Setting up Proxy over SSH with Putty on Windows

What we are going to do is create a proxy using ssh so we can tunnel our web traffic in Firefox through it.

First, launch putty and setup a SSH connection like you normally would.

Next, in Putty, go to the Connection, SSH, Tunnels.  Set source port, change to Dynamic, and add.  In this example we are using port 1880.

After you have it set, Open the connection and log in.

Now go to the Proxy settings in Firefox.  You can open new tab, type about:preferences, hit enter, search proxy.

Set to Manual proxy configuration, then under SOCKS Host put localhost and the port number from Putty above, 1880 in our case.

You should now be running over the proxy, can test by running a whats my ip address.

This can be particularly useful in cases where you need to access a local IP address range on something like a Ubiquiti radio or router.  Or you need to check something from a different IP address.

Remove AirControl provisioning from Ubiquiti radio via SSH

Short version

List AirControl server(s)


Remove from AirControl Server

mca-provision-rm http://server-address


Expanded Steps

First you’ll need to SSH into your radio


ssh ubnt@

Next run “mca-provision-list” to list the connection(s) the radio has, or is trying to connect to.  If you have had the radio connected to multiple AirControl servers it will show more than one entry.


XM.v6.1.3# mca-provision-list
unknown @ -

To remove, run “mca-provision-rm” with the AirControl address.  You can simple use the “http://server-ip”, shouldn’t have to worry about the port number/AC2/report.


XM.v6.1.3# mca-provision-rm
Found 1 entries matching '':
Removing: unknown @ ...
Found Backup1 on[1] ...
Found Active on[2] ...
Storing Active[1] ... [%100]
Active->Backup[2] ... [%100]


semanage Allow and Delete ports in CentOS

The commands are for CentOS, but should work on Fedora and RedHat.

If semanage is not installed refer to here.

You would typically use this along with the systems firewall to allow a port through.  Guide for firewalld and iptables.  If you change it in the firewall and fail to add/edit it in semanage you can potentially get weird behavior like sshd not wanting to start after changing the port.

Add port

semanage port -a -t ssh_port_t tcp 2222

The above command allows the sshd service to start, using port 2222.

List allowed ports

semanage port -l

You can use grep to filter the results


[admin@localhost ~]# semanage port -l | grep ssh
ssh_port_t tcp 2222, 22
[admin@localhost ~]#

Delete port

semanage port -d -p tcp 2222

Other examples

Allow SNMP

semanage port -a -t snmp_port_t tcp 2222


Setup Secure FTP server on CentOS

Setup SFTP Server

When finished you’ll have a SFTP server setup that is configured so the users are in a chroot environment, and can not ssh, or telnet to the server.

Install SSH server if it is not already

yum install openssh-server openssh-client

Create group that is limited to sftp so they can’t ssh, scp etc.

groupadd sftpusers

Add chroot settings to /etc/ssh/sshd_config.  The %u is a variable, which is the users username.

Match Group sftpusers
ChrootDirectory /sftp/%u
ForceCommand internal-sftp

Make ftp directory

mkdir /sftp

Add SFTP user

useradd -g sftpusers -d /sftp -s /sbin/nologin newsftpuser

Create password for new user

passwd newsftpuser

Create directory for user

mkdir /sftp/newsftpuser

Create directory to put ftp files

mkdir /ftp/newsftpuser/files

Change permissions

chown newsftpuser:sftpusers /ftp/newsftpuser/files/

Restart sshd

systemctl restart sshd

Should be good to go.  Test it by logging in with your favorite FTP client.

SSH Errors

ssh: connect to host port 22: Connection refused

Wrong SSH port.  Check /etc/ssh/sshd_config on linux, or in RouterOS IP->services->SSH

ssh_exchange_identification: Connection closed by remote host

Check the hosts.allow and hosts.deny files. If your getting this error connecting to a Mikrotik check the IP services and the “Available From” addresses.

Allow WHM/cPanel ssh logins from specific IP addresses using iptables

For some reason the hosts.allow and hosts.deny files don’t seem to work on cPanel.  One of the alternative methods to limit ssh logins to specific addresses is to use iptables.

Allow access from specific IP addresses. 

Replace and with your addresses.  You can add more addresses using the “,”.  Also if your ssh port is not the default port, be sure to change it.

iptables -A INPUT -s, -p tcp --dport 22 -j ACCEPT

Reject access from everywhere else

iptables -A INPUT -s -p tcp --dport 22 -j REJECT

You can see your rules with

 iptables -L --line-numbers

If you need to add another rule after the fact, you’ll need to make sure that it is above the REJECT rule. you can use the “-I” to insert it between rules.

Example: inserts rule as the second rule in the INPUT chain

iptables -I INPUT 2 -s -p tcp --dport 22 -j ACCEPT

Install SSH Server on Linux (Debian, Ubuntu, Fedora, CentOS, RedHat)

Debian / Ubuntu

sudo apt-get install -y openssh-server

RPM based Distros, Fedora / CentOS / RedHat

sudo dnf install -y openssh-server

or use yum

sudo yum install -y openssh-server

Start ssh service

sudo systemctl start sshd

By default the SSH service should start when the system starts, but if not try the following command to enable the service on boot up.

Debian / Ubuntu

systemctl enable ssh

Fedora, CentOS, RedHat

systemctl enable sshd

Change SSH port

Not necessary, but it is a good idea to change the default ssh port.  To change the port edit the sshd file.

vi /etc/ssh/sshd_config

If you change the port, you’ll need to allow it in the firewall (firewalld, iptables) and if SELinux is enabled, semanage.

Upgrade Firmware on Ubiquiti Airmax Equipment from the Command Line/SSH

Upgrading the firmware via the command line is super easy.  Basic steps are

  1. Upload firmware file to radio using ftp, scp, or download directly to radio using wget
  2. Move the firmware the /tmp and rename to fwupdate.bin
  3. Upgrade the firmware by running
ubntbox fwupdate.real -m fwupdate.bin

More Detail explanation

Downloading Firmware to Radio

There are a couple of ways to get the firmware uploaded to the radio

  1. Download from Ubiquiti’s website and upload via ftp, scp, filezilla or like
  2. Download directly to the radio using wget

Using wget

ssh into the radio.  Change username and ip address as needed.

ssh ubnt@

cd to the /tmp directory

cd /tmp

Find the firmware file on Ubiquiti’s website, accept the terms, copy the link and paste the link in the terminal after wget.  Replace the below link with the appropriate firmware link.


Installing Firmware

Rename firmware

mv *.bin fwupdate.bin

Start the upgrade

ubntbox fwupdate.real -m fwupdate.bin

The radio will now upgrade and reboot

Another Method.  Using the script

Another way to upgrade a radios firmware from the command line is to use the UBNTMOD tool.  More info on the UBNTMOD script is available here.

Make sure you have the firmware downloaded to your computer and run with the “-U” upgrade option.


bob@localhost:~$ ./ -i -U WA.v8.4.2.35930.171017.1722.bin

Run Speedtest on Ubiquiti Devices from Command Line

This utilizes iperf to test the speed between two Ubiquiti devices.

SSH into first device and start iperf server on one device

iperf -s

SSH into the second device and run the following command to start the speedtest.  Change the ip address to the iperf server ip.

iperf -c -P5

The “-P” Option sets the thread count to 5.  It makes the test a little bit more realistic.


XM.v5.6.9# iperf -c -P5
Client connecting to, TCP port 5001
TCP window size: 16.0 KByte (default)
[  5] local port 51493 connected with port 5001
[  9] local port 51497 connected with port 5001
[  6] local port 51494 connected with port 5001
[  8] local port 51496 connected with port 5001
[  7] local port 51495 connected with port 5001

[ ID] Interval       Transfer     Bandwidth
[  9]  0.0-10.0 sec  4.91 MBytes  4.12 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  6]  0.0-10.0 sec  4.97 MBytes  4.16 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  8]  0.0-10.0 sec  4.86 MBytes  4.08 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  7]  0.0-10.0 sec  4.94 MBytes  4.13 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  5]  0.0-10.0 sec  5.00 MBytes  4.19 Mbits/sec
[SUM]  0.0-10.0 sec  24.7 MBytes  20.7 Mbits/sec


How To export private SSH key on Linux

All that needs to be done is the “id_rsa” key needs to be copied to the “new” host.  You can do this with SCP or sftp.

Example with SCP

The following examples are showing how to export a RSA private key, if your using DSA, then replace id_rsa with id_dsa.

Copy private key from remote server to local machine for the local user

scp root@ ~/.ssh/

Copy private key from localhost to remote host.  This command copies the local users private key to the root user @

scp ~/.ssh/id_rsa root@