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Static DHCP mapping issues

Discussion in 'Asuswrt-Merlin' started by Denko, Nov 15, 2019.

  1. Denko

    Denko New Around Here

    Joined:
    Nov 15, 2019
    Messages:
    3
    I have an RT-86U and because of various reasons ended up starting to use Merlin on it. Works ok'ish but lately I haven't been able to add anymore DHCP mapped devices (may have been the latest firmware or one before that.) Once I hit update the DHCP table it just sits there for ever and if I try to connect again the whole webserver on the router is gone (some other pages on the wifi side experience the same thing. Obviously the change doesn't take) I have about 30 in the list... and I believe I saw somewhere the limit was ~256.

    Note that the device (2nd of my RT-86U and both have the same issue) does not work on the 2.4 GHz band in any shape way or form.

    Anyhow... what info am I missing? Is the DHCP mapping expected to be like that?
     
  2. ColinTaylor

    ColinTaylor Part of the Furniture

    Joined:
    Mar 31, 2014
    Messages:
    9,798
    Location:
    UK
    No, the size of the list is is severely limited, especially on the RT-AC86U. What firmware version are you running? There was a change in 384.13 that increased the size of the list.

    Code:
    384.13 (31-July-2019)
      - CHANGED: dhcp_staticlist no longer contains hostnames, these
                 have been moved to dhcp_hostnames for better
                 compatibility with upstream and closed source
                 components, also allows more static leases to be
                 defined before reaching the size limit.
     
    EventPhotoMan likes this.
  3. Denko

    Denko New Around Here

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    Nov 15, 2019
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    I am using the firmware for RT-AC86U @ 384.13.0 Can you elaborate on "especially on the RT-AC86U" as I need a couple of more reasons before I throw my two units into the garbage.
     
  4. ColinTaylor

    ColinTaylor Part of the Furniture

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    Location:
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    Using 384.13 I would have thought you would be OK. The very early firmware versions only allowed for very small lists (~35 IIRC). Merlin increased that so prior to 384.13 the number of entries was about 70 (assuming fairly short host names). With 384.13 it has increased again.

    It's possible that the conversion from the old way of storing the names to the new got screwed up somewhere. @Xentrk has written a utility that can backup, restore, clear, size check, and even increase the DHCP entries.

    https://www.snbforums.com/threads/dhcp_staticlist-and-dhcp_hostnames-utility.58957/
     
  5. EventPhotoMan

    EventPhotoMan Senior Member

    Joined:
    Mar 29, 2018
    Messages:
    457
    Yes you really need a clean slate install. I’ve had no issues with much more static bonded clients.
     
  6. PolarBear

    PolarBear Regular Contributor

    Joined:
    Apr 14, 2015
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    191
    Location:
    North of the Alps
    And maybe make sure that the host names do not contain any illegal characters.

    Some characters are problematic (there was a thread about this somewhere).

    I use only letters, numbers and minus signs and that works ok for me.
     
  7. Denko

    Denko New Around Here

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    Nov 15, 2019
    Messages:
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    Thanks for all the replies. I factory reset it and reconfigured everything from scratch. It seems to work a whole lot better now. Cheers!