[Samba] Windows 10 Office 2016 slow accessing samba network shares

[Daulton Theodore]

I have a to a samba server (4.4.16) on built on Solaris 11 samba pkg. It is a member of an Active directory domain. Users, for some time, have been experiencing long (20 -40 second) delays when browsing to, opening and writing a network share on the server.  Attempts to do any of those results in a dialogue box being displayed showing:

Contacting server: \\<server-name> \share

Workstations: Windows 10
Application: MS Office 2016

I would appreciate if anyone has suggestions to getting past this hurdle. Here is a sanitized copy of smb.conf.

# Global parameters
[globals]
   netbios name  = NBNAME
   server string = %L
   workgroup     = DOMAIN_NAME
   browsable     = no
   local master  = no

   allow hosts   = 127.0.0.1 aaa.bbb.10. aaa.bbb.dd. aaa.bbb.cc.1kk/255.255.255.192 aaa.bbb.cc.ll/255.255.255.224 aaa.bbb.cc.69 aaa.bbb.18.1/255.255.255.224 aaa.bbb.18.30 10.0.2.15 aaa.bbb
.116.0/23

   hosts deny = 0.0.0.0/0

   security      = ADS
   realm         = xx.yy.ca


   machine password timeout = 314496000
   name resolve order = wins lmhosts host bcast

   remote announce = aaa.bbb.nnn.mmm

#   wins support = yes
   wins server = aaa.bbb.x.y aaa.bbb.x.z
   winbind use default domain = true

#  force Samba to bind only to public network
   interfaces    = aaa.bbb.ff.gg/255.255.255.0
   bind interfaces only = yes
   socket options = SO_KEEPALIVE IPTOS_LOWDELAY TCP_NODELAY
   deadtime     = 0

#  added 20150422
   server signing = auto
   client signing = auto

#  from MIKEY's Readme
   client lanman auth = no
   client ntlmv2 auth = yes
   client plaintext auth = no
   client use spnego = yes
   client schannel = yes
   lanman auth = no
   ntlm auth = no

#  20171101
   server min protocol = SMB2_10
   client min protocol = SMB2
   client max protocol = SMB3


#  Encrypt all passwords stored in /etc/sfw/samba/private/smbpasswd
   encrypt passwords = yes
   username map = /etc/samba/lib/nt-names


#  not allowed to log in
   invalid users = root daemon bin sys adm lp listen sshd\
                   erl webspirs samba rob jan daulton

   writeable     = yes

#  A wormable code-execution bug has lurked in Samba for 7 years -  20170528
#  https://arstechnica.com/security/2017/05/a-wormable-code-execution-bug-has-lurked-in-samba-for-7-years-patch-now/
   nt pipe support = no

#  Debug Logging information
   log level = 5
   log file = /etc/samba/var/log.%m:%U:%I
   max log size = 2000
   debug timestamp = yes

~~~~~~~~~~~~~~~~~~~~~~~~
Daulton Theodore
Carleton University
Library, Systems Department
Vmail: (613) 520-2600, ext. 8352