If your LDAPs are behind load balancer, so this devide takes care about availability and failover. ACS "sees" just one virtual IP. Load balancer, in turn, may use special "keep-alive" packets on speicified port in order to check LDAPs availability and latency.
If you see no failover on you LDAP servers which are behing LB, please, check load balancer configuration first.
P.S. ACS uses no special "keep alive" - you just confugring two LDAP servers and internal logic switches from first to second after timeout.
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...