I'm trying to set up a domain. It works for vumila.com, but not with www.vumila.com. Here are my files:

db.vumila.com:

```
$TTL    3h
@       IN      SOA     ns1.vumila.com. admin.vumila.com. (
                          2015011601        ; Serial
                          3h       ; Refresh after 3 hours
                          1h       ; Retry after 1 hour
                          1w       ; Expire after 1 week
                          1h )     ; Negative caching TTL of 1 day
;
@       IN      NS      ns1.vumila.com.
@       IN      NS      ns2.vumila.com.

vumila.com.    IN      MX      10      mail.vumila.com.
vumila.com.    IN      A       216.172.176.81
ns1                     IN      A       216.172.176.82
ns2                     IN      A       216.172.176.81
www.vumila.com.                     IN      CNAME       vumila.com.
mail                    IN      A       216.172.176.82
ftp                     IN      CNAME   vumila.com.

```

db.216.172.176:

```
;
; BIND reverse data file for 176.172.216.in-addr.arpa
;
$TTL    604800
176.172.216.in-addr.arpa.      IN      SOA     ns1.vumila.com. admin.vumila.com. (
                          2015011601         ; Serial
                          3h       ; Refresh after 3 hours
                          1h       ; Retry after 1 hour
                          1w       ; Expire after 1 week
                          1h )     ; Negative caching TTL of 1 day
;
176.172.216.in-addr.arpa.       IN      NS      ns1.vumila.com.
176.172.216.in-addr.arpa.       IN      NS      ns2.vumila.com.

82.176.172.216.in-addr.arpa.   IN      PTR     vumila.com.

```

when i dig www.vumila.com i got this:

```
; <<>> DiG 9.9.5-3ubuntu0.1-Ubuntu <<>> www.vumila.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 8352
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;www.vumila.com.            IN  A

;; AUTHORITY SECTION:
vumila.com.     505 IN  SOA ns1.launchpad.com. anb.hotmail.com. 2014122502 7200 7200 172800 38400

;; Query time: 45 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Thu Jan 15 18:48:19 CST 2015
;; MSG SIZE  rcvd: 111

```