Comments for Robotic Tendencies

Comment on Xen virtual interfaces with more than one IP by Robert McQueen

Robert McQueen — Mon, 09 Jun 2008 12:43:23 +0000

Russell: We’re using vif-route and network-route, meaning we don’t have any bridging set up on the dom0, it instead acts as a layer 3 router. Regardless of how the network is configured inside the domU, the configuration file needs to have a list of the IP addresses so that the vif-route script can add routes to those IPs in the dom0. We then use proxy_arp on the dom0’s eth0 so that people outside the machine can contact the VMs.

The reasons for us using this configuration are partly historical (bridging used to be unreliable in the past), but we keep it now as it allows a lot more “conventional” control of traffic and addressing using iptables and friends (rather than the slightly less conventional ebtables hidden features :D). We can list the addresses our customers are able to use in the configuration file, and enforcing it to prevent any spoofing is as simple as turning on rp_filter by default for all the interfaces on the machine.

Also, as a somewhat fringe benefit, it means the answer to “where is this VM running?” is findable using mtr. :D

Comment on Xen virtual interfaces with more than one IP by Russell Coker

Russell Coker — Mon, 09 Jun 2008 12:05:35 +0000

What’s the benefit of specifying an IP address in the Xen configuration?

I just specify the MAC address and then in the DomU use as many IP addresses as I want without any problems.

That said, thanks for the informative post. If you (or someone else) explains why I would want to put the IP addresses in the Xen configuration I’ll take advantage of this information to do what you have done.

Comment on Surströmming by Alban

Alban — Thu, 05 Jun 2008 22:47:25 +0000

I find this interesting, I would like to give it a try. But not for breakfast.

Comment on Surströmming by Jimmy

Jimmy — Thu, 05 Jun 2008 14:20:24 +0000

Lucky you! Surströmming is soooo delicious!
Hmm, I think we should have it this weekend. Our 2 year old son loves it!

Comment on Surströmming by spaetz

spaetz — Thu, 05 Jun 2008 13:46:29 +0000

I nearly wasn’t allowed on a flight because I had a tin of that in my luggage. They told me “if that thing explodes in the air we can discard the airplane”.

Be very scared indeed.

Comment on Fontconfig fun by robot101

robot101 — Thu, 05 Jun 2008 13:33:39 +0000

Fixed the link.

Comment on Surströmming by Janne

Janne — Thu, 05 Jun 2008 12:36:47 +0000

Wonderful! I live in Japan, and that’s one thing I miss here; you’re not allowed to bring it on airplanes so I just have to do without.

Flat bread, sliced boiled potatoes, some chopped onion and one herring. Roll up, eat, wash down with Hallands Fläder aquavit.

Comment on Surströmming by Karl Lattimer

Karl Lattimer — Thu, 05 Jun 2008 12:18:42 +0000

http://www.youtube.com/watch?v=vcnfEVqNdoA

does anyone want to eat that?

Comment on Surströmming by Mikael Hallenadl

Mikael Hallenadl — Thu, 05 Jun 2008 12:06:10 +0000

And managed to click submit too early. Was goint to say.

Enjoy!

(there are a lot of people who actually do like it).

Comment on Surströmming by Mikael Hallenadl

Mikael Hallenadl — Thu, 05 Jun 2008 12:02:46 +0000

You are right to be afraid. And be sure to be in a place where it’s actually possible to throw up. It’s not entirely uncommon that people do due to the combination of smell and taste :)