DNCP server reservations


New Around Here
I am seeing an issue with the DHCP server which is preventing me from adding any additional reservations to my RT-AC5300. The device should be able to support 128 reserved address and I currently have about 85. Yesterday I tried to add a new reservation and received an error telling me "the resulting list of DHCP reservations is too long - Remove some or use shorter names". I tried removing a couple of old devices then tried again with the same result. I then tried to shorten the hostname of the device but when I edit the name then try and save the updated list I get the same error.

When I looked at the ASP for the page it appears there are a couple of variables having their length checked before submission and I suspect the issue lies in this check as previously I had run all the way up to 128 reserved addresses without a problem.

I found this in 384.18 and have upgraded to 384.19 bata 2 but the issue exists.

Any suggestions would be appreciated.


Part of the Furniture
This is a long standing and well known problem. Merlin has done his best to maximise the number of possible entries but he is restricted by Asus' limits on the router's nvram variables.

The only way around it (as others have done) is to use a user script to create the reservations, but then you lose the ability to manage them through the GUI.


Senior Member
As @ColinTaylor suggests, use your own scripting. This applies to a LOT of things when it comes the GUI. There are just times when it just doesn't make sense to use the GUI, either due to input field or nvram limitations, or just maintenance purposes (who wants to restore all those items again in the GUI w/ the next firmware upgrade, ugg). Same issue applies to certs/key w/ OpenVPN, only it's worse given the typical size of these items. Store them in jffs and reference them in the custom config field.


Very Senior Member
I'd also question the use of a home router in this situation. Or at least question why you need so many mappings.

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