SUSE Cloud/Docker

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Revision as of 15:37, 13 February 2017 by Bmwiedemann (Talk | contribs) (add vxlan)

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MTU problems

When deploying SUSE OpenStack Cloud with the default settings, you get openvswitch with gre tunnels. The gre (same with vxlan) headers eat away some byte of your maximum transfer unit (MTU), so VMs will then only be able to transmit 1450 byte at a time instead of 1500. This causes some issues with docker.

using docker in a cloud


edit /etc/sysconfig/docker and set



Use iptables to limit tcp sizes in the cloud instance VM - probably like this:

iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS  --clamp-mss-to-pmtu

or something like

iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss 1320

using docker-compose in a cloud