[SOLVED] Help with one single IP not being able to communicate with default gateway.

[spaceman1861]

Hi,

Im new to proxmox and was hopping to understand and issue I ran into.

I recently purchased 3 old dells and installed proxmox on them all.

I was able to connect them into a cluster but oddly I was unable to update the packages on the first node.

I dove into it and discovered it was unable to ping the default gateway (192.168.1.1).

It should be noted that it could ping other machines in the network and I was able to access the portal on it from other machines in the network.

I added a vm to the node and from that vm was able to ping the default gateway.

I ended up changing its ip from 192.168.0.0 to 192.168.0.3 and it started working fine (after updating the host on the other machines).

My default gateway was setup with 192.168.1.1/24 which I modified to 192.168.1.1/23 but kept the DHCP server range to 192.168.1.1 - 192.168.1.254.

I did this to not upset anything on my existing network.

The hosts on all 3 nodes now look like this

127.0.0.1 localhost.localdomain localhost
192.168.0.3 chopper-0.nodes.jash chopper-0
192.168.0.1 chopper-1.nodes.jash chopper-1
192.168.0.2 chopper-2.nodes.jash chopper-2

With the exception of the address ip being correct the `/etc/network/interfaces` are all the same.

cat /etc/network/interfaces
auto lo
iface lo inet loopback

iface eno2 inet manual

auto vmbr0
iface vmbr0 inet static
        address 192.168.0.2/23
        gateway 192.168.1.1
        bridge-ports eno2
        bridge-stp off
        bridge-fd 0

iface wlo1 inet manual


source /etc/network/interfaces.d/*

I want to understand why `192.168.0.0` wouldn't work, can anyone help me where ?

 

[_gabriel]

192.168.0.0 is not usable for device.
192.168.0.0 is the whole local network address.
keep /24 to be between 192.168.1.1 and 192.168.1.254.
/23 define network between 192.168.0.0 and 192.168.254.0

 

[spaceman1861]

I did not know that. Thanks I feel a bit silly.

I knew about the broadcast IP but not the first one being reserved.

https://en.wikipedia.org/wiki/IPv4#Addresses_ending_in_0_or_255

The first address in a subnet is used to identify the subnet itself. In this address all host bits are 0. To avoid ambiguity in representation, this address is reserved.<a href="https://en.wikipedia.org/wiki/IPv4#cite_note-"><span>[</span>18<span>]</span></a> The last address has all host bits set to 1. It is used as a local broadcast address for sending messages to all devices on the subnet simultaneously. For networks of size /24 or larger, the broadcast address always ends in 255.

Thanks for the for the help