When the satellite link is not the problem
The most expensive, least understood component gets blamed for everything. Prove it before escalating.
Platform
Linux
Debian, Ubuntu, RHEL and their relatives. The commands are standard unless the article says otherwise.
TCP over long fat pipes
High bandwidth and high latency together defeat default TCP settings.
Vendor defaults that will hurt you
Shipping defaults are chosen so the device works out of the box, not so it is safe.
Convergence: measuring what your network actually does
Everyone claims sub-second failover. Very few have measured it.
Cable faults that look like software faults
Hours get spent in configuration for problems that live in the first metre of the path.
Jumbo frames: worth it, or not
They help in specific places and cause silent breakage everywhere else. Decide deliberately.
When traceroute lies
Asterisks are not failures and high latency at hop four is usually nothing. Read it correctly.
TTL as a diagnostic instrument
The time-to-live field quietly tells you how many hops a packet took. That is more useful than it sounds.
Reading a packet capture without drowning
A capture with two million frames is not evidence until you have reduced it. Here is the order that works.
ARP, and the day two devices claimed one address
Intermittent, symmetrical, affects everyone on the subnet. Duplicate addresses have a signature.