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Damián_41877's avatar
Damián_41877
Icon for Nimbostratus rankNimbostratus
Jun 13, 2011

SNAT only for outbonding connections to external IP addressess

Hi guys

 

 

I need to create a iRule to SNAT the outbonding connections ONLY when their destination is internet, i.e., when the destination IP address does not belong to the internal addresses (INTRANET):

 

 

10.9.0.0/16 are the INTRANET IP addresses.

 

172.172.172.0/24 are the private IP addresses.

 

200.201.202.0/24 are the (fictitious) PUBLIC IP addresses

 

 

When a *private* node (for instance, 172.172.172.11) tries to open a connection to internet (FTP, wget,...) the company firewall denies. Therefore, I must ask to security team to allow EVERY connection to go out through the firewall.

 

But if those outbonding connections might be originated from a PUBLIC IP address (for instance 200.201.202.5), no request to security team would be needed (because the firewall allows outbonding connections from any PUBLIC node). My idea is use SNAT ONLY in those cases.

 

 

What is the most event suitable event?

 

 

Thanx in advance

 

application delivery
dev
devops
iRules

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  • nitass's avatar
    nitass
    Icon for Employee rankEmployee
    Jun 13, 2011
    can u try this?

     

     

    when CLIENT_ACCEPTED {

     

    if {!([IP::addr [IP::local_addr] equals 10.9.0.0/16]) and \

     

    !([IP::addr [IP::local_addr] equals 172.172.172.0/24]) and \

     

    !([IP::addr [IP::local_addr] equals 200.201.202.0/24])} {

     

    snat X.X.X.X

     

    }

     

    }
  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    Jun 13, 2011
    Or you could add the IP ranges to an address type datagroup and then use the class match command (v10) or matchclass command (v9) to look up the client's destination address:

     

     

    http://devcentral.f5.com/wiki/default.aspx/iRules/class

     

    http://devcentral.f5.com/wiki/default.aspx/iRules/matchclass

     

     

    Aaron
  • Colin_Walker_12's avatar
    Colin_Walker_12
    Historic F5 Account
    Jun 14, 2011
    Generally speaking the class commands (v10) are going to be faster than a multiple if comparison, if performance is an issue. They're also far more scalable.

     

     

    Colin
  • Damián_41877's avatar
    Damián_41877
    Icon for Nimbostratus rankNimbostratus
    Jun 17, 2011
    Thanks everybody

     

     

    The iRule code provided by nitass worked fine!

     

    And the matchclass command also run fine.

     

  • Colin_Walker_12's avatar
    Colin_Walker_12
    Historic F5 Account
    Jun 17, 2011
    Awesome, that's good news. Keep DC in mind if you've got more questions.

     

     

    Colin