batchpatch connection issues after aws move

[ddobek]

We have a number of windows servers onsite in a datacenter, that are being migrated (lift and shift) to AWS. its more a replication to a new aws ec2 instance, and the old vm is powered off after migration. The new aws vm’s maintain the name, get a new IP address – but when trying to connect to any of the servers that have been moved to aws, BP fails to get any info from them. I’ve verified all the security groups, firewalls, etc are open, allowed and can see the tcp connections being established and not being dropped. Whether i check updates, get OS info, disk space available – any query fails. I get error message of “failed to retrieve data”, or RPC is unavailable, or Error 1601 failed to retrieve wmi info, etc. FW’s do not seem to be the problem, as i mentioned i can see tcp connections established. Any ideas on what i can look at or test, to see why an AWS server isn’t able to be connected or talk to BP ? Thanks.

[doug]

Well let’s start with the actual error message that you receive. The exact/specific error message itself is important to diagnose the cause of the problem. Start here:

BatchPatch Windows update: Error 1601

[ddobek]

Thanks Doug, yes i’ve seen and read that article prior to submitting the request. So it says that error is usually due to 2 reasons:1) access denied – not the issue: same user account as pre-aws migration. to confirm i’ve added my individual account to the server, the same account i use to login to the server hosting batchpatch. 2) the server is offline -nope, the server is online. Firewall? nope firewall is not in the way. TCP connections get established.

I also validated wmi is not corrupted. Server is still on the same domain as before, same user, not permission denied errors, just basic failures without much info as to why. RPC is running on the server, server has been reboot multiple times.

Various BP queries result in:
Windows Update Messages
Error 1601: Failed to retrieve WMI info. The RPC server is unavailable. (Exception from HRESULT: 0x800706BA) – 15:34:00
Get Host Name
The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)
Disk Space (%)
Failed to retrieve data for C:
All Messages
04/30 15:35:21> Get host name: The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)
04/30 15:34:38> Get host name: Attempting to retrieve host name…
04/30 15:34:00> Windows Update: Error 1601: Failed to retrieve WMI info. The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)
04/30 15:33:18> Windows Update: Initializing…
04/30 15:33:18> Windows Update: Queued… (Check for available updates)
04/30 15:32:37> Get disk space: Failed to retrieve data for C:

[doug]

RPC server is unavailable means that the BatchPatch computer is not getting any response from the target computer. We have only ever seen this be caused by the computer being offline (or the RPC service being stopped), a network issue preventing communication, a firewall, or some type of anti-virus or similar security software that is blocking/dropping communications, which effectively speaking would be considered a firewall even if it’s not being billed as such.

FYI a WMI failure/error or an Access Denied issue would have different error text, so we can rule those out as the cause of the error that you are seeing. The reasons mentioned above are really the only reasons we have ever seen for RPC server is unavailable.

You mentioned that the issue isn’t a firewall, but firewall is by far the most common reason for this error to occur, so I will still be focusing on that as the probable cause. It doesn’t JUST include the Windows firewall. It can include any type of software or hardware firewall or network device in between the machines. In this case I’m not sure if your setup included moving the BatchPatch machine as well as the target machines into AWS. Regardless, I would suggest you look at the AWS built-in firewall/network rules too.

Additionally, review the notes on this page about DCE/RPC

Also review this page and consider enable Windows firewall logging temporarily to see if there is anything visible in the logs that helps you troubleshoot further.

[Author]

Posts