Assistance with setting up an LTSP (Edubunt) server in KVM

greavette

Renowned Member
Apr 13, 2012
163
9
83
Hello,

We use Proxmox 2.1. I have two network cards on my Host server, eth0 and eth1.

In networking on the Proxmox Gui I have assigned vmbr0 to eth0 setup with IP 192.168.4.5. My Gateway is 192.168.4.1
I can ping 192.168.4.5 and my Virtual guests can access the internet and other computers on my network.

Also in networking on the Proxmox Gui I have assigned vmbr1 to eth1 setup with IP 192.168.5.5. I have not assigned a gateway for this (If I try I get an error that vmbr0 already has a gateway).
I cannot ping 192.168.5.5.

What I want to have for my setup is to use vmbr0 (eth0) connected to my local network and vmbr1 (eth1) connected to a switch. This switch is used to connect my Thin Clients to the LTSP Server. My plan is to use clients connected to LTSP server to be able to rdesktop to computers in my network.

What have I done incorrectly to get the vmbr1 (eth1) setup for the way I need to use it.

Thank you.
 
Hello,

We use Proxmox 2.1. I have two network cards on my Host server, eth0 and eth1.

In networking on the Proxmox Gui I have assigned vmbr0 to eth0 setup with IP 192.168.4.5. My Gateway is 192.168.4.1
I can ping 192.168.4.5 and my Virtual guests can access the internet and other computers on my network.

Also in networking on the Proxmox Gui I have assigned vmbr1 to eth1 setup with IP 192.168.5.5. I have not assigned a gateway for this (If I try I get an error that vmbr0 already has a gateway).
I cannot ping 192.168.5.5.

What I want to have for my setup is to use vmbr0 (eth0) connected to my local network and vmbr1 (eth1) connected to a switch. This switch is used to connect my Thin Clients to the LTSP Server. My plan is to use clients connected to LTSP server to be able to rdesktop to computers in my network.

What have I done incorrectly to get the vmbr1 (eth1) setup for the way I need to use it.

Thank you.
Hi,
looks ok - from where do you want to ping 192.168.5.5? From the VMs, which are in the 192.168.4.0/24-range? In this case the traffic go to the default gateway (192.168.4.1) and this must find the route to 192.168.5.5... look with "tcpdump -i vmbr0 host 192.168.5.5" to find the issue.

If you tried to ping from 192.168.5.0/24 there must something wrong with the setup (switchport/cable, perhaps eth1 not up?).
Try th find the issue with "tcpdump -i vmbr1 host 192.168.5.5".
BTW. vmbr1 need only an IP if the guests from this network must reach the GUI of the pve-server and the route to 192.168.4.5 is not working (no routing between this networks). To access the VMs on vmbr1 you don't need an IP.

Udo
 
You don't have to assign IP or gatway or whatever to vmbr1, think of it like a simple "switch" where you "connect" eth1 of the GUEST (your edubuntu installation).
You have to create, from proxmox web interface, 2 networks in your kvm guest, one associated with vmbr0 and the other with vmbr1.
Then in edubuntu you will find an eth0 and eth1. Check /etc/udev/rules.d/70-persistent-net.rules and make sure that eth0 is the one that is "plugged" with vmbr0 and eth1 with vmbr1 (just to make things easier, because mixing 0 and 1 creates confusion).
Then remove the network manager package and assign statically networking in /etc/network/interfaces
You need something like that:
Code:
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
     address 192.168.4.10
     netmask 255.255.255.0
     broadcast 192.168.4.255
     network 192.168.4.0
     gateway 192.168.4.1
     # ubuntu 12.04 e resolver want DNS here
     dns-nameservers .8.8.8

auto eth1
iface eth1 inet static
     address 192.168.5.10
     netmask 255.255.255.0
     broadcast 192.168.5.255
     network 192.168.5.0

     # activate forward (you can also modify sysctl.conf instead)
     pre-up echo 1 > /proc/sys/net/ipv4/ip_forward
     # enable NAT
     pre-up iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
     down   iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE

you have to set dhcp on the "client" side inside KVM guest and so on, of course.
Rebooting you should be able to ping from 192.168.5.x network to 192.168.4.x one
 
I am having the same issue, I have done as suggested above and though the thin clients boot, I have no access to the internet and/or the gateway.
Any suggestions would be extrememly welcome.
 
Impossible. If you use thin clients, then you are running programs inside the server so you don't need nat and forwarding, and you are ok.
If you use FAT clients, then your default gw, the one provided by dhcp, must be of course 192.168.5.10, i.e. the interface of the LTSP server that is on the same lan subnet of the clients, and that will forward the traffic and nat it with the options and iptable rule listed in my previous comment for the server nic setup.
In short in your fat client you will have something like:
ip: 192.168.5.101
default gw: 192.168.5.10
dns: whatever works for you

So inside your fat client try to ping 192.168.5.10, that must work.
Then try to ping 192.168.4.10, if does not work it means that the traffic is not natted and forwarded, or your default gw (of the client) is not set correctly, fix it
Then try to ping a public IP like ping 8.8.8.8, must work too
Finally, try to ping a hostname like ping www.google.com (or a host you are sure replies to ping, not all do). If it can't resolve the name this means that client dns setup is wrong, check and fix.
if you in lts.conf have a line with:
LDM_DEBUG_TERMINAL=True
once you are logged in the FAT client a terminal will open with (local) root privileges, so you can issue ifconfig / route / etc. commands to check the situation
All this stuff is basic networking, nothing directly related with proxmox.
 
Impossible. If you use thin clients, then you are running programs inside the server so you don't need nat and forwarding, and you are ok.
If you use FAT clients, then your default gw, the one provided by dhcp, must be of course 192.168.5.10, i.e. the interface of the LTSP server that is on the same lan subnet of the clients, and that will forward the traffic and nat it with the options and iptable rule listed in my previous comment for the server nic setup.
In short in your fat client you will have something like:
ip: 192.168.5.101
default gw: 192.168.5.10
dns: whatever works for you

So inside your fat client try to ping 192.168.5.10, that must work.
Then try to ping 192.168.4.10, if does not work it means that the traffic is not natted and forwarded, or your default gw (of the client) is not set correctly, fix it
Then try to ping a public IP like ping 8.8.8.8, must work too
Finally, try to ping a hostname like ping www.google.com (or a host you are sure replies to ping, not all do). If it can't resolve the name this means that client dns setup is wrong, check and fix.
if you in lts.conf have a line with:
LDM_DEBUG_TERMINAL=True
once you are logged in the FAT client a terminal will open with (local) root privileges, so you can issue ifconfig / route / etc. commands to check the situation
All this stuff is basic networking, nothing directly related with proxmox.

Hi,

The reason for packet forwarding is to improve the performance of web based mulit media, rather than using fat clients, you can use something called local-apps. This means that all internet traffic is sent to the clients rather than been processed on the server, thereby giving a huge performance boost to youtube etc.
Thanks for the suggestions though, I will be pleased to try them out.
 

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