[neutron] Disable dhcp drop rule

Eugen Block eblock at nde.ag
Thu Aug 20 08:22:06 UTC 2020


just a quick follow-up on this: disabling port_security only on the  
specified port works as expected.
Although this is still not an optimal solution we can live with it for now.

Thanks again and best regards,

Zitat von Eugen Block <eblock at nde.ag>:

> That sounds promising, thank you! I had noticed that option but  
> didn’t have a chance to look closer into it.
> I’ll try that tomorrow.
> Thanks for the tip!
> Zitat von Ben Nemec <openstack at nemebean.com>:
>> On 8/19/20 8:36 AM, Eugen Block wrote:
>>> Hi *,
>>> we recently upgraded our Ocata Cloud to Train and also switched  
>>> from linuxbridge to openvswitch.
>>> One of our instances within the cloud works as DHCP server and to  
>>> make that work we had to comment the respective part in this file  
>>> on the compute node the instance was running on:
>>> /usr/lib/python2.7/site-packages/neutron/agent/linux/iptables_firewall.py
>>> Now we tried the same in
>>> /usr/lib/python3.6/site-packages/neutron/agent/linux/openvswitch_firewall/firewall.py  
>>> /usr/lib/python3.6/site-packages/neutron/agent/linux/iptables_firewall.py
>>> but restarting openstack-neutron-openvswitch-agent.service didn't  
>>> drop that rule, the DHCP reply didn't get through. To continue  
>>> with our work we just dropped it manually, so we get by, but since  
>>> there have been a couple of years between Ocata and Train, is  
>>> there any smoother or better way to achieve this? This seems to be  
>>> a reoccuring request but I couldn't find any updates on this  
>>> topic. Maybe someone here can shed some light? Is there more to  
>>> change than those two files I mentioned?
>> You might try disabling port-security on the instance's port.  
>> That's what we use in OVB to allow a DHCP server in an instance now.
>> neutron port-update [port-id] --port_security_enabled=False
>> That will drop all port security for that instance, not just the  
>> DHCP rule, but on the other hand it leaves the DHCP rule in place  
>> for any instances you don't want running DHCP servers.
>>> Any pointers are highly appreciated!
>>> Best regards,
>>> Eugen

More information about the openstack-discuss mailing list