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Event ID 529 from AP domain despite firewall rule

We are seeing about 5 or 6 Event ID 529 messages everyday, all from an Asia-Pacific IP address range.  The first 3 octets are always the same - 121.12.175.  To combat hacking attempts, we created a rule on our SonicWall TZ-180 appliance to block all traffic from -  In spite of this rule, we continually see these hacking attempts.  What I don't understand is why SonicWall is allowing the traffic to be passed on to the Windows 2003 SBS.  What is more disturbing is the fact that source port 4564 is known to be a worm with DDoS capabilities.  Any suggestions?
Logon Failure:
 	Reason:		Unknown user name or bad password
 	User Name:	administrator
 	Logon Type:	3
 	Logon Process:	NtLmSsp 
 	Authentication Package:	NTLM
 	Workstation Name:	ZZWLINE
 	Caller User Name:	-
 	Caller Domain:	-
 	Caller Logon ID:	-
 	Caller Process ID:	-
 	Transited Services:	-
 	Source Network Address:
 	Source Port:	4564

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1 Solution
event source please
DavidMCookAuthor Commented:

Source = Security
Category = Logon/Logoff
Type = Failure Aud
Event ID = 529

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DavidMCookAuthor Commented:
Is SonicWall not capable of blocking all traffic from the source IP?  That is my preference, that their packets be stopped at the firewall.
Carlos DiazTraining Program ManagerCommented:
I'm not sure about SonicWall configs, but it most cases, troubleshooting firewalls that let packets through that you don't want can be done in this order:

- check for a failover pass-through mode
- check that the rule/policy/acl that stops the undesired traffic comes before other rules/policies/acls that apply to the same range for permits(most firewalls use the top-down method to process rules/policies/acls)
- check that the source address/range is correct as well as the destination
- check that the protocol/protocol suites is/are correct
- check that the destination port(s) are correct

As for that source port, most source ports are generated randomly.  the important part is the destination port.
DavidMCookAuthor Commented:
co1000100 suggestion to check the order of the firewall rules may have hit on the reason.  Unfortunately, SonicWall seems to put all of the ALLOW rules first followed by the DENY rules, and I haven't been able to figure out how to change them.  Any other suggestions?
DavidMCookAuthor Commented:
I downloaded latest firmware from SonicWall.  Hopefullly that will resolve my problem.
DavidMCookAuthor Commented:
The firmware did not solve my problem.  However, I finally found the solution.  SonicWall does not let you change the order of the rules, by default.  I'm told that if you get Enhanced OS that you can, but I'm not quite sure what that is.  SonicWall sorts the most specific rule first, then ends with the most general.  To stop this intruder, I needed a rule that would float to the top.  Here's what I did:

* I first determined from the logs that the hacker was coming in on port 135, RPC for Exchange.
* Next, I determined the IP address (I know by heart after all this time) -, which is an Asia Pacific address.  SInce we don't get visitors from that part of the world, we can block the entire address range.
* Next, I created a rule that blocks all traffic from thru on port 135 when the traffic is destined for my mail server.

When I clicked Save, the rule floated right to the top of the list.  Problem is now solved.  Whew!
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