Blog for Technologists

Overview I was recently troubleshooting a vPC port channel issue with a pair of Nexus 5500 switches that were trying to implement new port channels to two NetApp controllers. I [...]

Do you recall when service providers typically had to call upon Remote Trigger Blackhole (RTBH) to mitigate DDOS attacks? With RTBH, we only had two methods, source-based and destination-based. We [...]

Do you remember source routing, used in token ring bridging networks? If you’re relatively new to networking, you may not know about it. In source routing, the hosts determine the [...]

I was recently troubleshooting an HSRP issue with two Nexus 5500 switches that both were in the active state. (I was trying to add HSRP to a long-running pair of [...]

I was recently troubleshooting an HSRP issue with two Nexus 5500 switches that both were in the active state. The root cause appeared to be a missing LAN_Base license. Although [...]

Edited by Marilyn Outerbridge Editor’s note: This is the latest in a series of blog posts of NAT configuration. Click below for previous installments: Part 1 Part 2 Part 3 Table [...]

One of the complications of gateway certificates is replacing old certificates on CUCM, after a secure gateway dies. Take it from someone who has been there, the easiest way to [...]

Here’s help with getting Tomcat Certificates added to a Cisco Unified Communications Manager Web page.

The Citrix NetScaler Product Group had a

I’ve been working with two large organizations recently on projects which include identifying gaps in network management tools (in the broad sense, including UC management) and related processes. That inspired [...]

If you use Cisco VIRL to create virtual network models, here’s help with loading issues that occur when modeling multiple devices.

Skyport Systems’ new SkySecure product, demonstrated at Network Field Day 11, offers novel solutions to vexing server security challenges. Here’s our review.