I think we need to be careful when we talk about failover. The original post was clearly asking about two different scenarios
1) ASAs at two different sites
2) ASAs configured as a High Availability failover pair (Active/Standby).
The profile does work to provide failover in 1) but does not work to provide failover in 2).
I do not know the authoritative answer to the question about IP phones use of the profile. I believe that the answer ought to be that yes the phone would receive the profile after its first connection and would use the backup server identified in the profile is the primary server was not available. That is a basic functionality of the AnyConnect client and if the phone is using the AnyConnect client then it ought to support that failover.
If someone does have an authoritative answer then please speak up. Several of us would like to know the right answer here.
If my experience IOS (IPhone), Linux, Windows, MACOS with AnyConnect can all use the backup server entries in the AnyConnect profile. This is usually used when you have two data centers at diverse locations. Looks something like this inside the profile:
Failover for the ASA when using AnyConnect does not require the use of "backup servers" in the AnyConnect profile. AnyConnect connections will failover instantly. This would be for ASA devices located in the same location where failover has been configured between device.
For option 1 the failover is in the client.
For option 2 the failover is in the ASA.
I see no reason that you could not use both, but you would need two sets of ASA's with different host names. Either located local or diverse.
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...
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