gary_lucas (19) [Avatar] Offline
#1
on page 64
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NOTE
NAT Translation
So you want to be able to talk out? If you want to be able to
communicate outside your OpenStack network from your new VM,
you can translate request from your VM to an outside network using
the command shown below. After issuing this command, internet
communication such as: "ping 8.8.8.8" should work, assuming your
OpenStack node already has connectivity.
sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
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I think this is poorly described, are you talking about the instance, the host or etc?
echeadle (87) [Avatar] Offline
#2
Re: unclear instructions
To end the suspense, on the host you run:
sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

I assumed it was on the host, but in re-reading I can see how it might be confusing. After quickly re-reading part of the chapter, I don't know how I made the decision it was the host. But in an Note, the information should stand alone and so you point is valid. I would like to think I was smart and figured it out, but it could just as easily be I was lucky.
gary_lucas (19) [Avatar] Offline
#3
Re: unclear instructions
I kind of assumed it was on the host, but it's really not clear.

There are buried assumptions in the statement, if someone doesn't know what the command does (this book does describe it's for a broad audience) then it would be entirely unclear.

Also, it's assuming that eth0 is the correct interface. On my machines it could be anywhere between eth0 and eth3 any box with multiple NIC's (on top of any other crazy configs) run the possibility of confusion.

G
cody.bumgardner (57) [Avatar] Offline
#4
Re: unclear instructions
Thanks for the feedback. This needs to be made clear.

You want to run this command on the node that is running devstack. In most cases this will be a physical machine. There is no need to run this command on any VM that you create inside DevStack.

This is basically a hack to let people run devstack on a machine with one network adapter. As we go into Part II, the manual install, there will be more requirements and strange things like this will go away.

Thanks,
Cody