This turned out to be that stopping the IAS service (as I was doing to test) is not enough to cause a failover- the server must actually be non-pingable or truly down. When I shut it down completely it failed over. This means that if the IAS service stops or is stopped inadvertently- no fail over and no access. To protect against this we setup our monitoring software to check the two IAS servers IAS service is running I don’t know that it played a role but the settings I used were: Default Retries (1-10)    4  Default Timeout for Reply (1-30)  (Sec)   1  Default Dead Time (0-2000)  (Min)   10 (to allow reboots for updates etc)  Default Key String (0-128 Characters)      Source IPv4 Address      Source IPv6 Address   (X:X:X:X::X)  
  PC 5548  Failover Radius IAS not working with 802.1x Hi- I’m looking for some help or leads to help me with this. Clients can authorize with either server IAS1 or IAS2, but if client authorizes on IAS1 and then re-authentictes  (ie re-docks) while IAS1 is down, IAS2 has no connection attempt recorded and the client’s security log states A request was made to authenticate to a wired network. Subject: Security ID:                         host/1x.mydomain.com                 Account Name:                 -                 Account Domain:                             -                 Logon ID:                             0x0 Interface:                 Name:                                  Intel(R) 82579LM Gigabit Network Connection Additional Information                 Reason Code:                    Explicit Eap failure received (0x50005)                 Error Code:                         0x40420110   Logs from switch record (with my comments) –start at bottom   2147482623     07~May~2012 16:07:17    Warning      %STP-W-PORTSTATUS: gi1/0/24: STP status Forwarding          2  2147482624     07~May~2012 16:06:47    Info         %LINK-I-Up:  gi1/0/24         I then plug cable back in but there is no corresponding log entry on the IAS2 server so I don’t believe it is contacted 3  2147482625     07~May~2012 16:06:47    Warning      %SEC-W-PORTUNAUTHORIZED: Port gi1/0/24 is unAuthorized         4  2147482626     07~May~2012 16:06:21    Warning      %LINK-W-Down:  gi1/0/24         I then unplug cable and disable IAS service on IAS1    5  2147482627     07~May~2012 16:04:06    Warning      %STP-W-PORTSTATUS: gi1/0/24: STP status Forwarding          6  2147482628     07~May~2012 16:03:41    Info         %SEC-I-PORTAUTHORIZED: Port gi1/0/24 is Authorized          7  2147482629     07~May~2012 16:03:36    Info         %LINK-I-Up:  gi1/0/24      Section above records successful auth with IAS1   The Dell 5548 switch (firmware 4.0.1.12 ) has both IAS servers specified and I’ve tried varying priority settings on the configuration of each- both at zero or one at zero and the other at 100 as I’m not clear what that should be set to for fault tolerance The basic setup  is Domain with Win2003 IAS servers with self signed certs pushed out via GPO so that it ends up in the trusted root certificate authorities computer cert store. I’ve tried with IAS1’s cert on both the IAS servers or unique certs for each server for the MS-CHAP V2  PEAP and allow policy set for domain computers Clients WIN7 Pro 64 configured to use computer authentication and verify certs IAS failover works fine between these servers for other purposes such as VPN access And remember PC’s will auth to both IAS servers- just not switch between them when one is down Any ideas???   Thanks for reading
PC 5548 Failover Radius IAS not working with 802.1x