CentOS 6: Show supported SMB protocol

Question

I have a CentOS 6 that can mount a share from a Windows Server 2008. However, it can't mount share from a newly purchased NAS or from a share on a Windows 11 machine.

How to I view the supported SMB protocol on the CentOS machine?

When mounting the share from a Windows 11 machine:

mount -t cifs -o username=TEST //172.17.154.188/New  /mnt/ntfs

I have tried specifying different version also, with vers=3.0 and vers=2.0.

And the error

mount error(112): Host is down
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)

Here's the debug information when connecting to the Windows 11 share:

INFO: Current debug levels:
  all: 256
  tdb: 256
  printdrivers: 256
  lanman: 256
  smb: 256
  rpc_parse: 256
  rpc_srv: 256
  rpc_cli: 256
  passdb: 256
  sam: 256
  auth: 256
  winbind: 256
  vfs: 256
  idmap: 256
  quota: 256
  acls: 256
  locking: 256
  msdfs: 256
  dmapi: 256
  registry: 256
lp_load_ex: refreshing parameters
Initialising global parameters
rlimit_max: increasing rlimit_max (1024) to minimum Windows limit (16384)
INFO: Current debug levels:
  all: 256
  tdb: 256
  printdrivers: 256
  lanman: 256
  smb: 256
  rpc_parse: 256
  rpc_srv: 256
  rpc_cli: 256
  passdb: 256
  sam: 256
  auth: 256
  winbind: 256
  vfs: 256
  idmap: 256
  quota: 256
  acls: 256
  locking: 256
  msdfs: 256
  dmapi: 256
  registry: 256
params.c:pm_process() - Processing configuration file "/etc/samba/smb.conf"
Processing section "[global]"
doing parameter workgroup = MYGROUP
doing parameter server string = Samba Server Version %v
doing parameter log file = /var/log/samba/log.%m
doing parameter max log size = 50
doing parameter security = user
doing parameter passdb backend = tdbsam
doing parameter load printers = yes
doing parameter cups options = raw
pm_process() returned Yes
lp_servicenumber: couldn't find homes
set_server_role: role = ROLE_STANDALONE
Substituting charset 'UTF-8' for LOCALE
added interface eth0 ip=fe80::921b:eff:fe63:ec14%eth0 bcast=fe80::ffff:ffff:ffff:ffff%eth0 netmask=ffff:ffff:ffff:ffff::
added interface eth0 ip=172.17.154.1 bcast=172.17.154.255 netmask=255.255.255.0
Netbios name list:-
my_netbios_names[0]="N30PMDS"
Client started (version 3.6.23-12.el6).
Enter TEST's password: 
s3_event: Added timed event "tevent_req_timedout": 0x7ffc77194bc0
s3_event: Added timed event "tevent_req_timedout": 0x7ffc771951b0
Running timed event "tevent_req_timedout" 0x7ffc77194bc0
s3_event: Destroying timer event 0x7ffc77194bc0 "tevent_req_timedout"
s3_event: Added timed event "tevent_req_timedout": 0x7ffc77194bc0
Connecting to 172.17.154.188 at port 445
s3_event: Added timed event "tevent_req_timedout": 0x7ffc77195a70
s3_event: Destroying timer event 0x7ffc77195a70 "tevent_req_timedout"
s3_event: Destroying timer event 0x7ffc77194bc0 "tevent_req_timedout"
Socket options:
        SO_KEEPALIVE = 0
        SO_REUSEADDR = 0
        SO_BROADCAST = 0
        TCP_NODELAY = 1
        TCP_KEEPCNT = 9
        TCP_KEEPIDLE = 7200
        TCP_KEEPINTVL = 75
        IPTOS_LOWDELAY = 0
        IPTOS_THROUGHPUT = 0
        SO_REUSEPORT = 0
        SO_SNDBUF = 19800
        SO_RCVBUF = 87380
        SO_SNDLOWAT = 1
        SO_RCVLOWAT = 1
        SO_SNDTIMEO = 0
        SO_RCVTIMEO = 0
        TCP_QUICKACK = 1
 session request ok
Substituting charset 'UTF-8' for LOCALE
s3_event: Added timed event "tevent_req_timedout": 0x7ffc77195a10
s3_event: Schedule immediate event "tevent_queue_immediate_trigger": 0x7ffc771924c0
s3_event: Run immediate event "tevent_queue_immediate_trigger": 0x7ffc771924c0
s3_event: Destroying timer event 0x7ffc77195a10 "tevent_req_timedout"
lang_tdb_init: /usr/lib64/samba/en_US.UTF-8.msg: No such file or directory
protocol negotiation failed: NT_STATUS_CONNECTION_RESET

Answer 1

Your CentOS client has an IP address of 172.17.154.1 and is attempting to connect to a server with IP address 172.17.154.188.

This fails because the system at 172.17.154.188 doesn't respond.

It doesn't match the mount command you've given us so it's not possible to diagnose further.