Home / user-965902

Hans van Leeuween's questions

Martin Hope
Hans van Leeuween
Asked: 2022-04-05 07:16:56 +0800 CST
  • 0

My Linux system works with Ubuntu 18.04.6 LTS

A "ps -ef | grep snmpd" gives: Debian-+ 851 1 0 Apr01 ? 00:01:20 /usr/sbin/snmpd -Lsd -Lf /dev/null -u Debian-snmp -g Debian-snmp -I -smux mteTrigger mteTriggerConf -f

The file /var/log/syslog is full of notifications like: Apr 4 11:14:14 system2 snmpd[851]: Connection from UDP: [192.168.0.238]:35386->[192.168.0.7]:161

The file /etc/default/snmpd contains: SNMPDOPTS='-Lsd -Lf /dev/null -u Debian-snmp -g Debian-snmp -I -smux,mteTrigger,mteTriggerConf -p /run/snmpd.pid'

To get less notifications in the file /var/log/syslog, I changed this file to: SNMPDOPTS='-LSwd -Lf /dev/null -u Debian-snmp -g Debian-snmp -I -smux,mteTrigger,mteTriggerConf -p /run/snmpd.pid'

After restarting the snmpd with "systemctl restart snmpd.service", a "systemctl status snmpd.service" show that the snmpd is really restarted.

But a "ps -ef | grep snmpd" still shows the option "Lsd" instead of "LSwd".

Also after a "systemctl daemon-reload".

How can I start the snmpd with the "LSwd" option to get less logging?

snmp
Martin Hope
Hans van Leeuween
Asked: 2021-05-28 07:36:28 +0800 CST
  • 0

I use a Linux system with Ubuntu 18.04.5. Te file /etc/samba/smb.conf contains the rules:

client min protocol = SMB3

and

smb encrypt = required

The command nmap -p445 -Pn -vvv --script smb-protocols on this system gives (between others) the following output:

  Host script results:
  | smb-protocols:
  | dialects:
  | NT LM 0.12 (SMBv1) [dangerous, but default]
  | 2.02
  | 2.10
  | 3.00
  | 3.02
  |_ 3.11

Is that in contrast to each other?

In Samba it is set that the minimum SMB protocol is 3. nmap reports the dangerous SMBv1 protocol anyway.

Can the Ubuntu system still be accessed with SMBv1?

18.04
Martin Hope
Hans van Leeuween
Asked: 2020-10-07 23:07:44 +0800 CST
  • 0

On 6 October2020 on an Ubuntu 16 system with kernel 4.4.0-187-generic, by "unattended-updates", python3-urllib3 1.13.1-2ubuntu016.04.3 is updates to python3-urllib3 1.13.1-2ubuntu016.04.4

After this update Samba doesn't work any more. Registering of the Samba server at the Domain Controller no longer works.

net ads join -U admsamba

Enter admsamba's password: Failed to join domain: failed to lookup DC info for domain 'SAMBA-DOMEIN.LOCAL' over rpc: Undetermined error

From the website below I downloaded the former version python3-urllib3 1.13.1-2ubuntu016.04.3' https://Launchpad.net/ubuntu/xenial/amd65/python3-urllib3

With dpkg I installed the former/correct version 3 over the new/wrong version 4.

#dpkg -i python3-urllib3_1.13.1-2ubuntu016.04.3_all.deb dpkg: warning: downgrading python3-urllib3 from 1.13-1-2ubuntu0.16.04.4 to 1.13.1-2ubuntu016.04.3 (Reading database ... 168370 files and directories currently installed.)

The command below shows that the former version 3 is installed and the new version 4 is available.

apt policy python3-urllib3

python3-urllib3 Installed: 1.13.1-2ubuntu0.16.04.3 Candidate: 1.13.1-2ubuntu0.16.04.4

After the downgrade, it was possible again to register the Samba server at the domain controller.

net ads join -U admsamba

Enter admsamba's password: Using short domain name -- SAMBA-DOMAIN Joined 'system1'to dns domain 'samba-domain.local'

It seems that python3-urllib3 1.13.1-2ubuntu016.04.4 contains a problem. Maybe the security update is to strict.

Do you have the same problem? Wat is the correct channel to report this issue?

python samba
Martin Hope
Hans van Leeuween
Asked: 2020-05-29 00:22:20 +0800 CST
  • 0

I use Ubuntu 18.04.4 If I want to install a specific version of a Ubuntu package, I try the next command: For example:

sudo apt-get install thunderbird=1:68.7.0+build1-0ubuntu0.18.04.1
E: Version '1:68.7.0+build1-0ubuntu0.18.04.1' for 'thunderbird' was not found

Where is apt-get looking for the package 'thunderbird' with version 18.04.1?

Must I download this package before the apt-get install command? If yes, in in which directory should the package be placed? If no, how can I install the last but one version?

package-management apt
Martin Hope
Hans van Leeuween
Asked: 2020-04-01 02:31:30 +0800 CST
  • 1

A Ubuntu 16 server is used as an SFTP-server. This server is located in an DMZ VLAN.

This server must be configured so that:

  • From the external internet only SFTP can be used to login but ssh cannot be used (to start a bash).

  • From the internal network, it must be possible to log in with both SFTP and SSH (to start a bash).

Two sshd can be started for this, each with its own sshd_config file and own port number.

How can a sshd_config be configured in such a way that it is possible to login with SFTP but not with ssh (to start a bash)?

ssh
Martin Hope
Hans van Leeuween
Asked: 2019-11-12 07:46:23 +0800 CST
  • 2

I work with Ubuntu 18.04.3

My current directory is /home/hans/bin, The directory /home/hans/.sshz also exist. My shell is "ksh."

The command cd ../.ssh give the output.

ksh cd: /home/hans/ssh:[No such file or directory]

In this command, the . before ssh disappeared. This problem doesn't occur in the sh and bash shells. This problem also doesn't happen in the "ksh" shell on Centos.

Is this a bug in the ksh shell on Ubuntu?

cd-command ksh
Martin Hope
Hans van Leeuween
Asked: 2019-09-10 00:20:41 +0800 CST
  • 1

I work with Ubuntu 16.04.6 LTS.

On 5 September 2019 apt-get dist-upgrade shows that the next updates were available: libsnmp-base libsnmp30 psmisc snmp snmpd

Before the installation of this update, the snmpwalk command give the following output:

/usr/bin/snmpwalk --v 3 -u <account> -A  <password> 192.168.0.222.1.3.6.1.2.1.25.2.3.1.3

iso.3.6.1.2.1.25.2.3.1.3.1 = STRING: "Physical memory"
iso.3.6.1.2.1.25.2.3.1.3.3 = STRING: "Virtual memory"
iso.3.6.1.2.1.25.2.3.1.3.6 = STRING: "Memory buffers"
iso.3.6.1.2.1.25.2.3.1.3.7 = STRING: "Cached memory"
iso.3.6.1.2.1.25.2.3.1.3.8 = STRING: "Shared memory"
iso.3.6.1.2.1.25.2.3.1.3.10 = STRING: "Swap space"
iso.3.6.1.2.1.25.2.3.1.3.31 = STRING: "/"
iso.3.6.1.2.1.25.2.3.1.3.36 = STRING: "/dev/shm"
iso.3.6.1.2.1.25.2.3.1.3.38 = STRING: "/run"
iso.3.6.1.2.1.25.2.3.1.3.39 = STRING: "/sys/fs/cgroup"
iso.3.6.1.2.1.25.2.3.1.3.58 = STRING: "/boot"
iso.3.6.1.2.1.25.2.3.1.3.59 = STRING: "/home"
iso.3.6.1.2.1.25.2.3.1.3.60 = STRING: "/run/user/1000"

After the update, the snmpwalk command now returns the following output:

iso.3.6.1.2.1.25.2.3.1.3.1 = STRING: "Physical memory"
iso.3.6.1.2.1.25.2.3.1.3.3 = STRING: "Virtual memory"
iso.3.6.1.2.1.25.2.3.1.3.6 = STRING: "Memory buffers"
iso.3.6.1.2.1.25.2.3.1.3.7 = STRING: "Cached memory"
iso.3.6.1.2.1.25.2.3.1.3.8 = STRING: "Shared memory"
iso.3.6.1.2.1.25.2.3.1.3.10 = STRING: "Swap space"

So, the lines with the disk partitions are missing after the update.

Do you have a solution?

Is this expected behavior or a bug?

When this is a bug, what is the official channel to report this?

updates snmp