i have a 1841 at Head office configured as ezvpn server. Branch offices are vpn client remote 4.8. everything is fine just that the data after encryption doubles in size. for example the total data which is to be sent to the branch is 512 kb, the wan link utilization is arround 900 kb.
can some one help why is this so; 1 thing that just came to my mind.....PADDING...could this be the reason.....how can it be overcome.
Another possibility, when not doing end-to-end IPSec, is full packets that are encrypted often need to be spit into two packets to allow room for the IPSec header. Similar to a interface which receives packets with a MTU larger than it supports. If this is happening, insure the end sources use a smaller MTU that allows the IPSec header to be added so the original packet doesn't need to be fragmented.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...