TSHOOT – GRE DEEP DIVE!!! MTU / Fragmentation / TCP-MSS / PMTUD / Recursive Routing / Interface States / must know information for exam day!

The graphic above shows a VPN Tunnels two modes (Transport and Tunnel), along with how their payloads differ when configured with AH (Authentication only) and ESP (Encryption) on the tunnel, and what protocols correlate with all of it. The basics of GRE and IPSec Tunnel Modes and Packet Formats Basic GRE tunnel configuration has absolutely … Continue reading TSHOOT – GRE DEEP DIVE!!! MTU / Fragmentation / TCP-MSS / PMTUD / Recursive Routing / Interface States / must know information for exam day!

VPN: DEEP Dive into different VPN Packet Types, Packet Headers, and the differences between VPN Packets and their Modes!

This first image is a break down of the different types of VPN Packet Type by the headers / trailers (or lack thereof), and the following of your typical IPSec VPN Packet Type: The VPN generic representation of the IPSec VPN Packet above works for a general review, but there are details in the headers … Continue reading VPN: DEEP Dive into different VPN Packet Types, Packet Headers, and the differences between VPN Packets and their Modes!