What is the best way to redirect a specific URL?

[RedScorpion]

I have an older wireless device that tries to sync it’s clock with the manufacturers NTP time server that is no longer functioning properly. Many people have had success redirecting it to look at almost ANY other NTP server. Some have said the they’ve even just used a redirect option that was built into their specific routers parental controls.

What is the best/easiest way to redirect a specific URL in ASUS Merlin?

Basically I want to redirect “old.broken.time.server.com“ to “pool.ntp.org“ or someplace else. I don’t care if the redirect is universal for everything connected to my network or device specific.

 

[dave14305]

In Merlin, enable “Enable local NTP server” and then enable “Intercept NTP client requests” on the Administration / System tab. Or look into the ntpMerlin Addon.

 

[eibgrad]

You can redirect any destination IP (or domain name) to another IP using a DNAT rule in the firewall.

iptables -t nat -I PREROUTING -d old.broken.time.server.com -j DNAT --to 209.51.161.238

 

[eibgrad]

P.S. Got to thinking about this a little deeper. If either of the above techniques works, you can ignore what I have to add below. But it might still be pertinent to someone else w/ a similar problem.

Both the above techniques *assume* the domain name actually resolves to a public IP. But since you didn't mention the domain name specifically (don't know why, it shouldn't be a secret), I have no way to be sure. Just beware, if the clock's DNS query fails, it will never attempt to make a request to any ntp server, local or remote! In that case, it would actually be better to create a DNS record in DNSMasq so that the domain name always resolves, but to your preferred public IP.

address=/old.broken.time.server.com/209.51.161.238

I'm just concerned that at some point (if not now) that domain name will bite the dust too, and not just the ntp service it's supposed to be making available.

Frankly, I'm a bit surprised you even KNOW what domain name it's using given (apparently) you have no means to change it. Not unless the documentation perhaps made this information available, or someone else on the internet was able to determine it somehow. In some cases, devices like this may even be hardcoded w/ an explicit IP just so you can't override it so easily.