Active and passive FTP mode

FTP can work both in the active mode and in the passive mode.

In active mode, the client performs a control connection with the server, and the server makes a connection to the client for data transfer.
The passive control connection and data connection are made by the client himself.

Under the control connection is meant authentication and command transmission.
The control connection is executed by the client in both cases equally, from the client side from the dynamic TCP port 1024-65535 to the server port 21.

In the active mode after the control connection from the client, the FTP server connects to the client’s dynamic port 1024-65535 from its TCP port 20 for data transfer.
In the passive mode after the control connection from the client, the FTP server tells the client the number of the dynamic TCP port 1024-65535 to which it can be connected to the client for data transmission.

Speed limit on Ubiquiti devices

Suppose we need to limit the speed on the client antenna.
Accordingly, it is in the station mode and is connected to the access point.

For restriction, we go to the web-based antenna management interface, open the Network tab, change the Configuration Mode: to Advanced, which will bring more parameters that you can configure .

At the very bottom, click on Traffic Shaping, check the Enable checkbox and specify the desired speed limit for WLAN0 or LAN0.
For example, you need to limit the reception speed to 5Mb/s and send up to 512Kbps, for reliability, we’ll specify a limit for both network interfaces, where Ingress is specified for WLAN0 5120, and for LAN0 512, respectively, for Egress, vice versa, WLAN0 – 512, and LAN0 – 5120, burst is left unchanged, that is, 0.

To apply the changes click below Change and then above Apply, after which the antenna configuration will reboot.

On the access point, alas, you can not limit the speed for each client, if you do the above settings (in reverse order), then the overall speed for all clients will be limited. In this case, you can cut the speed, for example billing, by turning on the Advanced tab Client Isolation in the Advanced tab so that clients do not see each other on the network and do not exchange traffic.

Done.

Configuring ACL on Ubiquiti devices

Let’s say we want to configure the ACL (access control list) on the Ubiquiti access point.

In the web interface of the device, open the tab “Wireless“.

At the very bottom opposite “MAC ACL:” tick the “Enable“.

And choose “Policy:“, on “Allow” (means that there will be devices on the list that are allowed to connect, all who are not registered – can not) or “Deny” (in the list of devices that can not be connected, and everyone else can).

By clicking on the button “ACL…“, in the opened window to add the device, in the first field we indicate its MAC, in the second one any desired description and click “Add“, later “Save“.
And the last stage is at the top click the button “Apply“, after which the changes are saved and applied without loss of communication with the device (without rebooting).

Resetting the iLO password via hponcfg on HP servers

On the test, I change the iLO password to the standard Administrator user on the HP ProLiant DL380 G7 server, the password is generated randomly from the manufacturer and installed in the BIOS, it can also be seen on the pull-out ribbon and attached to the server.

Therefore, in order not to restart the server to change the password, create a file with the name reset_password.xml for example and add content to it:

<RIBCL VERSION="2.0">
<LOGIN USER_LOGIN="Administrator" PASSWORD="password">
<USER_INFO MODE="write">
<MOD_USER USER_LOGIN="Administrator">
<PASSWORD value="password specify here only"/>
</MOD_USER>
</USER_INFO>
</LOGIN>
</RIBCL>

Where Administrator, this is the user name, password – do not touch, there can be any text, but only indicate the desired password to the user in the PASSWORD value.

We export the file:

sudo hponcfg -f reset_password.xml

In case of an error, you can output the report to the log.txt file with the command:

sudo hponcfg -f reset_password.xml -l log.txt

See also:
Configuring iLO through hponcfg

Using the acct utility

The acct utility allows you to see statistics of user activity in the system.

Installation in Ubuntu:

sudo apt-get install acct

Removed in Ubuntu with the following command:

sudo apt-get remove acct

Installation in Fedora:

su -c 'yum install psacct'

Running in Ubuntu:

/etc/init.d/acct start

Running in Fedora:

su -c 'service acct start'

I will list and describe several commands of the acct utility:
ac – statistics on the time spent by users in the system
ac -d (per day)
ac -y (in a year)
ac -p (individual statistics)
ac –version (display version of the utility)
man ac (help on the team)

sa – information about executed commands and running applications
sa -c (statistics in percent)
man sa (help on the command)

lastcomm – last executed commands
sudo accton on/off – on and off collection of information

Troubleshooting and Error 0x00000005 after Windows Update from 14.08.13

After installing the Windows updates from August 14, 2013 many users stopped running many applications with the output of the error 0x00000005 or even the operating system stopped loading. In particular, Windows 7 x64. The cause was the installation of the update KB2859537. To fix the error, you can remove it by typing the command:

wusa.exe /uninstall /kb:2859537

09/11/2013 one more update has been issued that causes the same symptoms, we also treat with the removal:

wusa.exe /uninstall /kb:2872339