[lxc-users] Internet to a container with local/private IP ( NAT ? )

Vijay Viswanathan vijay.vishy at gmail.com
Thu Jun 26 17:35:19 UTC 2014


I cannot pickup IP from 10.4.38.0/23 network for the containers.
I thought I picked up IP from 192.168.10.0/24. Isnt 192.168.10.2 from there ?
I know that some IP Masquerade/NAT setting is missing but dont know how to.

All I need is:
IN:
route/foward packets of 192.168.10.0/24 network that are received on eth1 to br0
[ also,
here I will need to forward port 22 traffic to lxc2/veth2
foward port 80 traffic to lxc3/veth3
]

OUT:
route/forward packets from br0 that are not 192.168.10.0/24 through
eth1 and put a br0 IP label on it

typical NAT with a help of some bridge and ip_forward ?



tried :

# brctl show
bridge name     bridge id               STP enabled     interfaces
br0             8000.fe264e1e9658       no              veth2
                                                        veth3
# brctl addif br0 eth1
# brctl show
bridge name     bridge id               STP enabled     interfaces
br0             8000.0000deadbeee       no              eth1
                                                        veth2
                                                        veth3


Thx.


On Thu, Jun 26, 2014 at 10:11 AM, Tamas Papp <tompos at martos.bme.hu> wrote:
>
> On 06/26/2014 07:00 PM, Vijay Viswanathan wrote:
>>
>> Hi
>> My interface looks like :
>>   br0[192.168.10.1] <-> veth2 [192.168.10.2]
>>   br0 <-> veth3 [192.168.10.3]
>> &
>>   an interface eth1 [ 10.4.38.222 ]
>> all three [br0, veth2, veth3 ] are in the same network [ 192.168.10. ]
>> so they are able to ping one another ( I set up the route for it )
>>
>> Now how do I ping-in/ping-out/connect to the container from my next
>> machine [10.4.38.221] that is in the 10.4.3x network ?
>>
>> ip_forward has 1 in it.
>>
>> IP forwarding should help here but it doesnt seem to be.
>> my iptables has nothing in it . I tried to iptables (  iptables -t nat
>> -A POSTROUTING -s 192.168.10.0/24 -o eth1 -j MASQUERADE ) with no
>> effect
>>
>>
>> ---------
>>
>> # ifconfig from host:
>> br0       Link encap:Ethernet  HWaddr FE:26:4E:1E:96:58
>>            inet addr:192.168.10.1  Bcast:192.168.10.255
>> Mask:255.255.255.0
>>            inet6 addr: fe80::6c17:ebff:fe0b:4960/64 Scope:Link
>>            UP BROADCAST RUNNING PROMISC MULTICAST  MTU:1500  Metric:1
>>            RX packets:935 errors:0 dropped:0 overruns:0 frame:0
>>            TX packets:463 errors:0 dropped:0 overruns:0 carrier:0
>>            collisions:0 txqueuelen:0
>>            RX bytes:66496 (64.9 KiB)  TX bytes:39538 (38.6 KiB)
>>
>> eth0      Link encap:Ethernet  HWaddr 00:00:DE:AD:BE:EF
>>            UP BROADCAST MULTICAST  MTU:1500  Metric:1
>>            RX packets:0 errors:0 dropped:0 overruns:0 frame:0
>>            TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
>>            collisions:0 txqueuelen:1000
>>            RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
>>
>> eth1      Link encap:Ethernet  HWaddr 00:00:DE:AD:BE:EE
>>            inet addr:10.4.38.182  Bcast:10.4.39.255  Mask:255.255.254.0
>>            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>>            RX packets:134332 errors:0 dropped:0 overruns:0 frame:0
>>            TX packets:1961 errors:0 dropped:0 overruns:0 carrier:0
>>            collisions:0 txqueuelen:1000
>>            RX bytes:19183426 (18.2 MiB)  TX bytes:169630 (165.6 KiB)
>>
>> eth1:0    Link encap:Ethernet  HWaddr 00:00:DE:AD:BE:EE
>>            inet addr:192.168.17.10  Bcast:192.168.17.255
>> Mask:255.255.255.0
>>            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>>
>> 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:12 errors:0 dropped:0 overruns:0 frame:0
>>            TX packets:12 errors:0 dropped:0 overruns:0 carrier:0
>>            collisions:0 txqueuelen:0
>>            RX bytes:756 (756.0 B)  TX bytes:756 (756.0 B)
>>
>> veth2     Link encap:Ethernet  HWaddr FE:E5:84:6E:5F:58
>>            inet6 addr: fe80::fce5:84ff:fe6e:5f58/64 Scope:Link
>>            UP BROADCAST RUNNING PROMISC MULTICAST  MTU:1500  Metric:1
>>            RX packets:475 errors:0 dropped:0 overruns:0 frame:0
>>            TX packets:896 errors:0 dropped:0 overruns:0 carrier:0
>>            collisions:0 txqueuelen:1000
>>            RX bytes:40254 (39.3 KiB)  TX bytes:59336 (57.9 KiB)
>>
>> veth3     Link encap:Ethernet  HWaddr FE:26:4E:1E:96:58
>>            inet6 addr: fe80::fc26:4eff:fe1e:9658/64 Scope:Link
>>            UP BROADCAST RUNNING PROMISC MULTICAST  MTU:1500  Metric:1
>>            RX packets:441 errors:0 dropped:0 overruns:0 frame:0
>>            TX packets:893 errors:0 dropped:0 overruns:0 carrier:0
>>            collisions:0 txqueuelen:1000
>>            RX bytes:37874 (36.9 KiB)  TX bytes:58770 (57.3 KiB)
>>
>> # route
>> Kernel IP routing table
>> Destination     Gateway         Genmask         Flags Metric Ref    Use
>> Iface
>> default         10.4.39.254     0.0.0.0         UG    0      0        0
>> eth1
>> 10.4.38.0       *               255.255.254.0   U     0      0        0
>> eth1
>> 192.168.10.0    *               255.255.255.0   U     0      0        0
>> br0
>> 192.168.17.0    *               255.255.255.0   U     0      0        0
>> eth1
>> # iptables --list
>> Chain INPUT (policy ACCEPT)
>> target     prot opt source               destination
>>
>> Chain FORWARD (policy ACCEPT)
>> target     prot opt source               destination
>>
>> Chain OUTPUT (policy ACCEPT)
>> target     prot opt source               destination
>> #
>
>
> If I were you, I would use bridged network setup and pick up IP for
> containers from the main network (10.4.38.0/23) since it's also a private
> network. If it's not possible for some reason, then you still can use IP
> from 192.168.10.0/24.
> It unnecessary to make it more complicated. Why would you do that?
>
> tamas
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> lxc-users at lists.linuxcontainers.org
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