[Rdo-list] Outgoing traffic from instances! RDO icehouse with GRE fedora20

Rhys Oxenham roxenham at redhat.com
Mon Jul 7 09:30:03 UTC 2014

On 7 Jul 2014, at 06:24, Antonio C. Velez <acvelez at vidalinux.com> wrote:

> I'm using icehouse with GRE on fedora20 in two nodes 1 controller 1 compute, everything is working great, I can loging to ssh to the instances and ping to the internet ect. but when I try to install something with yum it says conection timeout, conecting to public servers using ramdon ports 443, 80, 22 doesn't work.

Check the MTU inside of the guest. If it’s at 1500, then it’s likely that you’ll experience significant packet fragmentation and severely degraded performance.

I usually force MTU to be 1400 inside of my guest, either by preconfiguring the image or by setting the MTU via the DHCP agent.

A manual configuration whilst the instance is running will confirm this. Try: ‘ip link set eth0 mtu 1400’


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