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Router upgrade?

Discussion in 'Asuswrt-Merlin' started by Scott Kaforey, Dec 7, 2019.

  1. Scott Kaforey

    Scott Kaforey New Around Here

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    I know this past isn't technically Merlin related but hoping you all can help me out. I currently have an ac68. At any given time I have about 70 devices connected to my router. Almost all of them are using static DHCP. I am finding that as I add new devices, I am getting errors because I'm running out of space. I have to shorten the names of the devices. Was wondering if you all have any recommendations, specifically where it would support more devices. I love Asus routers, especially with Merlin, so hoping to stick with them. Any advice would be appreciated!
     
  2. skeal

    skeal Part of the Furniture

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    Create your own naming convention, myself I use initials only.
     
  3. adampk17

    adampk17 Regular Contributor

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    Genuinely curious. Why so many DHCP reservations?
     
  4. Val D.

    Val D. Very Senior Member

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    With so many clients already connected (especially if they are active clients, not just IoT devices) and the need of connecting more, you may have to look at something better than a consumer AIO router. There is a gentleman here at SNB who will be more than happy to help you with professional advice, given you provide the information he needs. Hold on, calling the doctor... @Trip, where are you?
     
  5. Scott Kaforey

    Scott Kaforey New Around Here

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    Just a lot of devices! Computers, phones, TV's, tablets, security cameras, smart devices... It adds up!
     
  6. RMerlin

    RMerlin Super Moderator

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    There are no reasons to put everything on a static lease.
     
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  7. dev_null

    dev_null Occasional Visitor

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    I was initially skeptical, fearing that I would end up with problems, but using the script found here allowed me to free up about 11k of unused NVRAM: https://www.snbforums.com/threads/a...map-device-list-ever-again.60200/#post-528197

    I ran the script, and let the router go for a few days before executing the nvram commit, that way if I had any issues I could just reboot and have all the deleted NVRAM entries back. But I had no issues. At all.

    EDIT: AWM has static entries in 3 different fields, some of these are duplicative. You can check the size of the NVRAM entries with the command: nvram show | awk '{print length(), $0 | "sort -n -r"}' | cut -d"=" -f 1 | head -n 20

    For example, my list of 45 static entries shows these fields all have static dhcp-containing information:

    1818 custom_clientlist
    1470 dhcp_hostnames
    1325 dhcp_staticlist

    Like you I prefer to use static entries to enable reporting and keep track of which devices are what. That way when I have guests I can clearly delineate them from my usual traffic.

    EDIT 2: More info maybe in this thread: https://www.snbforums.com/threads/dhcp_staticlist-and-dhcp_hostnames-utility.58957/
     
    Last edited: Dec 8, 2019
    Scott Kaforey likes this.
  8. adampk17

    adampk17 Regular Contributor

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    Yes, but why not let DHCP do what it’s designed to do and let it manage your IP pool. I can understand a few reservations but they should be the exception.
     
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  9. Scott Kaforey

    Scott Kaforey New Around Here

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    That is what I used to do but when I hit about 40 devices on my network, the network would slow to a crawl and eventually just quit working. A reboot would fix it, and then within a few hours, v it would repeat. I don't remember where, but someone suggested going static DHCP. This instantly fixed the problem and I have been rock solid for about 3 years now issuing this setup. It is also nice to easily be able to tell my known devices from guests.
     
  10. Scott Kaforey

    Scott Kaforey New Around Here

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    Thank you so much, I will definitely look into this!
     
  11. adampk17

    adampk17 Regular Contributor

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    I can only assume that at the time there was something wrong with your router or you had a misbehaving client(s). What you are describing isn’t normal for DHCP.

    If you’re having trouble with DHCP reservation space I guess you could assign IP addresses manually on clients that allow it. Then you wouldn’t need to have them in your reservation list.
     
  12. Scott Kaforey

    Scott Kaforey New Around Here

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    Yeah I thought it was very strange as well. I did factory reset my router and was ready to call it broke when I stumbled across the static DHCP idea. Like I said, it's been rock solid ever since
     
  13. Trip

    Trip Very Senior Member

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    Sorry, I'm late coming from Operating Room #4 - patient had to have a coronary bypass due to an 802.11AX beta-ware packet clot... had to do an emergency EdgeRouter transplant, with PoE switch and multiple APs to cauterize the wound... we lost four liters of type-O packets, but things are stabilized now. I had to hit the scrub sink twice just to clean off all the buffer overflow....

    /doctor parody :D

    @Scott Kaforey - I'd venture you're simply hitting a coded-in limit on DHCP client lease and/or static mapping table size(s). If that's the case, perhaps @RMerlin can work to increase those on his next release, or someone can instruct how to increase those limits via command line or scripts, if possible? Otherwise, I'd look at alternate firmwares with hopefully higher limits; stuff like DD-WRT, Tomato, OpenWRT, etc. For a router replacement, you'd obviously want a different brand all-in-one that doesn't exhibit these limits, or look into an SMB-grade router or firewall distro on DIY hardware. Happy to get into suggestions on the later stuff if you're curious.
     
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  14. RMerlin

    RMerlin Super Moderator

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    Can't, hardcoded by Asus on some models.

    Simply create a dnsmasq.conf.add containing all your extra reservations if for some reason you absolutely need more static leases.
     
    Scott Kaforey likes this.
  15. dev_null

    dev_null Occasional Visitor

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    @RMerlin, if the devices are listed in the dnsmasq.conf.add, may I presume that these are not then stored in NVRAM but rather are dynamically picked up at boot and kept in RAM? If true this would probably meet my needs (and perhaps Scott's needs) for retaining assignments for reporting purposes (while freeing up a few kb of nvram).

    @Scott Kaforey, FWIW based on some additional experimentation, deleting the "custom_clientlist" has no impact on reporting or on IP assignments, because it appears without these entries, the router concatenates the listings in "dhcp_hostnames" and "dhcp_staticlist" instead. (It appears "custom_clientlist" comes from entering devices names from the "network map" device clients view, as opposed to the LAN > DHCP server tab. Entering the device name on the latter saves it to "dhcp_hostnames" from what I can tell.)

    So a "nvram unset custom_clientlist" at the CLI may help free up some NVRAM with no real impact on IP or reporting (RMerlin or others may have some additional insight).
     
    Last edited: Dec 9, 2019
  16. RMerlin

    RMerlin Super Moderator

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    Yes. The file just gets appended to the dnsmasq.conf config file, so just create these entries yourself in the .add file rather than rely on the firmware generating them from the nvram value.
     
    dev_null likes this.