I suggest the book "Network Warrior" by Gary Donahue. It's subtitle is "Everything You Need to Know That Wasn't on the CCNA Exam" and that's a pretty good description. It gives you a good set of deatils to reinforce what you might already know from either working in networking for a while or from having a CCNA. It also covers the Nexus line of data centre switches which might be of interest to you.
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...