It will keep going between the two. If you want it to use a primary unless it is unavailable, you would pick failover.
As for if both are unavailable, there is a configuration option on the listener that allows you to accept if ldap is unavailable. You will see your work queues grow until the ldap returns.
The ldap is cached if they are already in the list it knows about. You can setup information on how many entries to cache and for how long. Under ldapconfig->edit->pick the ldap server configuration->server->cache.
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...