Outbound Neighbors Samba DRS Replication:WERR_BAD_NETPATH

samba-ad-dc
samb4
samba-replication

#1

Hi,

to one single Slave DC seems to be disturbed. I’ve observed this on all other DCs:

==== OUTBOUND NEIGHBORS ====

DC=ForestDnsZones,DC=top2,DC=top1
        Default-First-Site-Name\DC-SLAVE via RPC
                DSA object GUID: ID
                Last attempt @ Wed Jun  5 14:42:40 2019 CEST failed, result 53 (WERR_BAD_NETPATH)
                2 consecutive failure(s).
                Last success @ NTTIME(0)

DC=DomainDnsZones,DC=top2,DC=top1
        Default-First-Site-Name\DC-SLAVE via RPC
                DSA object GUID: ID
                Last attempt @ Wed Jun  5 14:42:40 2019 CEST failed, result 53 (WERR_BAD_NETPATH)
                2 consecutive failure(s).
                Last success @ NTTIME(0)

DC=top2,DC=top1
        Default-First-Site-Name\DC-SLAVE via RPC
                DSA object GUID: ID
                Last attempt @ Wed Jun  5 14:42:40 2019 CEST failed, result 53 (WERR_BAD_NETPATH)
                2 consecutive failure(s).
                Last success @ NTTIME(0)

CN=Schema,CN=Configuration,DC=top2,DC=top1
        Default-First-Site-Name\DC-SLAVE via RPC
                DSA object GUID: ID
                Last attempt @ Wed Jun  5 14:42:40 2019 CEST failed, result 53 (WERR_BAD_NETPATH)
                2 consecutive failure(s).
                Last success @ NTTIME(0)

CN=Configuration,DC=top2,DC=top1
        Default-First-Site-Name\DC-SLAVE via RPC
                DSA object GUID: ID
                Last attempt @ Wed Jun  5 14:42:40 2019 CEST failed, result 53 (WERR_BAD_NETPATH)
                2 consecutive failure(s).
                Last success @ NTTIME(0)

Has someone observed something like this already?

Cheers,
SrTux

EDIT: There is something related in the log:

DC Master

[2019/06/05 14:41:55.387245,  0, pid=2056] ../../source4/librpc/rpc/dcerpc_sock.c:245(continue_ip_open_socket)
  Failed to connect host $ip (ID._msdcs.top2.top1) on port 135 - NT_STATUS_CONNECTION_REFUSED.

DC Slave

[2019/06/05 15:02:54.961570,  0, pid=22535] ../../source4/rpc_server/common/forward.c:55(dcesrv_irpc_forward_callback)
  IRPC callback failed for DsReplicaSync - NT_STATUS_OBJECT_NAME_NOT_FOUND

#2

If I remember correctly we observed WERR_BAD_NETPATH with a Slave with 2 NICs. If you have the same problem, you can use the following commands, to tell Samba to use only one of the NICs (in this case eth0):

ucr set samba/interfaces/bindonly=yes
ucr set samba/interfaces="lo eth0"
systemctl restart samba-ad-dc.service

#3

@Andreas_T Thank you but there is only a single NIC.

I’ve found a solution here. Rebooting the affected DC and not only restarting samba fixed this issue at least for now.

EDIT: Maybe it was caused by the samba update last week?