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FireWall-1 FAQ: How do I enable or block Yahoo Instant Messenger?

Please note: This content was from when I was operating my FireWall-1 FAQ site, which I stopped operating in August 2005. For some reason people still have links to this stuff on the Internet that people are still clicking on.


I am making this information available again AS IS. Given how old this information is, it is likely wildly inaccurate. I have no plans to update this information.


If you're still running versions of Check Point VPN-1/FireWall-1 where this information is still relevant to you, do yourself a favor and upgrade to a more recent release. If you happen to be running a current release and the information is useful, it's by happenstance :)


You will need to block or allow access via port 5050 to the following IP addresses:

  • Yahoo_1 = 24.71.200.68
  • Yahoo_2 = 204.71.202.73
  • Yahoo_3 = 204.71.200.54
  • Yahoo_4 = 204.71.200.55
  • Yahoo_5 = 204.71.200.56
  • Yahoo_6 = 204.71.200.57
  • Yahoo_7 = 204.71.177.35
  • Yahoo_8 = 204.71.202.59
  • Yahoo_9 = 204.71.202.58
  • Yahoo_10 = 216.115.105.214
  • Yahoo_11 = 204.71.201.47
  • Yahoo_12 = 204.71.201.48
  • Yahoo_13 = 216.115.105.215
  • Yahoo_14 = 216.136.172.221
  • Yahoo_15 = 216.115.107.63 es21.msg.yahoo.com
  • Yahoo_16 = 216.115.107.64 es22.msg.yahoo.com
  • Yahoo_17 = 216.115.107.65 es23.msg.yahoo.com
  • Yahoo_18 = 216.115.107.66 es24.msg.yahoo.com
  • Yahoo_19 = 216.115.107.67 es25.msg.yahoo.com
  • Yahoo_20 = 216.115.107.101 es26.msg.yahoo.com
  • Yahoo_21 = 216.115.107.102 es27.msg.yahoo.com
  • Yahoo_22 = 216.115.107.103 es28.msg.yahoo.com
  • Yahoo_23 = 216.115.107.104 es29.msg.yahoo.com
  • Yahoo_24 = 216.115.107.105 es30.msg.yahoo.com
  • Yahoo_25 = 216.136.173.179 es31.msg.yahoo.com

#Cybersecurity Evangelist, Podcaster, #noagenda Producer, Frequenter of shiny metal tubes, Expressor of personal opinions, and of course, a coffee achiever.