Yes, that is correct. In routers and switches there is a slow path (process switching), and a fast path (CEF or MLS). The fast path is taken when packets entering the router need to be switched out another interface. These packets are interrupt-switched (with CEF on routers), or hardware-switched (MLS on switches).
When you send a ping to an IP address belonging to the router, it must be process switched (slow path), and it needs to wait for the process scheduler to allocate CPU resources to send a reply. If the CPU is busy doing other things, this reply can be delayed, or even lost.
Best practice for testing WAN links (or any links) is to pass the traffic between workstations, so that the traffic takes the fast-path.
This document gives several answers on frequently asked questions for PFRv3 channel state behavior.
Q1: What are all the channel operational states from a BR (border role) perspective and what are the rules/conditions to be in each st...
The need was to reach an host inside a LAN through a VPN connection managed by the LAN gateway (Cisco 1921).
The LAN gateway performs NAT and there was a dedicate nat rule for the host i wanted to reach through VPN.
I couldn't connect to the hos...
We have 3 identical switches configured by someone else and would like to claim some of the Gigabit ports(G1/G2/G3/G4) for use on servers. When we try to change the wiring and configuration, we run in to connectivity issues. Attached is a des...