[Samba] RPC Server Unavailable - Error

[Anantha Raghava]

Hi,

The problem still persists. Just now, we got the "RDC Server 
unavailable" error in one of the server. When this error is reported bu 
RSAT, there is no specific log in the logon server. Also, samba-tool 
dbcheck reports '0' errors. We stopped samba service on the logon 
server, close RSAT and reopen, there is no error. Or when we simply 
restart the samba service, the error disappears.

Downgrading may may not be an option for us at the moment.

Is it related to CVE-2019-12435, that is fixed in 4.10.5? If we upgrade 
to 4.10.5, will this error get fixed?

Thanks in advance for your support.

Thanks & regards,

Anantha Raghava

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On 20/06/19 3:19 pm, Anantha Raghava wrote:
>
> Hi,
>
> This morning, again we encountered the same issue. When RSAT reported 
> the RPC Server error, the replication between servers was failing as well.
>
> As you suggested, we rung the dbcheck command, which threw the 
> mismatch on count of deleted objects. 3 servers had 3 entries in 
> deleted objects whereas the 4th server had 4 entries in deleted 
> objects. samba-tool dbcheck --reindex did not fix this part. We ran 
> samba-tool dbcheck fix --cross-ncs --fix command on all severs and 
> this fixed the mismatch in number of objects. Again we ran samba-tool 
> dbchek --reindex on all 4 servers.
>
> The problem seems to have got fixed. We have kept the servers under 
> observation. For the moment, we have raised the log level to 5. In 
> case the issue surfaces once again, I will notify here with logs as well.
>
> Thanks for your guidance.
>
> Thanks & regards,
>
> Anantha Raghava
>
> Do not print this e-mail unless required. Save Paper & trees.
>
> On 18/06/19 4:54 pm, L.P.H. van Belle via samba wrote:
>>   
>>
>>> -----Oorspronkelijk bericht-----
>>> Van: samba [mailto:samba-bounces at lists.samba.org] Namens
>>> Rowland penny via samba
>>> Verzonden: dinsdag 18 juni 2019 13:15
>>> Aan:samba at lists.samba.org
>>> Onderwerp: Re: [Samba] RPC Server Unavailable - Error
>>>
>>> On 18/06/2019 12:02, Anantha Raghava via samba wrote:
>>>> Hi,
>>>>
>>>> We did not upgrade in the real sense of upgrade. We did not
>>> directly
>>>> apply the patch on the servers. Our steps were as follows:
>>>>
>>> You can reduce that down to 'we upgraded directly to 4.10.x
>>> from 4.7.x'
>>>
>>> Can I also suggest that you stop upgrading that way, if you
>>> do it often
>>> enough, you will eventually exhaust the ridpool
>>>
>>>> We have to run samba-tool dbcheck and check the output. I
>>> will update
>>>> it back here.
>>>>
>>>> Do I have to run this command on all 4 servers? or one server which
>>>> looks like giving trouble?
>>> You should only need to run it once on the PDC Emulator role owner,
>>> replication should do the rest.
>>>
>>> If this doesn't work, then I would suggest you start downgrading again.
>> If it looks if downgrading is needed, then first try to run : samba-tool dbcheck --reindex
>> That might help fixing it. ( run it on every DC ) !
>>
>> And beware the the RPC ports have changed, so do check.
>> https://wiki.samba.org/index.php/Samba_AD_DC_Port_Usage    Dynamic RPC Ports
>>
>>
>> Greetz,
>>
>> Louis
>>
>>
>>