Definition
I have installed Proxmox 3.2 and i am trying to configure a virtual machine as a communication server that handles all traffic and forwards them to the nodes with private ip.
I configured server for NAT networking with two CentOS virtual machines which has exactly same configuration.
What I Do
Proxmox wiki has a very limited and basic nat networking documentation.
I found similar problems (this, this) on here and on proxmox forums. I tried to understand basics of linux nat networking so I complete this very understandable tutorial from beginning to end. I read this article for iptables nat rules
Problems
After installation and configuration when I ping from host to VM or from VM to host the output is:
root@testPrx:~# ping 10.0.4.2
PING 10.0.4.2 (10.0.4.2) 56(84) bytes of data.
From 10.0.4.1 icmp_seq=2 Destination Host Unreachable
When I try a telnet connection to communication server's public ip from a server in the same network which has internet connection and (192.168.0.3)
bash-4.1# telnet 192.168.0.2 2701
Trying 192.168.0.2...
telnet: connect to address 192.168.0.2: No route to host
When I try telnet connection to localhost, 192.168.0.2 results same:
root@testPrx:~# telnet localhost 2701
Trying 127.0.0.1...
telnet: Unable to connect to remote host: Connection refused
Question
What is my mistake?
Configurations
All host and virtual machines configurations are:
Proxmox Server
Proxmox version
root@testPrx:~# pveversion
pve-manager/3.2-4/e24a91c1 (running kernel: 2.6.32-29-pve)
Network interfaces
Network interfaces added by web interface:
- net0 -> vmbr0
net1 -> vmbr1
root@testPrx:~# cat /etc/network/interfacesauto lo iface lo inet loopback auto vmbr0 iface vmbr0 inet static address 192.168.0.2 netmask 255.255.255.0 gateway 192.168.0.1 bridge_ports eth0 bridge_stp off bridge_fd 0 auto vmbr1 iface vmbr1 inet static address 10.0.4.1 netmask 255.255.255.0 bridge_ports none bridge_stp off bridge_fd 0 post-up echo 1 > /proc/sys/net/ipv4/ip_forward post-up iptables -t nat -A POSTROUTING -s '10.0.4.0/24' -o vmbr0 -j MASQUERADE post-down iptables -t nat -D POSTROUTING -s '10.0.4.0/24' -o vmbr0 -j MASQUERADE #these rules forward traffic on port 2701 to port 22 on the VM at IP 10.0.4.2 post-up iptables -t nat -A PREROUTING -i vmbr0 -p tcp --dport 2701 -j DNAT --to 10.0.4.2:22 post-down iptables -t nat -D PREROUTING -i vmbr0 -p tcp --dport 2702 -j DNAT --to 10.0.4.2:22
Firewall rules of nat ( there is no any filters)
root@testPrx:~# iptables -L -t nat
Chain PREROUTING (policy ACCEPT)
target prot opt source destination
DNAT tcp -- anywhere anywhere tcp dpt:2701 to:10.0.4.2:22
Chain POSTROUTING (policy ACCEPT)
target prot opt source destination
MASQUERADE all -- 10.0.4.0/24 anywhere
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
Routing table
root@testPrx:~# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
10.0.4.0 * 255.255.255.0 U 0 0 0 vmbr1
192.168.0.0 * 255.255.255.0 U 0 0 0 vmbr0
default 192.168.0.1 0.0.0.0 UG 0 0 0 vmbr0
Ip forwarding
root@testPrx:~# cat /proc/sys/net/ipv4/ip_forward
1
Virtual Machines
OS version
-bash-4.1# cat /etc/redhat-release
CentOS release 6.4 (Final)
Interfaces
eth0
-bash-4.1# cat /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
TYPE=Ethernet
ONBOOT=yes
NM_CONTROLLED=no
BOOTPROTO=none
IPADDR=192.168.0.3
GATEWAY=192.168.0.1
NETMASK=255.255.255.0
eth1
-bash-4.1# cat /etc/sysconfig/network-scripts/ifcfg-eth1
DEVICE=eth1
TYPE=Ethernet
ONBOOT=yes
NM_CONTROLLED=no
BOOTPROTO=none
IPADDR=10.0.4.2
GATEWAY=10.0.4.1
NETMASK=255.255.255.0
SSH daemon running and listening port(22) succesfully
-bash-4.1# netstat -puntl
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:85 0.0.0.0:* LISTEN 1100/sshd
Routing Table
-bash-4.1# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
10.0.4.0 * 255.255.255.0 U 0 0 0 eth1
192.168.0.0 * 255.255.255.0 U 0 0 0 eth0
link-local * 255.255.0.0 U 1002 0 0 eth0
link-local * 255.255.0.0 U 1003 0 0 eth1
default 10.0.4.1 0.0.0.0 UG 0 0 0 eth1
