openstack team mailing list archive

[Jimmy Tsai <cmingt@xxxxxxxxx>]

Thanks Vish & Mike.

It works very well after flush the anti-spoofing rules , I  change the IP
address and bind alias IP to an interface,
but when I restart nova-network and nova-compute , I can't ping neither the
IP I changed nor the instances I haven't changed.
I'll try to figure out what happened with that !!

Even I change the IP address, I can't not see the correct address on
Dashboard, because the record of nova.fixed_ips not changed.
I should try with FlatManager to allocate static IP.

Thanks,
-Jimmy

2012/4/27 Mike Scherbakov <mihgen@xxxxxxxxx>

>
>
> On Thu, Apr 26, 2012 at 10:31 PM, Vishvananda Ishaya <
> vishvananda@xxxxxxxxx> wrote:
>
>>
>> On Apr 25, 2012, at 7:31 PM, Jimmy Tsai wrote:
>>
>> >
>> > Hi everyone,
>> >
>> > I'm running with Essex 2012.1,
>> > and have some questions about the nova network operation,
>> >
>> > 1. Is it possible manually assigned IP address to a launched instance,
>> my situation is :
>> > after instance boot up (OS: CentOS 6.2), I changed the
>> /etc/sysconfig/network-scripts/ifcfg-eth0 setting
>> > from dhcp to static (the same subnet as created by command :
>> nova-manage create network....), and restart the network service,
>> > And then I couldn't ssh or ping the instance from other server with the
>> same subnet.
>> > What is the problem ?  I checked the iptables policies on the compute
>> host, and find nothing about the DROP packets.
>> > I also tried to changed the record from nova.fixed_ips table and
>> libvirt.xml of the instance, then reboot the instance, still not worked.
>> > I used FlatDHCP  as my network manager.
>>
>> You can't do this.  Libvirt sets up no mac spoofing and no ip spoofing so
>> the ip address needs to match the dhcp'd one. You should be able to switch
>> to a static and use the same info that you get from dhcp though.
>> >
>> > 2. According to the first question, I have another requirement to set
>> up a loopback IP address (lo:0) on the running instance, after setting was
>> completed,I couldn't ping or ssh the loopback IP from the same subnet, and
>> I tried to set a alias IP address with eth0:0, but still not get worked.
>> > Any ideas with this ?
>>
>
>> Not sure
>>
> I guess it's the same issue as with setting a different IP from what
> dnsmasq provided. You can try ebtables -F; ebtables -t nat -F to flush
> those anti spoofing rules.
>

>> >
>> > 3. Is there any way to use 2 NICs with different subnets on instances?
>> I want to separate the network traffic.
>> > Now I'm running with one bridged interface (br100), and it works well.
>>  In order to backup the large log files,
>> > I'm planing to use 2 NICs for the compute hosts, I want use 2 vNICs on
>> instance, one for web service and the other for log backup,
>> > I think I should create a new network for the second bridged interface,
>> but I can't find any document to guild me.
>>
>> This is definitely possible with FlatManager (You could use cloud_config
>> drive and some version of contrib/openstack-config converted to work with
>> centos to set up the interfaces)
>>
>> It was possible at one point with FlatDHCPManager as well by creating
>> multiple networks and using a specific combination of config options like
>> use_single_default_gateway. I don' t know if anyone has tried this for a
>> while so there may be issues with it. You might try creating a second
>> network and setting use_single_default_gateway and see what happens.
>>
> Confirm that it works with Essex release.
> If you don't specify  use_single_default_gateway=true your default route
> will be jumping from one interface to another. If you both subnets are
> covered by --fixed_network, it's fine even without setting
> the use_single_default_gateway.
>
>
>> There are plans underway to support this by only dhcping the first
>> interface and allowing a guest agent to set up the other interfaces, but it
>> isn't in place yet.
>>
>> Vish
>> _______________________________________________
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>>
>
>
>
> --
> Mike Scherbakov
>