Notre routeur 2621XM fonctionnant sous IOS 12.4 peut aussi faire office de serveur DNS pour notre petit réseau local.

philb@core2:~$ cat /etc/resolv.conf
# Generated by dhcpcd from eth0
# /etc/resolv.conf.head can replace this line
domain philb.net
nameserver 192.168.100.62
# /etc/resolv.conf.tail can replace this line
philb@core2:~$ ping core2.philb.local
ping: unknown host core2.philb.local
philb@core2:~$

Voyons comment configurer un serveur DNS pour la zone philb.local sur notre routeur…

router#configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
router(config)#ip dns server
router(config)#ip host core2.philb.local 192.168.100.49
router(config)#ip host yao.philb.local 192.168.100.50
router(config)#ip host router.philb.local 192.168.100.62
router(config)#ip dns primary philb.local SOA router.philb.local philb.philb.net
router(config)#ip host philb.local ns router.philb.local
router(config)#^Z
router#

Testons ça:

philb@core2:~$ dig router.philb.local.

; <<>> DiG 9.4.3-P4 <<>> router.philb.local.
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 7652
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;router.philb.local.            IN      A

;; ANSWER SECTION:
router.philb.local.     10      IN      A       192.168.100.62

;; Query time: 8 msec
;; SERVER: 192.168.100.62#53(192.168.100.62)
;; WHEN: Wed Feb  3 21:22:16 2010
;; MSG SIZE  rcvd: 52

philb@core2:~$

Et voila !