1

I have installed a centos 6.5.

I have installed a host hypervisor, libvirt (kvm-qemu) managed with virt-manager I have installed two VMs (with kvm), centos 6.5 each one, too. e.g. centos65_1 and centos65_2 respectively.

The first one centos65_1 uses the default virtual network (NAT)

name: default
device: virbr0
state: active
autoboot: yes

ipv4 configuration
net: 192.168.122.0/24
dhcp:
start: 192.168.122.2
end: 192.168.122.254
forward: NAT

The second one centos65_2 uses a another one virtual network that I have created (a routed network)

name: routed_network
device: virbr1
state: active
autoboot: yes

ipv4 configuration
net: 192.168.100.0/24
dhcp:
start: 192.168.100.128
end: 192.168.100.254
forward: Routed

HOST:

ifconfig when both vms are running

[root@isis jvr]# ifconfig
Auto_eth0 Link encap:Ethernet  HWaddr 20:CF:30:AE:65:47  
          inet addr:192.168.1.15  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::22cf:30ff:feae:6547/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:35 errors:0 dropped:0 overruns:0 frame:0
          TX packets:35 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:19218 (18.7 KiB)  TX bytes:2888 (2.8 KiB)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:4958 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4958 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:1546831 (1.4 MiB)  TX bytes:1546831 (1.4 MiB)

virbr0    Link encap:Ethernet  HWaddr 52:54:00:96:45:DE  
          inet addr:192.168.122.1  Bcast:192.168.122.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:31 errors:0 dropped:0 overruns:0 frame:0
          TX packets:16 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:1886 (1.8 KiB)  TX bytes:1344 (1.3 KiB)

virbr1    Link encap:Ethernet  HWaddr 52:54:00:2C:02:F9  
          inet addr:192.168.100.1  Bcast:192.168.100.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:29 errors:0 dropped:0 overruns:0 frame:0
          TX packets:14 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:1774 (1.7 KiB)  TX bytes:1204 (1.1 KiB)

vnet0     Link encap:Ethernet  HWaddr FE:54:00:77:ED:C8  
          inet6 addr: fe80::fc54:ff:fe77:edc8/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:31 errors:0 dropped:0 overruns:0 frame:0
          TX packets:194 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:500 
          RX bytes:2320 (2.2 KiB)  TX bytes:10756 (10.5 KiB)

vnet1     Link encap:Ethernet  HWaddr FE:54:00:A2:8D:8B  
          inet6 addr: fe80::fc54:ff:fea2:8d8b/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:29 errors:0 dropped:0 overruns:0 frame:0
          TX packets:148 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:500 
          RX bytes:2180 (2.1 KiB)  TX bytes:8328 (8.1 KiB)




[root@isis jvr]# iptables -v -n -L --line-numbers
Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
num   pkts bytes target     prot opt in     out     source               destination         
1        0     0 ACCEPT     udp  --  virbr1 *       0.0.0.0/0            0.0.0.0/0           udp dpt:53 
2        0     0 ACCEPT     tcp  --  virbr1 *       0.0.0.0/0            0.0.0.0/0           tcp dpt:53 
3        0     0 ACCEPT     udp  --  virbr1 *       0.0.0.0/0            0.0.0.0/0           udp dpt:67 
4        0     0 ACCEPT     tcp  --  virbr1 *       0.0.0.0/0            0.0.0.0/0           tcp dpt:67 
5        0     0 ACCEPT     udp  --  virbr0 *       0.0.0.0/0            0.0.0.0/0           udp dpt:53 
6        0     0 ACCEPT     tcp  --  virbr0 *       0.0.0.0/0            0.0.0.0/0           tcp dpt:53 
7        0     0 ACCEPT     udp  --  virbr0 *       0.0.0.0/0            0.0.0.0/0           udp dpt:67 
8        0     0 ACCEPT     tcp  --  virbr0 *       0.0.0.0/0            0.0.0.0/0           tcp dpt:67 
9     4997 1566K ACCEPT     all  --  *      *       0.0.0.0/0            0.0.0.0/0           state RELATED,ESTABLISHED 
10       4   336 ACCEPT     icmp --  *      *       0.0.0.0/0            0.0.0.0/0           
11       4   240 ACCEPT     all  --  lo     *       0.0.0.0/0            0.0.0.0/0           
12       0     0 ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           state NEW tcp dpt:22 
13       0     0 ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           state NEW tcp dpt:5900 
14       0     0 ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           state NEW tcp dpt:5903 
15      10   572 REJECT     all  --  *      *       0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited 

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
num   pkts bytes target     prot opt in     out     source               destination         
1        6   504 ACCEPT     all  --  *      virbr1  0.0.0.0/0            192.168.100.0/24    
2        6   504 ACCEPT     all  --  virbr1 *       192.168.100.0/24     0.0.0.0/0           
3        0     0 ACCEPT     all  --  virbr1 virbr1  0.0.0.0/0            0.0.0.0/0           
4        0     0 REJECT     all  --  *      virbr1  0.0.0.0/0            0.0.0.0/0           reject-with icmp-port-unreachable 
5        0     0 REJECT     all  --  virbr1 *       0.0.0.0/0            0.0.0.0/0           reject-with icmp-port-unreachable 
6        0     0 ACCEPT     all  --  *      virbr0  0.0.0.0/0            192.168.122.0/24    state RELATED,ESTABLISHED 
7        0     0 ACCEPT     all  --  virbr0 *       192.168.122.0/24     0.0.0.0/0           
8        0     0 ACCEPT     all  --  virbr0 virbr0  0.0.0.0/0            0.0.0.0/0           
9        0     0 REJECT     all  --  *      virbr0  0.0.0.0/0            0.0.0.0/0           reject-with icmp-port-unreachable 
10       0     0 REJECT     all  --  virbr0 *       0.0.0.0/0            0.0.0.0/0           reject-with icmp-port-unreachable 
11       0     0 REJECT     all  --  *      *       0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited 

Chain OUTPUT (policy ACCEPT 5015 packets, 1551K bytes)
num   pkts bytes target     prot opt in     out     source               destination

[root@isis jvr]# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.100.0   *               255.255.255.0   U     0      0        0 virbr1
192.168.1.0     *               255.255.255.0   U     1      0        0 Auto_eth0
192.168.122.0   *               255.255.255.0   U     0      0        0 virbr0
default         192.168.1.1     0.0.0.0         UG    0      0        0 Auto_eth0


[root@isis jvr]# brctl show
bridge name bridge id       STP enabled interfaces
virbr0      8000.5254009645de   yes     virbr0-nic
                            vnet0
virbr1      8000.5254002c02f9   yes     virbr1-nic
                            vnet1

ping to clients(vms) is working.

CLIENTS(VMs)

centos65_1

it has static ip

nano /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE=eth0
TYPE=Ethernet
UUID=2b991cfa-4c3f-4619-8073-806710299fef
ONBOOT=yes
NM_CONTROLLED=yes
BOOTPROTO=none
IPADDR=192.168.122.5
PREFIX=24
GATEWAY=192.168.122.1
DNS1=192.168.122.1
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
NAME="System eth0"
HWADDR=52:54:00:77:ed:c8
NETMASK=255.255.255.0
USERCTL=no

At centos65_1 ping to the second vm 192.168.100.130, and to 192.168.1.15 and to 192.168.122.1 works. ping to 192.168.1.1 is working ping to google.com it works

NAT mode works.


centos65_2

it has static ip

nano /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE=eth0
HWADDR=52:54:00:a2:8d:8b
TYPE=Ethernet
UUID=d61375fb-6e4f-4f43-8015-9f7a218e1b39
ONBOOT=yes
NM_CONTROLLED=yes
BOOTPROTO=none
DNS1=192.168.100.1
IPV6INIT=no
USERCTL=no
IPADDR=192.168.100.130
NETMASK=255.255.255.0
GATEWAY=192.168.100.1

At centos65_2 ping to the second vm 192.168.122.5, and to 192.168.1.15 and to 192.168.100.1 works.

ping to 192.168.1.1 is not working ping to google.com is not working Routed Mode is not working

How is it possible I can't go to outside world?

The idea is made the centos host where virt-manager is installed a router+firewall for vms. I thought the new virtual network (routed_network) had made all network stuff.

What I need to do, to routed network works properly? I'm newbie in virtual networking.

I won't use DMZ at my local network, I would like the same network configuration at my local network and the server.

Thank you. Regards.

0

Is IP forwarding enabled? Check sysctl net.ipv4.ip_forward. If not, then enable it with sysctl -w net.ipv4.ip_forward=1 (to make that change permanent, add net.ipv4.ip_forward = 1 to /etc/sysctl.conf.

2
  • Yes, it is enabled. I have forgotten to write it. – Jvrq May 21 '14 at 22:59
  • I have added a route. 192.168.100.0/24 via 192.168.1.15 at /etc/sysconfig/network-scripts/route-xxx – Jvrq May 22 '14 at 15:34

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