to be honest i'm not seeing that at all. can you show an example output containing this replication? note that as it's a single interface, lo will be sending and recieving between itself. if i do a telnet to localhost i see
[root@kermit ~]# tcpdump -i lo
17:21:20.038428 IP localhost.localdomain.49645 > localhost.localdomain.telnet: S 1657860734:1657860734(0) win 32792 <mss 16396,sackOK,timestamp 120682619 0,nop,wscale 6>
17:21:20.038812 IP localhost.localdomain.telnet > localhost.localdomain.49645: R 0:0(0) ack 1657860735 win 0
which doesn't have any replications as fasr as a take your use of it to be.