To determine what KMS server a machine would use by default, use nslookup (substituting the actual customer domain):
C:\> nslookup -q=srv _vlmcs._tcp.domain.com
Server: dc001.domain.com
Address: 10.170.89.2
_vlmcs._tcp.domain.com SRV service location:
priority = 0
weight = 0
port = 1688
svr hostname = kms-srv2.domain.com
_vlmcs._tcp.domain.com SRV service location:
priority = 0
weight = 0
port = 1688
svr hostname = win8-kms-srv.domain.com
kms-srv2.domain.com internet address = 10.170.89.213
win8-kms-srv.domain.com internet address = 10.170.89.214
To see what KMS server has been cached on the current MM, you will need to look in the Registry. I believe that the user account mentioned here will always be the same, but in the worst case, search for keys named "DiscoveredKeyManagementServiceName".
HKEY_USERS\S-1-5-20\Software\Microsoft\Windows NT\CurrentVersion\SoftwareProtectionPlatform\55c92734-d682-4d71-983e-d6ec3f16059f\ae2ee509-1b34-41c0-acb7-6d4650168915
DiscoveredKeyManagementServiceName (REG_SZ)