If you define IgnoreAcctSignature, it
                  prevents the server from checking the Authenticator field in requests
                  received from this client. Contrary to its name, it applies to all message
                  types and also prevents checking the
                  Message-Authenticator attribute. This parameter is
                  useful because some clients do not send Authenticators that conform to
                  RADIUS RFCs. 
               By default, the server logs and ignores messages that
                  do not have a correct Authenticator, or any messages that do not have a
                  correct Message-Authenticator attribute. Regardless
                  of the setting of this parameter, the server always sends a correctly
                  computed Authenticator and Message-Authenticator
                  attribute. 
               
                  CAUTION
                  This parameter is seldom required with
                     current RADIUS implementations. You should first check that the shared
                     secret between Radiator and client is correct before enabling this
                     parameter.
                
               If you get bad authenticator log messages and the
                  accounting requests are not being stored even though authentication as
                  such does not fail, and you have checked that the shared secrets are
                  correct, try enabling IgnoreAccSignature. The bad
                  authenticator log message looks this:
               Bad authenticator in request from <client name> (<nas identifier>)
               If
                  you get bad EAP Message-Authenticator log messages and you have checked
                  that the shared secrets are correct, it is possible that the NAS is
                  sending an incorrect implementation of Message-Authenticator. Try enabling
                  IgnoreAccSignature. The bad EAP Message-Authenticator
                  log message looks this:
               Bad EAP Message-Authenticator
               
                  Tip
                  Some NASs have separate secrets for authentication and
                     accounting requests.
                
               # brian.open.com.au has a broken legacy NAS
<Client 10.20.30.40>
      Identifier brian.open.com.au
      Secret 666obaFGkmRNs666
      IgnoreAcctSignature
</Client>