Port Knocking: Difference between revisions
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==Summary== | ==Summary== | ||
This article describes how to use a feature called Port Knocking, to | This article describes how to use a feature called Port Knocking, to improve the security of your | ||
MikroTik device, and minimize a risk of hacking attempts over such protocols like SSH, Telnet, Winbox, etc. | MikroTik device, and minimize a risk of hacking attempts over such protocols like SSH, Telnet, Winbox, etc. | ||
Port knocking is a method that enables access to the router only after receiving a sequenced connection attempts on a set of | Port knocking is a method that enables access to the router only after receiving a sequenced connection attempts on a set of | ||
prespecified closed ports. | prespecified closed ports. | ||
Once correct sequence of the connection attempts is received, the RouterOS | Once the correct sequence of the connection attempts is received, the RouterOS dynamically adds a host source IP to the allowed | ||
address list and You will be able to connect your router. | address list and You will be able to connect your router. | ||
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<p>This example demonstrates how to set your router to use port knocking method:</p> | <p>This example demonstrates how to set your router to use port knocking method:</p> | ||
First firewall rule will store all source ip's which makes connection to router with tcp protocol on port 9000. | The First firewall rule will store all source ip's which makes connection to router with tcp protocol on port 9000. | ||
<pre> | <pre> | ||
/ip firewall filter | /ip firewall filter | ||
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</pre> | </pre> | ||
Second rule adds source ip to "secure" address list only if a host has the same ip address, stored by first firewall rule, | Second rule adds the source ip to "secure" address list only if a host has the same ip address, stored by first firewall rule, | ||
and knocks on tcp port 6000. | and knocks on tcp port 6000. | ||
<pre> | <pre> | ||
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</pre> | </pre> | ||
The third rule is created to accept all connections to the router from "secure" host. | |||
<pre> | <pre> | ||
add chain=input src-address-list=secure action=accept | add chain=input src-address-list=secure action=accept | ||
</pre> | </pre> | ||
Everything else is | Everything else is dropped by this rule. | ||
<pre> | <pre> | ||
add action=drop chain=input | add action=drop chain=input | ||
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==Port knocking== | ==Port knocking== | ||
You can use some of online | You can use some of online available port-knock clients, or manually connect router IP address with defined ports, for example: | ||
Install and use knockd package in linux: | Install and use knockd package in linux: | ||
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{{Note|'''Timeout, ip protocols and ports can be changed regarding your needs.'''}} | {{Note|'''Timeout, ip protocols and ports can be changed regarding your needs.'''}} | ||
Revision as of 07:12, 10 September 2015
Summary
This article describes how to use a feature called Port Knocking, to improve the security of your MikroTik device, and minimize a risk of hacking attempts over such protocols like SSH, Telnet, Winbox, etc.
Port knocking is a method that enables access to the router only after receiving a sequenced connection attempts on a set of prespecified closed ports. Once the correct sequence of the connection attempts is received, the RouterOS dynamically adds a host source IP to the allowed address list and You will be able to connect your router.
Example
This example demonstrates how to set your router to use port knocking method:
The First firewall rule will store all source ip's which makes connection to router with tcp protocol on port 9000.
/ip firewall filter
add action=add-src-to-address-list address-list="port:9000" \
address-list-timeout=1m chain=input dst-port=9000 protocol=tcp
Second rule adds the source ip to "secure" address list only if a host has the same ip address, stored by first firewall rule, and knocks on tcp port 6000.
add action=add-src-to-address-list address-list="secure" address-list-timeout=\
1m chain=input dst-port=6000 protocol=tcp src-address-list="port:9000"
The third rule is created to accept all connections to the router from "secure" host.
add chain=input src-address-list=secure action=accept
Everything else is dropped by this rule.
add action=drop chain=input
Warning: After enabling these firewall rules you will be disconected from the router, and to restore connection, port knocking will be required!
Port knocking
You can use some of online available port-knock clients, or manually connect router IP address with defined ports, for example:
Install and use knockd package in linux:
sudo apt-get install knockd
Knock the router:
knock ''hostname'' ''port1'' ''port2'' ''port3''
Or simply type router ip and port in your web browser:
http://RouterIP:9000/ http://RouterIP:6000/
Note: Timeout, ip protocols and ports can be changed regarding your needs.
Reza Moghadam
--MikroTik Certified Trainer 16:16, 12 April 2013 (UTC)