Vyacheslav Gapon – personal blog, manuals, articles, notes, development
The appropriate solution I found for running MySQL server on specific IP addresses is to run it at all and then filter the connected clients through iptables.
For the test, I used Ubuntu Server 16.04.5 LTS, which had more than 200 external white IPs and was highly loaded.
I will give an example on Windows 10, on other versions it is essentially the same.
First, open the command line (cmd) on behalf of the administrator and see what modes are currently supported, and whether the Hibernate mode is supported:
Continue reading “Enable or disable Hibernate mode in Windows”
I’ll give an example of the scripts I used before, in the allowip list IP addresses were added to which the Internet is allowed, and in denyip those were redirected to the http page with information about the negative deposit.
Continue reading “Ip-up and ip-down scripts with ipset for Accel-ppp”I noticed once a mistake when installing the application on the Nokia Lumia 530 (RM-1017):
There is a problem completing your request.
Please try again later.
Error code: 80070020
The reason for the error was the wrong date and time, before this error on the phone the battery was removed and they dropped.
So I manually specified the date and time in “Settings” – “Date+Time”, after which the error no longer appeared.
Once after installation ABillS + FreeRADIUS2 + Accel-PPP (ipoe) noticed that for DHCP clients receive only one DNS server.
Access-Accept from FreeRADIUS was this:
Sending Access-Accept of id 1 to 127.0.0.1 port 57481
Session-Timeout = 604800
PPPD-Downstream-Speed-Limit = 51200
Framed-IP-Netmask += 255.255.255.0
Framed-IP-Netmask += 255.255.255.0
Acct-Interim-Interval = 600
DHCP-Domain-Name-Server += 8.8.8.8
DHCP-Domain-Name-Server += 8.8.4.4
PPPD-Upstream-Speed-Limit = 51200
Framed-IP-Address = 172.20.20.20
Finished request 40.
To configure the timeout for SSH sessions, let’s see where the SSH server configuration file is located:
sudo find / -name sshd_config
Open it in any text editor, for example nano:
sudo nano /etc/ssh/sshd_config
Once on the access server, Ubuntu Server 16.04 and Accel-ppp noticed the following messages in the /var/log/kern.log file:
kernel: [365970.550498] HTB: quantum of class 10001 is big. Consider r2q change. kernel: [365970.550547] HTB: quantum of class 10A49 is big. Consider r2q change. kernel: [365979.545580] HTB: quantum of class 10001 is big. Consider r2q change. kernel: [365979.545621] HTB: quantum of class 10BD6 is big. Consider r2q change. kernel: [365995.601973] HTB: quantum of class 10001 is big. Consider r2q change. kernel: [365995.602031] HTB: quantum of class 11705 is big. Consider r2q change.
First I tried to track which interfaces are being raised at this moment:
tail -f /var/log/kern.log | grep "quantum of class 10001 is big" tail -f /var/log/accel-ppp/accel-ppp.log | grep "create interface"
Continue reading “Reason for messages “HTB: quantum of class 10001 is big. Consider r2q change””
Recently, on the WordPress site, I noticed the problem of sending messages via Contact Form 7 from devices with the iOS operating system.
If you used Google reCAPTCHA, when you clicked on the Send button, the page was updated for a very long time and reCAPTCHA reported a wait error, if you disable reCAPTCHA, then the message was sent after 1-2 minutes.
As it turned out, iOS somehow started blocking AJAX, which was used by default when updating the page.
So to solve the problem, I opened the configuration file wp-config.php and just before the line:
define('WP_DEBUG', false);
Added a line:
define ('WPCF7_LOAD_JS', false);
This line prohibits Contact Form 7 from using Javascript.
If you specify this variable at the end of the file, it will not work.
After this, the messages on iOS started to go immediately.
Let’s say that several users are connected through SSH.
First look at the list of online users:
w
Suppose the following information is displayed (where test is the user’s login):
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT test tty1 11:20 1:07 0.03s 0.03s -bash test pts/0 192.168.1.5 11:21 13.00s 0.02s 0.02s -bash test pts/1 192.168.1.3 11:21 0.00s 0.02s 0.00s w
tty1 – it is a client logged in locally, that is, it is located near the computer.
pts/1 – judging for example on IP and WHAT, let’s assume that it’s us, accordingly pts/0 is the client of which we want to disconnect.
See the list of processes and their PID:
ps faux |grep sshd
At me it was displayed:
root 946 0.0 0.5 65508 5368 ? Ss 12:00 0:00 /usr/sbin/sshd -D root 1147 0.0 0.6 92828 6920 ? Ss 12:01 0:00 \_ sshd: test [priv] test 1178 0.0 0.3 92828 3384 ? S 12:01 0:00 | \_ sshd: test@pts/0 root 1192 0.0 0.6 92828 6592 ? Ss 12:02 0:00 \_ sshd: test [priv] test 1223 0.0 0.3 92828 3532 ? S 12:02 0:00 \_ sshd: test@pts/1 test 1248 0.0 0.0 15468 956 pts/1 S+ 12:25 0:00 \_ grep --color=auto sshd
We find test@pts/0 and accordingly 1178 is the required PID.
We terminate the process by specifying its ID, after which the user will immediately disconnect:
sudo kill -9 1178
See also my articles:
Configuring SSH session timeout
Installing and Configuring SSH
In this article I will give examples of some SQL queries for the base of the ABillS billing system.
Continue reading “SQL queries for ABillS”