Voice VLANs: why bother separating
Not tidiness. It makes QoS, security and troubleshooting each substantially easier.
Writing
Design
Dial plans that do not fight you
Most dial plan trouble is inconsistency about when digits are added or removed.
QoS: the parts people skip
Marking traffic achieves nothing on its own. The queue is where the work happens.
Designing a hub and spoke that tolerates outages
Every remote site will lose its link. Design for what happens during, not just after.
Latency you cannot engineer away
Geostationary orbit imposes a floor. Design for it rather than trying to tune past it.
Default routes and the black holes they create
A default route means "send it here and hope". Sometimes hope is misplaced.
VRFs: separation without separate hardware
One router, several routing tables that cannot see each other. Where that helps and what it costs.
Static routes: when they are the right answer
Dynamic routing is not automatically better. Sometimes the static route is the professional choice.
Route redistribution and the loops it creates
Two protocols feeding each other at two points will create a loop. Here is how to stop it.
BGP for people who run a single uplink
You may not need BGP. If you do, the parts that matter are few.