The question of the bandwidth of a VPN tunnel may be interesting but is quite difficult. Since the VPN is a virtual interface it does not have any inherent bandwidth. If you are running VPN in conjunction with GRE you might look at the bandwidth of the GRE tunnel. But that defaults to 9K, and that value is obviously not accurate for most implementations.
Since the VPN tunnel is a virtual implementation I would say that realistically its bandwidth is the bandwidth of the slowest/smallest link between the source peer and the destination peer. And there is not any command that will display that bandwidth.
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...