It's near impossible, most decent routers for instance will not allow IP address that is supposed to be on one side of an interface to talk from the other side of that interface. There is also a problem of getting the spoofed packet to your network in the first place, it has to be routed there.
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chandni D Sent: Tuesday, August 26, 2003 1:58 AM To: [EMAIL PROTECTED] Subject: Re[2]: [IMail Forum] Sorry to be a conspiracy theorist. I too would like to know more on this possibility [of spammers "spoofing" Ip addresses and relaying through our server] We had a similar problem, with some spammer relaying through our sever, despite the 'Relay for IP' setting. We had to switch to the 'No Relay' setting for some time. We assumed the relay was happening due to some 'formmail' exploit. The possibilty of "spoofing" sounds scary. Is there something like that, and if yes, how does one prevent oneself from it? At 12:17 AM 8/26/03 -0400, you wrote: > > Last thing we have saw in our server -we manage Relay for Addreses > > plus SMTP authentication- is that spammers are now spoofing the IP > > addresses. They somehow manage to know what addresses are connecting > > to our server and then start to spoof the address to make the server > > believe that it is from an address that can relay. > >I have to ask you what hard evidence you have that spammers are >connecting from a spoofed (rather than owned) IP address. Remember >that NAT is a mighty tool of the the hacker-spammer. > >-Sandy > > > >------------------------------------ >Sanford Whiteman, Chief Technologist >Broadleaf Systems, a division of >Cypress Integrated Systems, Inc. >e-mail: [EMAIL PROTECTED] >------------------------------------ > > >To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html >List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ >Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/ To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
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