the concept behind this to be working is pretty simple , we must understand the role of one of the ASA as DHCP relay agent .
From the ASA acting as a DHCP relay agent you should be able to ping the DHCP server from your inside interface , or the interface behind which the DHCP clients are so for example
ping inside 192.168.1.12 , 192.168.1.12 being DHCP server ip address . You just need to ensure that you have inside ip address and destination DHCP server ip address defined in the crypto access-list .
Once we have done that we are clear on crypto side of things and we then need to configure ASA as a DHCP client and the configuration is simple
dhcprelay server 192.168.1.12 outside dhcprelay enable inside
By doing that we are setting up ASA to act as a relay agent during DORA process (by the use of command :- dhcprelay enable inside) and also defining our DHCP server on outside (dhcprelay server 192.168.1.12 outside)
To understand more on how DHCP server relay operation refer to the document
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...