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change subnet mask in network - change everywhere?

Discussion in 'Other LAN and WAN' started by busch09, Mar 2, 2019.

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  1. busch09

    busch09 Occasional Visitor

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    May 6, 2013
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    Hi,

    I changed my subnet mask on my gateway to 255.255.252.0. I have a couple of managed switches as well devices with static IPs.

    Do I have to change the subnet mask to 252 in every switch and every device?

    Here is where I am stuck right now (all Asus on Merlin 384.9):
    I have change my WAN router Ac3100 to 192.168.1.1, 255.255.252.0 with DHCP fro 192.168.3.2 to 192.168.3.254, Gateway 192.168.1.1, Primary DNS 192.168.1.1.

    DHCP assigns IP in 192.168.3.x now and I can ping everything yet in my network map a lot of clients are missing, bot in the 168.1.x and 168.2.x subnets.
    I have two additional Asus Ac68 as APs 192.168.1.2, 192.168.1.3 both with 255.255.252.0 and gateway&DNs to 192.168.1.1.
    These do not show any 192.168.3.x IPs at all in the network map client list.

    anyone know how to fix this so the clients lists list all clients in 192.168.0.1 and 192.168.3.254?
     
    Last edited: Mar 2, 2019
  2. coxhaus

    coxhaus Part of the Furniture

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    It depends on whether the IP address is within the original mask range or not. The mask is limiting the IP range.
     
  3. ColinTaylor

    ColinTaylor Part of the Furniture

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    Normally, yes. But that's not the cuase of your problem.

    This is a long standing and well known limitation of the Network Map. It only works with subnets of 255.255.255.0. And before you ask ;); No, Merlin can't fix it. The Network Map code is closed-source so only Asus can fix it.
     
  4. busch09

    busch09 Occasional Visitor

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  5. sfx2000

    sfx2000 Part of the Furniture

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    it should - you just won't see it in the Asus Network map - seems that it's hardcoded for /24...

    Code:
    ipcalc 192.168.0.0/255.255.252.0
    Address:   192.168.0.0          11000000.10101000.000000 00.00000000
    Netmask:   255.255.252.0 = 22   11111111.11111111.111111 00.00000000
    Wildcard:  0.0.3.255            00000000.00000000.000000 11.11111111
    =>
    Network:   192.168.0.0/22       11000000.10101000.000000 00.00000000
    HostMin:   192.168.0.1          11000000.10101000.000000 00.00000001
    HostMax:   192.168.3.254        11000000.10101000.000000 11.11111110
    Broadcast: 192.168.3.255        11000000.10101000.000000 11.11111111
    Hosts/Net: 1022                  Class C, Private Internet
    
     
    L&LD likes this.
  6. coxhaus

    coxhaus Part of the Furniture

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    I see no reason to use a 22 bit mask at home unless you are using multiple networks and you want to super scope your networks.
     
  7. sfx2000

    sfx2000 Part of the Furniture

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    I agree...

    Nice that my WAN provider does give an expanded scope, doesn't mean it works ;)
     
    L&LD likes this.