Instance Internet connection problems
Hi,
I have a 3 node setup with vagrant + VirtualBox which is similar to the official OpenStack Manuals. To give my instances access to the internet I added another bridged interface to my Network Node and an SANT rule. My network node is at 192.168.10.201 and my instances receive floating IPs from 192.168.10.10 to 20. I set the gateway of the external subnet to 192.168.10.201. So the traffic from the instances is received at the network node and from there to my labs LAN. The above mentioned SNAT rule is
iptables -t nat -A POSTROUTING -s 192.168.10.0/24 -j SNAT --to-source <IP from bridge to lab LAN>
Now my problems start. From the instances I ruled out the usual GRE issues and set the MTU down. I can now ping hostnames successfully. But if I try to wget a file it takes ~30 secs to start the download and then is extremely slow. I can't figure out why it takes so long for the transfer to start. I would love some suggestions or maybe other ways to give my instances a proper internet connection. How did you make it in your testlab?
Thanks
Hi, in my experience standard configuration for external subnet should set the gateway as your real gateway. Then you do not need any additional SNAT rule on your network node.
Have you tried that configuration and switched to the actual one for any reason?
Would this changes to iptables help
$ iptables -A FORWARD -d 192.168.10.0/24 -j ACCEPT
$ iptables -A FORWARD -s 192.168.10.0/24 -j ACCEPT
$ iptables -t nat -I POSTROUTING 1 -s 192.168.10.0/24 -o eth0 -j MASQUERADE
Antonio - Tried that, no internet than.
@dbaxps - Switching to these rules made the problem not better or worse.
I would try
$ tcpdump -vv -i eth0 ( on Neutron Server Node)
when VM does slow networking. I guess somewhere incorrect checksums should be captured
You better know your gateways and bridges to verify for bad checksums. Then disable checksums offloading on this interface.
On Compute Node when instance is running
brctl showshould report you qbr-xxxxxxxx bridge.First thing to verify is the vm's bridge. For instance:
$ brctl show
bridge name bridge id STP enabled interfaces
qbr1492886c-c7 8000.46de29f7bcc9 no qvb1492886c-c7
qbr6cc9af1a-5f 8000.aa387a60beaa no qvb6cc9af1a-5f
qbrd18de1da-fd 8000.3a26a24a7968 no qvbd18de1da-fd
qbrfb873e61-0a 8000.b2fb77d43bd6 no qvbfb873e61-0a
tapfb873e61-0a
$tcpdump -vv -i qbrfb873e61-0a