The RTC in NDS/DSi handhelds forgets the time & date whenever disassembling the console & removing the battery, so I've been wondering to fix the time via internet.
DHCP provides several options for obtaining IP addresses for time server / ntp, and to for obtaining timezone info. I don't know how far it would be recommended to trust that information, or if one would often end up with wrong timezone or nonfunctional server IPs... but I gave it a try... and the result was worse than expected: My router doesn't seem to support any of that DHCP options at all : /
I've added time related options (2, 4, 42, 100, 101) to the list of requested options (via option 55) in the DHCP discover/request messages - and the router does simply ignore that requests. I've tried requesting a handful of other options, which were ignored, too. And tried NOT to request DNS (by removing option 6), which was ignored, too (ie. I still received the DNS address).
The router used is called "o2 HomeBox 6641" (which seems to be rebadged Zyxel hardware). Looking at its internal browser GUI, it does know the correct local time, but it seems to be unwilling to share the time & timezone info via DHCP. So it looks as if I could forget about using the router and DHCP for time. Or is there some trick? Like needing to enable time option requests via another option/version number in the DHCP packet? Or some general rule like always being able to use the router's IP as time server (eg. via 192.168.1.1:port123)?
The other idea would be using a list of known ntp IPs, or somethine called "pool.ntp.org" (which should work as "wildcard" for finding nearby time servers).
The downside would be missing timezone and daylight saving info. And it won't work if the hardcoded servers were shutdown someday.
Hmmmm, or much easier: I could transfer the RTC time from PC to NDS/DSi (alongsides with wifiboto uploads). Thinking about it... at the moment that looks like the best and most reliable method; avoiding all expected and unexpected problems with time servers.
DHCP provides several options for obtaining IP addresses for time server / ntp, and to for obtaining timezone info. I don't know how far it would be recommended to trust that information, or if one would often end up with wrong timezone or nonfunctional server IPs... but I gave it a try... and the result was worse than expected: My router doesn't seem to support any of that DHCP options at all : /
I've added time related options (2, 4, 42, 100, 101) to the list of requested options (via option 55) in the DHCP discover/request messages - and the router does simply ignore that requests. I've tried requesting a handful of other options, which were ignored, too. And tried NOT to request DNS (by removing option 6), which was ignored, too (ie. I still received the DNS address).
The router used is called "o2 HomeBox 6641" (which seems to be rebadged Zyxel hardware). Looking at its internal browser GUI, it does know the correct local time, but it seems to be unwilling to share the time & timezone info via DHCP. So it looks as if I could forget about using the router and DHCP for time. Or is there some trick? Like needing to enable time option requests via another option/version number in the DHCP packet? Or some general rule like always being able to use the router's IP as time server (eg. via 192.168.1.1:port123)?
The other idea would be using a list of known ntp IPs, or somethine called "pool.ntp.org" (which should work as "wildcard" for finding nearby time servers).
The downside would be missing timezone and daylight saving info. And it won't work if the hardcoded servers were shutdown someday.
Hmmmm, or much easier: I could transfer the RTC time from PC to NDS/DSi (alongsides with wifiboto uploads). Thinking about it... at the moment that looks like the best and most reliable method; avoiding all expected and unexpected problems with time servers.