External Users Authentication & on box authentication

Hi, not my area of expertise, but it looks pretty binary (either local or remote). I created a local user and authenticated the LTM UI just fine. Then flipped authentication to remote and was unable to authenticate any longer. This TACACS+ server hasn't been working properly for some time. Two thoughts: The TACACS authentication screen lets you add multiple TACACS servers for resiliency. If there is any authentication issue blocking user access, the admin and root accounts remain local for you to access and perform any necessary config tweeks.