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multiple fixed-ip without filter

asked 2014-09-26 08:24:20 -0500

bernd gravatar image

Hi, I'm using icehouse with neutron and linux bridge, VLAN networks.

My goal is that an instance can bind secondary ip's dynamically. DHCP is using only an allocation pool segment of the subnet,leaving the rest for dynamic binding.

Currently I don't find any method to reach those dynamic ip's from outside. I've opened all communication via security rules - no effect. Seems like neutron is filtering letting only the assigned ip(s) in.

As a workaround if's used nova add-fixed-ip but this command doesn't allow to specify an ip and is using only ip's from the allocation-pool.

Is there a way to switch of the filter? Or any other method to accomplish this?

Thanks Bernd

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answered 2014-09-27 07:43:53 -0500

senyapsudah gravatar image

hi bernd, as as i know it is not possible. i have the same issue before then i change to flat network where no floating ip define but still the same issue. anyway, from there i can see that dhcp will only allocate one ip for the interface, then you need to manually force the instance to use the fix ip to you local can do it by telling your instance using below command:

ip addr add <ip>/<mask lenght=""> dev eth<number>

you can set it in your rc.local also which will survive reboot.

but take note that you will have to define the ip from the same port-id as it will use the same virtual mac address. if not, your instance will think it is a different interface causing it create another interface and this will not allow you to communicate to that interface event you have bind floating-ip to it.

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answered 2014-09-27 11:46:35 -0500

bernd gravatar image


thank's for the comment. I've tried this "local" binding. It works but only when the ip is also assigned to the port.

My problem is that, the application binds one or more application specific ip's dynamically. The nova add-fixed-ip cannot specify the ip. when adding an ip with nova add-fixed-ip and later an ip add add with this ip within the OS it works.

I would love to know how to switch this filtering off and let all ip's at least reach the OS NIC.

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answered 2014-09-28 19:41:20 -0500

scouw gravatar image

I think that you can add the secondary ip to allowed_address_pairs proprety of neutron port. I made this with pacemaker vip

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will the instance note about the second ip? or do we still need to manually configure it?

senyapsudah gravatar imagesenyapsudah ( 2014-09-28 23:34:45 -0500 )edit

You have to configure it manually.

scouw gravatar imagescouw ( 2014-09-29 03:49:21 -0500 )edit

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Asked: 2014-09-26 08:24:20 -0500

Seen: 207 times

Last updated: Sep 28 '14