only_from and /etc/networks?

I'm probably doing something wrong here, but I seem to be having a problem when trying to use the
only_from option with a network name that's specified in /etc/networks.

Here's /etc/networks:

loopback    127.0.0.0
internal    10.2.32.0
external    10.14.3.0

Here's the xinetd service:

service smtp
{
    socket_type = stream
    protocol    = tcp
    wait        = no
    user        = root
    group       = root
    server      = /usr/sbin/smtpd
    disable     = no
    only_from   = internal
}

I'm not allowed to connect with these messages from xinetd:

03/9/14@22:31:54: FAIL: smtp address from=10.2.32.30
03/9/14@22:31:54: START: smtp from=10.2.32.30
03/9/14@22:31:54: EXIT: smtp status=0 duration=0(sec)

Here's a dump of the service:

Service = smtp
    State = Active
    Service configuration: smtp
        id = smtp
        flags = IPv4
        socket_type = stream
        Protocol (name,number) = (tcp,6)
        port = 25
        Groups = no
        PER_SOURCE = -1
        Bind = All addresses.
        Server = /usr/sbin/smtpd
        Server argv = smtpd
        Only from:  10.2.32.0/255.255.255.255(NET)
        No access: No blocked sites
        Logging to common log file
        Log_on_success flags = HOST DURATION EXIT HOST
        Log_on_failure flags = HOST ATTEMPT
    running servers = 0
    retry servers = 0
    attempts = 0
    service fd = 9

I'm rather curious about the netmask.  Should it have been 255.255.255.0?

Now, I was able to get around it by munging /etc/networks like this:

loopback    127.0.0.0
internal    0.10.2.32
external    10.14.3.0

Am I just going bonkers?

Thanks much,

Leland

Some versions:

xinetd Version 20030122 started with libwrap loadavg options compiled in.
Linux clonixmb 2.4.19-4suse-SMP #3 SMP Fri Sep 12 00:01:42 CDT 2003 s390x unknown
(It's 64-bit in case it matters.)