doubt on Redirect

[varun]

Hi all,

              When i use REDIRECT policy will the packet be changed 
before to the redirected port number before giving yo the next module 
registered to the same hook?

               If so why is it that the syn packet from LAN goes through 
but syn-ack from internet is dropped by my fw when used with iptables 
(Only for redirect to squid)?

Varun