg)
Google, Zero-Trust Networks, and the Future of Security
Back in January, I blogged about zero-trust network architecture as an emerging trend. Zero-trust is now in the news again with Google's…
![[image] How to Configure IPv6 on Cisco Devices](https://www.auvik.com/wp-content/uploads/2015/05/configure-IPv6-network-cables-1800x1200-800x400.jpg)
How to Configure IPv6 on Cisco Devices
In this followup to What Every Network Admin Should Know About IPv6, network engineer Kevin Dooley shows you how to enable and configure…
![[image] What Every Network Admin Should Know About IPv6](https://www.auvik.com/wp-content/uploads/2015/05/ipv6-network-design-admin-2015-1800x1200-800x400.png)
What Every Network Admin Should Know About IPv6
IPv6 comes pre-enabled on a lot of network devices — that’s dangerous unless you’re in control. Here’s what you need to know to…
![[image] An Introduction to Authentication Protocols](https://www.auvik.com/wp-content/uploads/2015/03/authentication-protocols-locks-1800x1200-800x400.jpg)
An Introduction to Authentication Protocols
Centralized authentication improves the manageability & security of your network. In this article, network engineer Kevin Dooley…
![[image] The Secrets to Drawing Effective Network Diagrams](https://www.auvik.com/wp-content/uploads/2017/10/auvik-network-maps-use-case-2017-1800x1200-800x400.png)
The Secrets to Drawing Effective Network Diagrams
Good network diagrams aren't hard to make, yet they're distressingly rare. Even network engineers with years of experience often make…
![[image] 8 Networking Trends to Watch in 2015](https://www.auvik.com/wp-content/uploads/2015/01/networking-trends-2015-auvik-1800x1200-800x400.jpg)
8 Networking Trends to Watch in 2015
What networking trends will we see come to life in 2015? Think security, speed, and cloud.
![[image] How to Explain Highly Technical Ideas to Non-Technical People](https://www.auvik.com/wp-content/uploads/2014/12/technical-ideas-explain-communicate-1800x1200-800x400.jpg)
How to Explain Highly Technical Ideas to Non-Technical People
Executives really appreciate techies who communicate well. It's a rare skill and it translates into promotions and bigger paychecks…
![[image] Stop! Are You About to Make One of These Network Management Mistakes?](https://www.auvik.com/wp-content/uploads/2014/08/network-management-mistakes-danger-sign-1800x1200-800x400.jpg)
Stop! Are You About to Make One of These Network Management Mistakes?
Network pro Kevin Dooley shares the stories of four painful network management mistakes -- and tips on how you can avoid the same goofs.
![[image] How to Troubleshoot Routing Problems](https://www.auvik.com/wp-content/uploads/2014/07/troubleshoot-network-routing-problems-traffic-1800x1200-800x400.jpg)
How to Troubleshoot Routing Problems
Routing problems tend to emerge when you're first setting up a new piece of network equipment, and when something has failed. Usually…
![[image] Verifying Physical Connectivity](https://www.auvik.com/wp-content/uploads/2014/05/network-management-verifying-physical-connectivity-1800x1200-800x400.jpg)
Verifying Physical Connectivity
Many physical troubleshooting exercises come down to the process of swapping out elements until the problem goes away. The key is to…
Out-of-Band Management
Out-of-band management provides a way to log into your network devices without going through the same network through which the data…
![[image] Configuring Syslog and SNMP on a Cisco Device](https://www.auvik.com/wp-content/uploads/2014/04/configuring-syslog-SNMP-Cisco-device-1800x1200-800x400.jpg)
Configuring Syslog and SNMP on a Cisco Device
There are two common ways to get management information about your network devices to a central server: syslog and SNMP. Both are fairly…
![[image] Configuring SSH on a Cisco Device](https://www.auvik.com/wp-content/uploads/2014/03/configure-configuring-SSH-Cisco-device-1800x1200-800x400.jpg)
Configuring SSH on a Cisco Device
SSH (Secure Shell) is a command line interactive interface, similar to Telnet, but encrypted. Learn how to configure it in 6 simple steps…
The Pros and Cons of VPN Split Tunneling
Should you use VPN split tunneling? Here's what you need to know to decide.
Configuring and Troubleshooting Multicast Protocols
There are two important protocols required to get your network to forward multicast packets. Here's how to configure & troubleshoot them.
What Is Multicast Networking and How Does It Work?
Multicast networking is based on the concept that a single packet can be sent by a server & it will be received by many receivers. Here's…
Special IP Address Ranges and When to Use Them
There are several special IP address ranges that have specific purposes. Network engineer Kevin Dooley explains what they are & the…
![[image] An Introduction to Subnetting](https://www.auvik.com/wp-content/uploads/2020/09/subnetting-primer-1800x1200-1-800x400.png)
An Introduction to Subnetting
You don't need that subnet calculator! Not when you have this handy guide to subnetting using both mask and CIDR notation.
Implementing a Bring Your Own Device Policy In Your Organization
A bring your own device policy is more important than ever since users can bring unsecured personal devices into your office. Here's how…
Why a Zero-Trust Network Is More Desirable—and Achievable—Than Ever
The cybersecurity landscape has changed a lot thanks to the increase in cloud-based services, and zero-trust is now an extremely…
How to Configure Syslog on a Cisco Device
Essentially every modern network device has at least some syslog capabilities. Here's how to configure syslog on Cisco devices.
What Is Syslog and How Does It Work?
Almost every device on a network has a syslog agent you can use to send messages to a central location. Here's how the network-based…
An Introduction to Web Proxies
Web proxies intercept traffic from your systems as they move to others, analyze the packets, and send the data along.
Not All Hacks Are the Same, Plan Your Network Defenses Accordingly
There’s a vast difference between the incredibly sophisticated long-term attacks against high-profile companies and government…
![[image] 3 Switch Features You Should Never Change](https://www.auvik.com/wp-content/uploads/2018/01/network-switch-features-caution-errors-1800x1200-800x400.jpg)
3 Switch Features You Should Never Change
In a handful of recent incidents, I helped clients troubleshoot network problems. The errors turned out to be switch features that were…
![[image] The Why and How of Syncing Clocks on Network Devices](https://www.auvik.com/wp-content/uploads/2017/11/syncing-clocks-NTP-network-time-protocol-1800x1200-800x400.jpg)
The Why and How of Syncing Clocks on Network Devices
One of the keys to effective network management is syncing clocks on all network devices. There are really two ways to do it.
![[image] Simple Network Redundancy: Creating Maximum Availability With Minimum Complexity](https://www.auvik.com/wp-content/uploads/2017/08/simple-network-redundancy-1800x1200-800x400.jpg)
Simple Network Redundancy: Creating Maximum Availability With Minimum Complexity
Complexity is an enemy to reliability. The more complex something is, the harder it is to understand, the greater the chance of human…
![[image] The Benefits of Great Network Configuration Management](https://www.auvik.com/wp-content/uploads/2017/06/network-configuration-management-1800x1200-800x400.jpg)
The Benefits of Great Network Configuration Management
Configuration management is one of those network management topics people often neglect. It’s not very exciting—but it’s incredibly…
The New DR: What To Do When the Internet Is Down
With the move to cloud, disaster recovery has become a special challenge. You now have to worry about what you’ll do if the Internet…
![[image] How to Adjust TCP Window Size to Improve Network Performance](https://www.auvik.com/wp-content/uploads/2017/04/tcp-window-rant-1800x1200-800x400.jpg)
How to Adjust TCP Window Size to Improve Network Performance
Are you seeing poor network performance but with link utilization well below 100%? You might have an issue with your TCP window size.…
Network Basics: An Introduction to SD-WANs
The basic idea of an SD-WAN is to reduce MPLS or other fixed internal WAN circuit costs by shunting some or all of your traffic over…
What to Look for in a Next-Generation Firewall
Considering a next-generation firewall? To help you understand the huge array of available options, engineer Kevin Dooley describes the…
Network Basics: What Is Link Aggregation & How Does It Work?
Link aggregation is a way of bundling a bunch of individual Ethernet links together so they act like a single logical link.
![[image] Implementing ACLs on a Cisco ASA Firewall](https://www.auvik.com/wp-content/uploads/2016/11/acl-cisco-asa-firewalls-1800x1200-800x400.jpg)
Implementing ACLs on a Cisco ASA Firewall
The first line of defense in a network is the access control list (ACL) on the edge firewall. The challenge is that while ACLs can be…
![[image] 6 Common Spanning Tree Mistakes and How to Avoid Them](https://www.auvik.com/wp-content/uploads/2016/10/spanning-tree-mistakes-1800x1200-800x400.jpg)
6 Common Spanning Tree Mistakes and How to Avoid Them
Spanning tree is a Good Thing. It saves you from loops, which will completely shut down your client's network. But it has to be…
Network Documentation Best Practices: What to Create & Why
Everybody agrees network documentation is extremely important, but there tends not to be a lot of agreement on what that documentation…
![[image] Defending Network Infrastructure Against Attack – Part 2](https://www.auvik.com/wp-content/uploads/2016/05/network-infrastructure-security-armored-knights-1800x1200-800x400.jpg)
Defending Network Infrastructure Against Attack – Part 2
Since perfect network security is impossible, your goal is to cover as many of the risk areas as you can with the budget you have. In…
![[image] Defending Network Infrastructure Against Attack – Part 1](https://www.auvik.com/wp-content/uploads/2016/05/network-infrastructure-security-armored-knights-1800x1200-800x400.jpg)
Defending Network Infrastructure Against Attack – Part 1
It’s impossible to create perfect network defenses. But it's not terribly hard or expensive to mount an effective defense. Let’s…
![[image] The 4 Steps to Safely Removing a Network Device](https://www.auvik.com/wp-content/uploads/2016/03/remove-device-shutdown-network-off-1800x1200-800x400.jpg)
The 4 Steps to Safely Removing a Network Device
Unused gear sitting on a network can get very expensive. Get it off there! Here are some general best practices for removing network…
![[image] Managing User Access & Authentication in a Cloud-Hosted Environment](https://www.auvik.com/wp-content/uploads/2016/02/cloud-migration-user-authentication-halt-sign-1800x1200-800x400.jpg)
Managing User Access & Authentication in a Cloud-Hosted Environment
One of the things that becomes more important in a cloud-based application environment is managing user access and authentication. Part 3…
![[image] Configuring an Internet Connection for a Cloud-Hosted Environment](https://www.auvik.com/wp-content/uploads/2016/02/cloud-migration-internet-connection-pipes-1800x1200-800x400.jpg)
Configuring an Internet Connection for a Cloud-Hosted Environment
When a company’s application infrastructure moves to the cloud, a reliable Internet connection becomes mandatory. Unfortunately, the…
![[image] Here’s What a Network Needs After a Cloud Migration](https://www.auvik.com/wp-content/uploads/2016/01/cloud-migration-network-management-goose-1800x1200-800x400.jpg)
Here’s What a Network Needs After a Cloud Migration
In this three-part series, we dig into the implications of a cloud migration and outline some of the network changes that are required to…
![[image] Migrating a Cisco ASA Firewall Configuration From Old Syntax to New](https://www.auvik.com/wp-content/uploads/2015/12/migrating-cisco-asa-firewall-configuration-1800x1200-800x400.jpg)
Migrating a Cisco ASA Firewall Configuration From Old Syntax to New
Cisco made huge changes to the configuration syntax on ASA firewalls starting in version 8.3. Here are some real-world pointers for…
![[image] Google, Zero-Trust Networks, and the Future of Security](https://www.auvik.com/wp-content/uploads/2015/05/zero-trust-network-security-1800x1200-800x400.jpg)
Google, Zero-Trust Networks, and the Future of Security
Back in January, I blogged about zero-trust network architecture as an emerging trend. Zero-trust is now in the news again with Google's…
![[image] How to Configure IPv6 on Cisco Devices](https://www.auvik.com/wp-content/uploads/2015/05/configure-IPv6-network-cables-1800x1200-800x400.jpg)
How to Configure IPv6 on Cisco Devices
In this followup to What Every Network Admin Should Know About IPv6, network engineer Kevin Dooley shows you how to enable and configure…
![[image] What Every Network Admin Should Know About IPv6](https://www.auvik.com/wp-content/uploads/2015/05/ipv6-network-design-admin-2015-1800x1200-800x400.png)
What Every Network Admin Should Know About IPv6
IPv6 comes pre-enabled on a lot of network devices — that’s dangerous unless you’re in control. Here’s what you need to know to…
![[image] An Introduction to Authentication Protocols](https://www.auvik.com/wp-content/uploads/2015/03/authentication-protocols-locks-1800x1200-800x400.jpg)
An Introduction to Authentication Protocols
Centralized authentication improves the manageability & security of your network. In this article, network engineer Kevin Dooley…
![[image] The Secrets to Drawing Effective Network Diagrams](https://www.auvik.com/wp-content/uploads/2017/10/auvik-network-maps-use-case-2017-1800x1200-800x400.png)
The Secrets to Drawing Effective Network Diagrams
Good network diagrams aren't hard to make, yet they're distressingly rare. Even network engineers with years of experience often make…
![[image] 8 Networking Trends to Watch in 2015](https://www.auvik.com/wp-content/uploads/2015/01/networking-trends-2015-auvik-1800x1200-800x400.jpg)
8 Networking Trends to Watch in 2015
What networking trends will we see come to life in 2015? Think security, speed, and cloud.
![[image] How to Explain Highly Technical Ideas to Non-Technical People](https://www.auvik.com/wp-content/uploads/2014/12/technical-ideas-explain-communicate-1800x1200-800x400.jpg)
How to Explain Highly Technical Ideas to Non-Technical People
Executives really appreciate techies who communicate well. It's a rare skill and it translates into promotions and bigger paychecks…
![[image] Stop! Are You About to Make One of These Network Management Mistakes?](https://www.auvik.com/wp-content/uploads/2014/08/network-management-mistakes-danger-sign-1800x1200-800x400.jpg)
Stop! Are You About to Make One of These Network Management Mistakes?
Network pro Kevin Dooley shares the stories of four painful network management mistakes -- and tips on how you can avoid the same goofs.
![[image] How to Troubleshoot Routing Problems](https://www.auvik.com/wp-content/uploads/2014/07/troubleshoot-network-routing-problems-traffic-1800x1200-800x400.jpg)
How to Troubleshoot Routing Problems
Routing problems tend to emerge when you're first setting up a new piece of network equipment, and when something has failed. Usually…
![[image] Verifying Physical Connectivity](https://www.auvik.com/wp-content/uploads/2014/05/network-management-verifying-physical-connectivity-1800x1200-800x400.jpg)
Verifying Physical Connectivity
Many physical troubleshooting exercises come down to the process of swapping out elements until the problem goes away. The key is to…
Out-of-Band Management
Out-of-band management provides a way to log into your network devices without going through the same network through which the data…
![[image] Configuring Syslog and SNMP on a Cisco Device](https://www.auvik.com/wp-content/uploads/2014/04/configuring-syslog-SNMP-Cisco-device-1800x1200-800x400.jpg)
Configuring Syslog and SNMP on a Cisco Device
There are two common ways to get management information about your network devices to a central server: syslog and SNMP. Both are fairly…
![[image] Configuring SSH on a Cisco Device](https://www.auvik.com/wp-content/uploads/2014/03/configure-configuring-SSH-Cisco-device-1800x1200-800x400.jpg)
Configuring SSH on a Cisco Device
SSH (Secure Shell) is a command line interactive interface, similar to Telnet, but encrypted. Learn how to configure it in 6 simple steps…