IPv4 loopback address is missing, why?

[Len Conrad]

>>/etc/hosts :
>>::1 localhost.mydomain.tld localhost
>>127.0.0.1 localhost.mydomain.tld localhost
>>
>>/etc/defaults/rc.conf :
>>ifconfig_lo0="inet 127.0.0.1"   # default loopback device configuration.
>>... but ifconfig always shows no inet:
>>lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
>>         inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3
>>         inet6 ::1 prefixlen 128
>>
>>so we added to /etc/rc.conf :
>>ifconfig_lo0="inet 127.0.0.1 netmask 255.0.0.0"
>>... still not inet4 loopback if (so commented it out).
>>no errors in /var/log/messages,
>>dmesg -a shows no error,
>>... other than services failing to grab ports on 127.0.0.1
>>
>>thanks
>>Len
>
>Do you have network_interfaces set to something different than 
>"auto" in /etc/rc.conf?

I read this thread but missed that some pkg_add added 
network_interfaces in rc.conf, and left out "lo"

thanks, Yuri

Len