cluster network IP management

[nicolasdiogo]

hi,

i understand that each pve nodes has an external IP having a range of say:
192.168.1.nnn
where 1<= nnn <= 254

thus in a cluster envrionmnet each node would be like:
192.168.1.1
192.168.1.2
..
192.168.1.254

and that each node also has an internal private IP range, normally:
10.0.0.0/8

is this managed by PVE on a cluster-wide base or each node works individually?

would there be a risk of having two VMs on different nodes running with the same IP?
as this would not allow for VM migration.

also, in this network range (10.0.0.0/8) are VMs able to connect to each other on different nodes?
how are these IPs created and managed by PVE, i checked the dhcpd.conf and found no info there.

i have not found ths information on the wiki; maybe a more experienced user could throw alight on these questions?

many thanks,

Nicolas

 

[udo]

Hi,
you are right with the first part: each cluster-node need to be in the same network.

If you want to use more than one network, which are interconnected between the clusternodes you should use a second bridge, like vmbr1 or vmbr50 (for vlan 50). On this bridge, the clusternodes need no ip - it's enough to use an IP on the guest.
For a second bridge you need a dedicate NIC on each proxmox-server, or work with vlan-tagging (and need a 802.1Q-ready switch). If you don't have the second network allready, you also need the infrastructure for that (router, perhaps dhpc-server, and so on).

Udo

 

[nicolasdiogo]

many thanks Udo,

so i do require two NICs on each host:
- vmbr0 - connecting each node to each other and supporting proxmox via network 192.168.1.xxx
- vmbr1 - connection between VMs, node does not require IP on this NIC; VMs will have IP in range 10.0.0.0/8

i beleive i understand the topology of the network now.

but how do i manage/edit the IP numbers of these VMs.
would i then need to create a VM with a DHCP Server for this network - and if so would it not clash with proxmox dhcp offering?

thanks,

 

[udo]

Hi,

many thanks Udo,

so i do require two NICs on each host:
- vmbr0 - connecting each node to each other and supporting proxmox via network 192.168.1.xxx
- vmbr1 - connection between VMs, node does not require IP on this NIC; VMs will have IP in range 10.0.0.0/8

i beleive i understand the topology of the network now.

but how do i manage/edit the IP numbers of these VMs.
would i then need to create a VM with a DHCP Server for this network - and if so would it not clash with proxmox dhcp offering?

thanks,

yes, you need the infrastucture for this network (dhcp-server router...). It's a independent network, so you can choose a ip-range do you like (normaly of course private IPs). If the proxmox-host hasn't an IP on vmbr1 you can't get trouble with the internal NAT-range. But you can also choose 192.168.2.0/24.

Udo

 

[nicolasdiogo]

thanks Udo,

i decided to use network:

20-bit block 172.16.0.0 – 172.31.255.255 1,048,576 16 contiguous class Bs 172.16.0.0/12 (255.240.0.0) 20 bits
based on this:
http://en.wikipedia.org/wiki/Private_network#Private_IPv4_address_spaces

and set IPs for the proxmox nodes in this network as well - and then connect the nodes via a switch exclusively for this network.
so each node will have two NICs

i still do not understand how proxmox distributes IP in 10.0.0.0/8 network - could you tell me how this is done?

many thanks once again,


Nicolas