Unable to Remove Authorized SSH Keys from AirOS

For some reason I ran into an issue where I can not remove authorized SSH Keys in AirOS version 6.3. It redirects to a 404 page and then to the main page.

Attempting to remove SSH keys in AirOS
404 Error while attempting to remove SSH keys

Thankfully, we can still remove the authorized keys from the command line. For more information on making changes over SSH, refer to the following post.

SSH into radio. Replace username and IP address with your radios user and IP.

ssh ubnt@

Open up config file

vi /tmp/system.cfg

Search for the lines that contain

the sshd.auth.key and remove them

Remove the sshd.auth.key lines

Save the file and write the configuration with

/usr/etc/rc.d/rc.softrestart save

Once the command completes, you should be good to go.

Reset UniFi to Factory Defaults – Command Line

SSH into the UniFi. Note that the UniFi username and password get updated from the controller. Refer to here to find username and password.

ssh ubnt@

run the syswrapper.sh script with the restore-default option

syswrapper.sh restore-default

Once the device is reset, log in over ssh and reconfigure.

Note that the username and password will now be ubnt/ubnt

Cambium Routers Command Line Info

Helpful commands. Maybe?

  1. nvram_set
  2. nvram_get
  3. nvram_get 2860 Password

Looks like most of the configuration scripts are in /sbin

Web from the /etc_ro/web/admin/managment.php

                                                                                                                                                                                     <fieldset>                                                                                                                                                                                                                                           <legend><script type="text/javascript">Capture(management.Web_Access)</script></legend>                                                                                                                                                      <table class="setting_block">                                                                                                                                                                                                                        <tr>                                                                                                                                                                                                                                                 <td class="head" id="remoteWebLogin"><script>Capture(management.Remote_Web_Login)</script></td>                                                                                                                                              <td>                                                                                                                                                                                                                                                 <select name="remote_web_login">                                                                                                                                                                                                             <option value="0" <% getCfgSelected("DBID_LAN_LOGIN_ONLY", "1"); %>><script>Capture(share.disable)</script></option>                                                                                                                         <option value="1" <% getCfgSelected("DBID_LAN_LOGIN_ONLY", "0"); %>><script>Capture(share.enable)</script></option>                                                                                                                          </select>                                                                                                                                                                                                                            </td>                                                                                                                                                                                                                                </tr>                                                                                                                                                                                                                                        <tr id="WirelessHostLogin_tr">                                                                                                                                                                                                                       <td class="head" id="WirelessHostLogin"><script>Capture(management.wireless_access_web)</script></td>                                                                                                                                        <td>                                                                                                                                                                                                                                                 <select name="wireless_access_web">                                                                                                                                                                                                          <option value="0" <% getCfgSelected("wireless_access_web", "0"); %>><script>Capture(share.disable)</script></option>                                                                                    <option value="1" <% getCfgSelected("wireless_access_web", "1"); %>><script>Capture(share.enable)</script></option>                                                                                                                          </select>                                                                                                                                                                                                                            </td>                                                                                                                                                                                                                                </tr>                                                                                                                                                                                                                                        <tr  id="web_login_access">                                                                            <td class="head" id="WebLoginWay"><script>Capture(management.way_access_web)</script></td>                                                                                                                                                   <td>                                                                                                                                                                                                                                                 <select name="way_access_web">                                                                                    <!--                                                                                    <option value="https" selected = "selected" <% getCfgSelected("way_access_web", "https"); %>><script>Capture(management.https)</script></option>                                                                                             -->                                                                                                                                                                                                                                          <option value="http" <% getCfgSelected("way_access_web", "http"); %>><script>Capture(management.http)</script></option>                                                                                                                      <option value="http&https" <% gethttphttpsSelected("way_access_web", "http&https"); %>><script>Capture(management.http_https)</script></option>                                                                                              </select>                                                                                                                                                                                                                            </td>                                                                                                                                                                                                                                </tr>                                                                                                                                                                                                                                        <tr id="localport_tr">                                                                                                                                                                                                                               <td class="head"><script>Capture(management.localWeb_Port)</script></td>      

 nvram_get  nvram_set
   nvram_get  [] []
   rt2860_nvram_show - display rt2860 values in nvram
   rtdev_nvram_show   - display 2nd ralink device values in nvram
   show    - display values in nvram for 
   gen     - generate config file from nvram for 
   renew   - replace nvram values for  with 
   clear   - clear all entries in nvram for 
   2860    - rt2860
   rtdev    - 2nd ralink device
           - file name for renew command
 nvram_get show
 nvram_get show 2860

Trying to read data

nvram_get gen file tmp.txt
         nvram_get 2860 lan_ipaddr
 nvram_get 2860 lan_ipaddr
 nvram_get 2860 http_wanport
 nvram_get 2860 http
 nvram_get 2860 httpd
 nvram_get 2860 remote_mgt_https
 nvram_get 2860 remote_mgt
 nvram_get 2860 telnet
 nvram_get 2860 remote_mgt
 nvram_get 2860 remote_ip
 nvram_get 2860 wan_ip

grep “nvram_get 2860” * | grep -i web

grep "nvram_get 2860" * | grep -i web
 check_goahead.sh:DBID_WEB_PORT=nvram_get 2860 DBID_WEB_PORT
 common_lib.sh:  local webport=nvram_get 2860 DBID_WEB_PORT
 common_lib.sh:  local webhttpsport=nvram_get 2860 DBID_WEB_SSL_PORT
 common_lib.sh:  local web_remote_ip=nvram_get 2860 WebRemoteLegalIP
 common_lib.sh:  wireless_access_web=nvram_get 2860 wireless_access_web
 common_lib.sh:  wanwebport=nvram_get 2860 DBID_WEB_PORT
 common_lib.sh:  local webhttpsport=nvram_get 2860 DBID_WEB_SSL_PORT
 common_lib.sh:  lanwebport=nvram_get 2860 lan_webport
 common_lib.sh:  local webport=nvram_get 2860 DBID_WEB_PORT
 common_lib.sh:  local webhttpsport=nvram_get 2860 DBID_WEB_SSL_PORT
 common_lib.sh:  local web_remote_ip=nvram_get 2860 WebRemoteLegalIP
 common_lib.sh:            local teluserpwd=nvram_get 2860 DBID_SUPER_WEB_PASSWORD
 global.sh:webinit=nvram_get 2860 WebInit
 internet.sh:    pass=nvram_get 2860 DBID_SUPER_WEB_PASSWORD
 lan.sh:lan_gw=nvram_get 2860 lan_gateway #for debug, so remote host can access web route from another device in lan port
 nat.sh:webport=nvram_get 2860 DBID_WEB_PORT
 set_ping_rule.sh:       local pinglegaip=nvram_get 2860 WebAclList
 storage.sh:     admPW=nvram_get 2860 DBID_SUPER_WEB_PASSWORD
 storage.sh:     admPW=nvram_get 2860 DBID_SUPER_WEB_PASSWORD
 storage.sh:     admPW=nvram_get 2860 DBID_NORMAL_WEB_PASSWORD
 storage.sh:             admPW=nvram_get 2860 DBID_SUPER_WEB_PASSWORD
 storage.sh:             admPW=nvram_get 2860 DBID_NORMAL_WEB_PASSWORD
 updown_make.sh:         url=nvram_get 2860 websURLFilters
 updown_make.sh:         host=nvram_get 2860 websHostFilters


Not exactly sure if this does work, but seems like it should.


Default status



After running above command

Commit changes

nvram_get commit



Change password

Seems like I am missing a step. Seems to change the password in the nvram, but does not actually change it permanently

Get current password

nvram_get 2860 Password

Set Password

nvram_set Password newpassword

Commit Changes and reboot

nvram_set commit

Helpful links


Uses some of the commands (i.e. nvram_get 2860 HostName )

Ubiquiti set DHCP from command line

Edit the “/tmp/system.cfg”

Change the line that contains “dhcpc.status=disabled” to


add the following lines


Save and exit and save changes

/usr/etc/rc.d/rc.softrestart save

Log into the GUI and verify everything looks correct. Under the network tab it was still showing that it had a static address, although it pulled a DHCP IP.

Ubiquiti AirMax – Set radio to use DHCP from command line

Gain access to radio via ssh

ssh ubnt@

open up the /tmp/system.cfg

vi /tmp/system.cfg

Delete the following line. To move the cursor to the following line and type “dd” and vi will delete the whole line.


Add the following 5 lines. Hit “i” to enter vi insert mode.
br0 should be correct interface in most scenarios.


Save the file by hitting esc and then “:wq” followed by Return/Enter

Save the config changes and reboot the radio so it pulls an address.

/usr/etc/rc.d/rc.softrestart save && reboot

LibreNMS bulk delete

There is a php script in /opt/librenms/ that lets you delete a host from the command line.

sudo /opt/librenms/delhost.php

Replace with the hostname/ip address of the host you want to delete.

Delete Multiple Hosts

First you’ll need to get a list of devices you want to remove.  You can do this by viewing the devices in the LibreNMS MySQL database;


$ mysql -u librenms -p librenms
MariaDB [librenms]> select hostname from devices;
| hostname |
| |
| |
| |
| |
4 rows in set (0.00 sec)
MariaDB [librenms]> exit

Put all the IP addresses you want to remove into a file and run the following for loop.  Replace “remove_ip.lst” with the name of your ip list file.

for i in `cat ~/remove_ip.lst`; do sudo /opt/librenms/delhost.php $i; done

Add, List, and Delete iptable rules

Add iptable rule

The following rule rejects access to port 22 on all devices except ones on the network.  Note the “!”.  This command can be useful for a WHM/cPanel server to limit ssh access.

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

List iptable rules with line numbers

iptables -L --line-numbers

Example output

root@localhost [~]# iptables -L --line-numbers
Chain INPUT (policy ACCEPT)Chain OUTPUT (policy ACCEPT)
num target prot opt source destination
1 REJECT tcp -- ! anywhere tcp dpt:ssh reject-with icmp-port-unreachable

Chain FORWARD (policy ACCEPT)
num target prot opt source destination

Chain OUTPUT (policy ACCEPT)
num target prot opt source destination
1 ACCEPT tcp -- anywhere anywhere multiport dports smtp,urd,submission owner GID match mailman
2 cpanel-dovecot-solr all -- anywhere anywhere

Chain cpanel-dovecot-solr (1 references)
num target prot opt source destination
1 ACCEPT tcp -- anywhere anywhere multiport sports 8984,7984 owner UID match cpanelsolr

Remove iptable rule

To delete a rule use the -D option with the Chain and the line number.  So to delete the first rule in the example output above, we would specify the INPUT chain and the the line number 1

 iptables -D INPUT 1


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.

wget https://dl.ubnt.com/firmwares/XC-fw/v8.4.2/WA.v8.4.2.35930.171017.1722.bin

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 ubntmod.sh 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 ubntmod.sh with the “-U” upgrade option.


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