Cisco IOS Dynamic DNS

I recently decided to configure dynamic DNS on my Cisco router at home. Lately, my ISP has been giving me issues causing my IP address to change quite often. Since I don’t pay for a static IP, I use dynamic DNS services to map my IP to a DNS name.

I use a free service from dyndns, which lets you pick a domain name to link to your IP. This is most useful for those of us hosting some minor applications behind our routers and we want to connect via a DNS name vs. an IP address that can change.

I usually just go to the website when my IP address changes, but I decided I wanted to let my router do the updating for me.

See sample config below ::

ip ddns update method DYNDNS
HTTP

! put the “a” in brackets <>
add http://username:password@members.dyndns.org/nic/updatesystem=
dyndns&hostname=MYFREE.DNSNAME.XYZ&myip=a

! updates the entry every day
interval maximum 1 0 0 0

interface FastEthernet0/1
description WAN
ip ddns update hostname MYFREE.DNSNAME.XYZ
ip ddns update DYNDNS
ip address dhcp

Cisco link ::
http://www.cisco.com/en/US/docs/ios/12_3/12_3y/12_3ya8/gt_ddns.html

This entry was posted on January 7, 2009 at 5:49 pm and is filed under Routing&Switching, Cisco. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response or trackback from your own site.

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