Search for “Turn Windows features on or off” and launch
Find “Windows Sandbox” and enable and hit OK. After it installs you’ll need to reboot.
After you reboot you can search and launch the Windows Sandbox
Enable Windows Sandbox
Reply
UBNTMOD check range of IP addresses and see if they resolve DNS
The following uses the ubntmod.sh script to check a device then report if it is resolving DNS or not. ip=”192.168.1.” specifies the first part of the ip, the “for ((i=1; i<=254;i++))” tells it to go from 192.168.1.1 – 192.168.1.254, change the beginning and ending number if you want to change the ip range.
ip="192.168.1." && for ((i=10; i<=30;i++)); do if ( fping ${ip}$i -r1 | grep alive); then ./ubntmod.sh -i ${ip}${i} -e ; else echo ${ip}$i not alive; fi ; done
Broken out for easier reading.
ip="192.168.1."for ((i=10; i<=30;i++))doif ( fping ${ip}$i -r1 | grep alive); then./ubntmod.sh -i ${ip}${i} -eelse echo ${ip}$i not alivefidone
If the script is able to log into the device and resolve DNS you should get
192.168.1.1 Resolves DNS
Installing LineageOS 17 Android 10 on Pixel
Download twrp from here
Download LineageOS 17 from here
Boot phone to boot menu then fastboot twrp
sudo fastboot boot Downloads/twrp-3.3.0-0-sailfish.img
Wipe to factory defaults
Side load LineageOS Android 10 from the Advanced page on TWRP
adb sideload Downloads/lineage-17.0-withMTG-20191217-UNOFFICIAL-sailfish.zip
Reboot and setup.
Linux, Send USR1 signal to pid
In Linux you can send signals to a process id to trigger actions for the program. Useful scenario for this is to renew an IP address on a device that uses udhcpc. You should be able to change udhcpc for other programs, you’ll just need to read the help for that specific program.
In the udhcpc help it says
Signals:
USR1 Renew lease
USR2 Release lease
But how do we send those signals to udhcpc? Answer, use the kill command.
kill: kill [-s sigspec | -n signum | -sigspec] pid | jobspec … or kill -l [sigspec]
Send a signal to a job.
Send the processes identified by PID or JOBSPEC the signal named by SIGSPEC or SIGNUM. If neither SIGSPEC nor SIGNUM is present, then SIGTERM is assumed.
Options:
-s sig SIG is a signal name
-n sig SIG is a signal number
-l list the signal names; if arguments follow `-l' they are
assumed to be signal numbers for which names should be listed
-L synonym for -l
Kill is a shell builtin for two reasons: it allows job IDs to be used instead of process IDs, and allows processes to be killed if the limit on processes that you can create is reached.
Exit Status:
Returns success unless an invalid option is given or an error occurs.
We see from above that we can pass a signal name in using the -s option.
So to send USR1 signal to udhcp we do the following
kill -s USR1 pid_of_udhcpc
Replace pid_of_udhcpc with the actual pid or use the following command to find the pid
kill -s USR1 $(pgrep udhcpc)
“pgrep udhcpc” prints the pid of the searched for process.
Helpful links
https://www.thegeekstuff.com/2011/02/send-signal-to-process/
https://www.linux.org/threads/kill-signals-and-commands-revised.11625/
Ubiquiti – Renewing DHCP client lease from command line
AirOS uses udhcpc for the DHCP client on Ubiquiti Radios. To renew the DHCP address you can kill the udhcpc process and it’ll automatically restart and get a new address.
Renew DHCP lease
Kill udhcpc with the following command.
killall udhcpc
Other info
Print info about the DHCP lease. May need to change “info.br1” to “info.eth0” or some other interface.
cat /etc/udhcpc/info.eth0
Example output.
XW.v6.2.0# cat /etc/udhcpc/info.br1 u_interface="br1" u_broadcast="" u_subnet="255.255.255.0" u_ip="10.93.0.10" u_router="10.93.0.1" u_dns="8.8.8.8 1.1.1.1" u_hostname="" u_serverid="10.93.0.1" u_domain="" u_leasetime=600 u_timestamp="1143249941" u_started=1142593 u_pid=936 XW.v6.2.0#
Command arguments that udhcp is run with. Info was collected by running the “ps | grep udhcp” command. Note that the interface “eth0” can be different if the device is in bridge mode.
/sbin/udhcpc -f -i eth0 -s /etc/udhcpc/udhcpc -p /var/run/udhcpc.eth0.pid -h device_name
udhcpc help output
XW.v6.2.0# udhcpc --help
BusyBox v1.24.2 (2019-07-03 11:13:35 EEST) multi-call binary.
Usage: udhcpc [-fbqvRB] [-t N] [-T SEC] [-A SEC/-n]
[-i IFACE] [-s PROG] [-p PIDFILE]
[-oC] [-r IP] [-V VENDOR] [-F NAME] [-x OPT:VAL]... [-O OPT]...
-i,--interface IFACE Interface to use (default eth0)
-s,--script PROG Run PROG at DHCP events (default /usr/share/udhcpc/default.script)
-p,--pidfile FILE Create pidfile
-B,--broadcast Request broadcast replies
-t,--retries N Send up to N discover packets (default 3)
-T,--timeout SEC Pause between packets (default 3)
-A,--tryagain SEC Wait if lease is not obtained (default 20)
-n,--now Exit if lease is not obtained
-q,--quit Exit after obtaining lease
-R,--release Release IP on exit
-f,--foreground Run in foreground
-b,--background Background if lease is not obtained
-S,--syslog Log to syslog too
-r,--request IP Request this IP address
-o,--no-default-options Don't request any options (unless -O is given)
-O,--request-option OPT Request option OPT from server (cumulative)
-x OPT:VAL Include option OPT in sent packets (cumulative)
Examples of string, numeric, and hex byte opts:
-x hostname:bbox - option 12
-x lease:3600 - option 51 (lease time)
-x 0x3d:0100BEEFC0FFEE - option 61 (client id)
-F,--fqdn NAME Ask server to update DNS mapping for NAME
-V,--vendorclass VENDOR Vendor identifier (default 'udhcp VERSION')
-C,--clientid-none Don't send MAC as client identifier
-v Verbose
Signals:
USR1 Renew lease
USR2 Release lease
XW.v6.2.0#
Note that you can also send a signal to the PID of udhcpc and have it renew the address. To do that use the following command, replacing pidofudhcpc to pid of udhcp.
kill -s USR1 pidofudhcpc
or use the following command to find the pid for you.
kill -s SIGUSR1 $(pgrep udhcpc)
Check if Mikrotik is an Open DNS Resolver
You can test if a router is acting as an open DNS resolver by running the following command from a Linux terminal. If you need to install dig, refer to here for Debian/Ubuntu and here for RPM/CentOS/Fedora Distros.
Replace 192.168.88.1 with the host you want to test against.
dig +short test.openresolver.com TXT @192.168.88.1
If you receive the following
"open-resolver-detected"
The router is acting as an open resolver.
If you get
;; connection timed out; no servers could be reached
Then you are unable to use that router to resolve DNS.
Example running the command against a Mikrotik router with Remote DNS turned on Then adding a firewall rule to block unwanted request.
bob@localhost:~$ dig +short test.openresolver.com TXT @192.168.88.1 "open-resolver-detected" bob@localhost:~$ <<-- Put firewall rule on router -->> bob@localhost:~$ dig +short test.openresolver.com TXT @192.168.88.1 ;; connection timed out; no servers could be reached bob@localhost:~$
Extra notes
If you have firewall rules allowing your IP address to use the router for DNS, then the above command to test will show it as an Open Resolver. Ideally you would want a connection from the outside to test. Or you can use this link and test it from the website. https://www.openresolver.com
Install dig on CentOS
The dig command is apart of the bind-utils package. You can install it with.
sudo yum install bind-utils -y
Now run dig
dig localhost
Install Microsoft Teams Preview on Linux
Download the correct package for your distribution of Linux from
https://teams.microsoft.com/downloads
You should be able to open the installer and it should install, if not you can run the following commands from a terminal
The install instructions are for Debian/Ubuntu/Linux Mint.
Install using dpkg
sudo dpkg -i Downloads/teams_1.2.00.32451_amd64.deb
Launch Teams by typing
teams
Or you can launch it from your Applications Menu
After Teams is installed and launched, sign in to your Microsoft account.
DD show show status of progress
You can have dd show the progress of a write by specifying “status=progress” in the command line arguments.
sudo dd if=Downloads/CentOS-8-x86_64-1905-boot.iso of=/dev/sdb status=progress
Example:
bob@localhost:~$ sudo dd if=Downloads/CentOS-8-x86_64-1905-boot.iso of=/dev/sdb status=progress 559690240 bytes (560 MB, 534 MiB) copied, 96 s, 5.8 MB/s <-- This is shown while writing. 1093632+0 records in 1093632+0 records out 559939584 bytes (560 MB, 534 MiB) copied, 96.0339 s, 5.8 MB/s
no matching key exchange method found. Their offer: diffie-hellman-group1-sha1
Work around is to use the -o option and specify KexAlgorithms with the correct option.
ssh -o KexAlgorithms=+diffie-hellman-group1-sha1 admin@192.168.11.1
List of errors from devices
The following are errors that are returned when trying to ssh to a device.
Cambium 450i PMP Equipment
Unable to negotiate with 192.168.0.1 port 22: no matching key exchange method found. Their offer: diffie-hellman-group1-sha1,diffie-hellman-group14-sha1