Tag Archives: mikrotik

Mikrotik RouterOS – “drop all from WAN not DSTNATed”

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The default DSTNATed firewall rule keeps traffic from the WAN accessing LAN side IP addresses.

More info here

Printing the rules on a router with the default config should show the following.

;;; defconf: drop all from WAN not DSTNATed
chain=forward action=drop connection-nat-state=!dstnat in-interface=ether1

If you are wanting to add the rule to a router, you can copy and past the following command. Replace in-interface=ether with your in interface.

/ip firewall add action=drop chain=forward comment=\ "defconf: drop all from WAN not DSTNATed" connection-nat-state=!dstnat in-interface=ether1

Check if Mikrotik is an Open DNS Resolver

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https://www.openresolver.com

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

Mikrotik hAP – Change SSID via command line

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Problem – Need 2.4 Ghz network enabled and SSID set to WiFi. Wireless router is behind a NAT, using UNMS to ssh into the radio, and from the radio ssh into hAP. Enter/Return key not working to run commands, so running the commands over ssh from the radio.

WA.v8.4.2# ssh admin@192.168.88.2  'interface wireless print'
admin@192.168.88.2's password: 
Flags: X - disabled, R - running 
 0    name="wlan1" mtu=1500 l2mtu=1600 mac-address=74:4D:28:0F:69:B3 
      arp=enabled interface-type=Atheros AR9300 mode=station ssid="MikroTik" 
      frequency=2412 band=2ghz-b/g channel-width=20mhz secondary-channel="" 
      scan-list=default wireless-protocol=any vlan-mode=no-tag vlan-id=1 
      wds-mode=disabled wds-default-bridge=none wds-ignore-ssid=no 
      bridge-mode=enabled default-authentication=yes default-forwarding=yes 
      default-ap-tx-limit=0 default-client-tx-limit=0 hide-ssid=no 
      security-profile=default compression=no 

 1  R name="wlan2" mtu=1500 l2mtu=1600 mac-address=74:4D:28:0F:69:B2 
      arp=enabled interface-type=Atheros AR9888 mode=ap-bridge ssid="WiFi" 
      frequency=5180 band=5ghz-n/ac channel-width=20mhz secondary-channel="" 
      scan-list=default wireless-protocol=802.11 vlan-mode=no-tag vlan-id=1 
      wds-mode=disabled wds-default-bridge=none wds-ignore-ssid=no 
      bridge-mode=enabled default-authentication=yes default-forwarding=yes 
      default-ap-tx-limit=0 default-client-tx-limit=0 hide-ssid=no 
      security-profile=default compression=no 

WA.v8.4.2# ssh admin@192.168.88.2  'interface wireless set disabled=no ssid=WiFi wlan1'
admin@192.168.88.2's password: 
WA.v8.4.2# ssh admin@192.168.88.2  'interface wireless print'
admin@192.168.88.2's password: 
Flags: X - disabled, R - running 
 0    name="wlan1" mtu=1500 l2mtu=1600 mac-address=74:4D:28:0F:69:B3 
      arp=enabled interface-type=Atheros AR9300 mode=station ssid="WiFi" 
      frequency=2412 band=2ghz-b/g channel-width=20mhz secondary-channel="" 
      scan-list=default wireless-protocol=any vlan-mode=no-tag vlan-id=1 
      wds-mode=disabled wds-default-bridge=none wds-ignore-ssid=no 
      bridge-mode=enabled default-authentication=yes default-forwarding=yes 
      default-ap-tx-limit=0 default-client-tx-limit=0 hide-ssid=no 
      security-profile=default compression=no 

 1  R name="wlan2" mtu=1500 l2mtu=1600 mac-address=74:4D:28:0F:69:B2 
      arp=enabled interface-type=Atheros AR9888 mode=ap-bridge ssid="WiFi" 
      frequency=5180 band=5ghz-n/ac channel-width=20mhz secondary-channel="" 
      scan-list=default wireless-protocol=802.11 vlan-mode=no-tag vlan-id=1 
      wds-mode=disabled wds-default-bridge=none wds-ignore-ssid=no 
      bridge-mode=enabled default-authentication=yes default-forwarding=yes 
      default-ap-tx-limit=0 default-client-tx-limit=0 hide-ssid=no 
      security-profile=default compression=no 

WA.v8.4.2# ssh admin@192.168.88.2  'interface wireless registration-table print'
admin@192.168.88.2's password: 
 # INTERFACE           RADIO-NAME       MAC-ADDRESS       AP  SIGNAL... TX-RATE
 0 wlan2                                A7:32:54:EE:E4:35 no  -77dBm... 18Mbps 
 1 wlan2                                34:7A:F4:43:AD:81 no  -69dBm... 6Mbps  

WA.v8.4.2# exit

Mikrotik Safe Mode

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Safe Mode is a configuration fail safe for Mikrotik routers. If enabled and you make a change that disconnects your session to the router, whatever changes were made will be rolled back, which should let you get back in the router.

If your in WinBox you can hit the Safe Mode button at the top left

If your in a telnet or ssh session just hit

ctrl + x

You should see the following to let you know that safe mode is active

[Safe Mode taken]

Hit ctrl + x again to release Safe Mode

Mikrotik RouterOS view and set Simple Queue speeds

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list all simple queues

queue simple print

Print queue that matches part of name

queue simple print where name~"John"

Example results

Flags: X - disabled, I - invalid, D - dynamic 
  0    name="John Smith" target=192.168.1.3/32 parent=none packet-marks="" priority=8/8 queue=sfq-up/sfq-down limit-at=0/0 
       max-limit=1M/10M burst-limit=0/0 burst-threshold=0/0 burst-time=0s/0s bucket-size=0.1/0.1 total-queue=default

Change max speed on queue for client name. The Upload is specified first.

queue simple set max-limit=10M/100M "John Smith"

Setup SNMPv3 on Mikrotik Router

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Setting up SNMP via WinBox is straight forward, the following commands are how to set it up from the command line with some troubleshooting info at the end.

Setup SNMPv3

Setup Community (Change v3Private,encpass, and authpass to their respective names or passwords)

snmp community add name=v3Private encryption-protocol=AES encryption-password=encpass authentication-protocol=SHA1 authentication-password=authpass security=private

Enable and set SNMP community (Trap Community needs to match the above command.  Change contact and the location as needed.)

snmp set contact=admin@incredigeek.com location=DeviceLocation trap-community=V3Private

Troubleshooting

Sometimes, for no apparent reason it seems, routerOS will have issues using the default community.  Work around is to create and use a new community.

Cannot connect with AES encryption

AES doesn’t always seem to work reliably.  Seems to work on some and not other.  Work around is to use DES.

Note that DES is deprecated on newer systems.  For example, you will not be able to read the SNMP details on a router that uses DES from a machine running AlmaLinux 9.  AES seems to be working fine now in 2023.

Log shows Permission Denied

Double check the allowed from addresses, user, and passwords