NetBIOS resolution not working via lookup, ping etc., but nmblookup works

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1

Hi all,
what can be the reason why ping, nslookup and other tools (not to mention implicit name resolution, i.e. by providing a NetBIOS name to a browser) doesn’t work when nmblookup works fine?

I’m running Ubuntu 22.04 with kernel 5.15.

I have a machine called t2gst1uk which runs on 192.168.200.5. nmblookup reports this correctly:

# nmblookup t2gst1uk
192.168.200.5 t2gst1uk<00>

However, when using ping, this fails:

 ping t2gst1uk
ping: t2gst1uk: Temporary failure in name resolution

A winbindd is running:

[global]
workgroup = WORKGROUP
netbios name = XCHANGE
disable netbios = no
wins support = yes
name resolve order = bcast wins lmhosts

and the /etc/nsswitch.conf looks like this:

# /etc/nsswitch.conf
#
# Example configuration of GNU Name Service Switch functionality.
# If you have the `glibc-doc-reference' and `info' packages installed, try:
# `info libc "Name Service Switch"' for information about this file.

passwd:         files systemd
group:          files systemd
shadow:         files
gshadow:        files

hosts:          files wins dns
networks:       files

protocols:      db files
services:       db files
ethers:         db files
rpc:            db files

netgroup:       nis

Additionally, this worked fine unter Ubuntu 14.04. (yes, way old). All the settings are the same.

What is going on? What additional info might I provide so solve this problem?

BR
Karim

2

NSS needs a library for each Name Service it’s supposed to use. In the case of winbind / wins that should be libnss_winbind.so2 and libnss_wins.so.2 both of which should be in the package libnss_winbind. Do you have that package installed ?

1 Like
3

Yes, I have:

ii  libnss-winbind:amd64                   2:4.15.13+dfsg-0ubuntu1.8               amd64        Samba nameservice integration plugins

Why doesn’t it work?

BR
Karim

4

Sorry to reply to myself here.

Is there any reason why a DNS inquiry would not use the libs included in libnss-winbind?

As I mentioned, nmblookup works fine; it’s just the name resolution of Linux which doesn’t find name shared via NetBIOS messages.

BR
Karim