routing to localhost

[Patrick C]

For reasons unknown, any connections to localhost -- tcp, icmp, or udp -- are 
all originating from my external interface, rl0:


$ telnet localhost 25
Trying ::1...
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Can't assign requested address
telnet: Unable to connect to remote host

IPFW log:
Jul 16 12:46:43 octo ipfw: 100 Accept TCP 192.168.1.119:1434 127.0.0.1:25 out 
via rl0


$ ping localhost
PING localhost (127.0.0.1): 56 data bytes
ping: sendto: Can't assign requested address


$ netstat -rn
Routing tables

Internet:
Destination        Gateway            Flags    Refs      Use  Netif Expire
default            192.168.1.1        UGSc       29      198    rl0
172.16.0.1         00:50:bf:5a:ec:b0  UHLW        0       74    lo0 =>
172.16.0.1/32      link#1             UC          1        0    rl0
172.16.0.2         00:50:bf:5a:ec:b0  UHLW        0      524    lo0 =>
172.16.0.2/32      link#1             UC          1        0    rl0
172.16.0.3/32      link#1             UC          0        0    rl0
192.168.1          link#1             UC          2        0    rl0
192.168.1.1        00:06:25:82:82:49  UHLW       30       12    rl0   1189
192.168.1.119      00:50:bf:5a:ec:b0  UHLW        0       20    lo0


I notice there is no way entry for 127.0.0.1. How can I add one?