test sun/security/krb5/auto/MaxRetries.java failed only on solaris 10 sparc sun4v since 7u4b10, passed with 7u4b09 and 7u3b05

log:
>>> KDCCommunication: kdc=kdc.rabbit.hole UDP:15955, timeout=4000,Attempt =1, #bytes=226
Config name: alternative-krb5.conf
>>> KdcAccessibility: reset
----------System.err:(43/2756)----------
javax.security.auth.login.LoginException: Receive timed out
at com.sun.security.auth.module.Krb5LoginModule.attemptAuthentication(Krb5LoginModule.java:763)
at com.sun.security.auth.module.Krb5LoginModule.login(Krb5LoginModule.java:580)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at javax.security.auth.login.LoginContext.invoke(LoginContext.java:784)
at javax.security.auth.login.LoginContext.access$000(LoginContext.java:203)
at javax.security.auth.login.LoginContext$4.run(LoginContext.java:698)
at javax.security.auth.login.LoginContext$4.run(LoginContext.java:696)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.login.LoginContext.invokePriv(LoginContext.java:695)
at javax.security.auth.login.LoginContext.login(LoginContext.java:594)
at Context.fromJAAS(Context.java:105)
at MaxRetries.test1(MaxRetries.java:93)
at MaxRetries.main(MaxRetries.java:63)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at com.sun.javatest.regtest.MainWrapper$MainThread.run(MainWrapper.java:96)
at java.lang.Thread.run(Thread.java:722)
Caused by: java.net.SocketTimeoutException: Receive timed out
at java.net.PlainDatagramSocketImpl.receive0(Native Method)
at java.net.AbstractPlainDatagramSocketImpl.receive(AbstractPlainDatagramSocketImpl.java:145)
at java.net.DatagramSocket.receive(DatagramSocket.java:786)
at sun.security.krb5.internal.UDPClient.receive(NetClient.java:207)
at sun.security.krb5.KdcComm$KdcCommunication.run(KdcComm.java:386)
at sun.security.krb5.KdcComm$KdcCommunication.run(KdcComm.java:339)
at java.security.AccessController.doPrivileged(Native Method)
at sun.security.krb5.KdcComm.send(KdcComm.java:323)
at sun.security.krb5.KdcComm.send(KdcComm.java:219)
at sun.security.krb5.KdcComm.send(KdcComm.java:191)
at sun.security.krb5.KrbAsReqBuilder.send(KrbAsReqBuilder.java:319)
at sun.security.krb5.KrbAsReqBuilder.action(KrbAsReqBuilder.java:364)
at com.sun.security.auth.module.Krb5LoginModule.attemptAuthentication(Krb5LoginModule.java:721)
... 21 more

passed on solaris 10 sparc sun4u, linux, windows
see comments for more details