Difference between revisions of "Bruteforce login prevention"

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m (Protected "Bruteforce login prevention": will be in manual [edit=sysop:move=sysop])
 
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Stops people trying to bruteforce SSH login
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To stop SSH/FTP attacks on your router, follow this advice.
  
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This configuration allows only 10 FTP login incorrect answers per minute
  
  / ip firewall filter
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in '''/ip firewall filter'''
  add chain=input protocol=tcp dst-port=22 src-address-list=black_list action=drop \
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    comment="drop ssh brute forcers" disabled=no
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  add chain=input protocol=tcp dst-port=21 src-address-list=ftp_blacklist action=drop \
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comment="drop ftp brute forcers"
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add chain=output action=accept protocol=tcp content="530 Login incorrect" dst-limit=1/1m,9,dst-address/1m
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add chain=output action=add-dst-to-address-list protocol=tcp content="530 Login incorrect" \
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address-list=ftp_blacklist address-list-timeout=3h
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This will prevent a SSH brute forcer to be banned for 10 days after repetitive attempts. Change the timeouts as necessary.
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 +
 
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in '''/ip firewall filter'''
 +
 
 +
  add chain=input protocol=tcp dst-port=22 src-address-list=ssh_blacklist action=drop \
 +
comment="drop ssh brute forcers" disabled=no
 +
 
  add chain=input protocol=tcp dst-port=22 connection-state=new \
 
  add chain=input protocol=tcp dst-port=22 connection-state=new \
    src-address-list=ssh_stage3 action=add-src-to-address-list address-list=black_list address-list-timeout=1d \
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src-address-list=ssh_stage3 action=add-src-to-address-list address-list=ssh_blacklist \
    comment="" disabled=no
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address-list-timeout=10d comment="" disabled=no
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  add chain=input protocol=tcp dst-port=22 connection-state=new \
 
  add chain=input protocol=tcp dst-port=22 connection-state=new \
    src-address-list=ssh_stage2 action=add-src-to-address-list address-list=ssh_stage3 address-list-timeout=1m \
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src-address-list=ssh_stage2 action=add-src-to-address-list address-list=ssh_stage3 \
    comment="" disabled=no
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address-list-timeout=1m comment="" disabled=no
  add chain=input protocol=tcp dst-port=22 connection-state=new \
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    src-address-list=ssh_stage1 action=add-src-to-address-list address-list=ssh_stage2 address-list-timeout=1m \
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  add chain=input protocol=tcp dst-port=22 connection-state=new src-address-list=ssh_stage1 \
    comment="" disabled=no
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action=add-src-to-address-list address-list=ssh_stage2 address-list-timeout=1m comment="" disabled=no
  add chain=input protocol=tcp dst-port=22 connection-state=new \
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    action=add-src-to-address-list address-list=ssh_stage1 address-list-timeout=1m comment="" \
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  add chain=input protocol=tcp dst-port=22 connection-state=new action=add-src-to-address-list \
    disabled=no
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address-list=ssh_stage1 address-list-timeout=1m comment="" disabled=no
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If you want to block downstream access as well, you need to block the with the forward chain:
  
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add chain=forward protocol=tcp dst-port=22 src-address-list=ssh_blacklist action=drop \
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comment="drop ssh brute downstream" disabled=no
  
by omega-00 (forum user)
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To view the contents of your Blacklist, go to "/ip firewall address-list" and type "print" to see the contents.

Latest revision as of 10:47, 7 August 2013

To stop SSH/FTP attacks on your router, follow this advice.

This configuration allows only 10 FTP login incorrect answers per minute

in /ip firewall filter

add chain=input protocol=tcp dst-port=21 src-address-list=ftp_blacklist action=drop \
comment="drop ftp brute forcers"

add chain=output action=accept protocol=tcp content="530 Login incorrect" dst-limit=1/1m,9,dst-address/1m

add chain=output action=add-dst-to-address-list protocol=tcp content="530 Login incorrect" \
address-list=ftp_blacklist address-list-timeout=3h


This will prevent a SSH brute forcer to be banned for 10 days after repetitive attempts. Change the timeouts as necessary.


in /ip firewall filter

add chain=input protocol=tcp dst-port=22 src-address-list=ssh_blacklist action=drop \
comment="drop ssh brute forcers" disabled=no

add chain=input protocol=tcp dst-port=22 connection-state=new \
src-address-list=ssh_stage3 action=add-src-to-address-list address-list=ssh_blacklist \
address-list-timeout=10d comment="" disabled=no

add chain=input protocol=tcp dst-port=22 connection-state=new \
src-address-list=ssh_stage2 action=add-src-to-address-list address-list=ssh_stage3 \
address-list-timeout=1m comment="" disabled=no

add chain=input protocol=tcp dst-port=22 connection-state=new src-address-list=ssh_stage1 \
action=add-src-to-address-list address-list=ssh_stage2 address-list-timeout=1m comment="" disabled=no

add chain=input protocol=tcp dst-port=22 connection-state=new action=add-src-to-address-list \
address-list=ssh_stage1 address-list-timeout=1m comment="" disabled=no

If you want to block downstream access as well, you need to block the with the forward chain:

add chain=forward protocol=tcp dst-port=22 src-address-list=ssh_blacklist action=drop \
comment="drop ssh brute downstream" disabled=no

To view the contents of your Blacklist, go to "/ip firewall address-list" and type "print" to see the contents.