Forum Discussion

Nimbostratus

Dec 08, 2014

iRule SMTP Help

I am in need of a little help preventing an open SMTP Relay with the F5. I will give you some background information to the setup. We currently have a pool of 10 servers in our farm and it's currentl...

nitass_89166
Dec 08, 2014
So in an effort to correct this problem, I changed the snat automap in the iRule to reject and drop. This however didn't correct the issue and everyone inside and outside of the data groups can connect.

i think it should work. can you try this?

when CLIENT_ACCEPTED { if { [ class match [IP::client_addr] equals smtp_all_allowed ] } { snatpool smtp_allowed } elseif { [ class match [IP::client_addr] equals smtp_internal_only ] } { snatpool smtp_internal } else { reject } }

nitass

Employee

So in an effort to correct this problem, I changed the snat automap in the iRule to reject and drop. This however didn't correct the issue and everyone inside and outside of the data groups can connect.

i think it should work. can you try this?

when CLIENT_ACCEPTED {  
  if { [ class match [IP::client_addr] equals smtp_all_allowed ] } {
    snatpool smtp_allowed
  } elseif { [ class match [IP::client_addr] equals smtp_internal_only ] } {
    snatpool smtp_internal
  } else {
    reject
  }
}