Description of problem: Currently the mtu is hardcoded to 1450. While this works for most cases, its not valid when the assumed underlay is an overlay itself. Also, if customer need to use jumbo frames it requires a global change. Reference: https://github.com/openshift/openshift-sdn/issues/120
Checked on puddle 2015.10.17-1 The MTU is configurable in node-config instead of hardcoding. For mtu 1450: # oc rsh hello-pod bash-4.3$ ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 14: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue link/ether 02:42:0a:01:00:04 brd ff:ff:ff:ff:ff:ff inet 10.1.0.4/24 scope global eth0 valid_lft forever preferred_lft forever inet6 fe80::42:aff:fe01:4/64 scope link valid_lft forever preferred_lft forever For mtu 1000: # oc rsh hello-pod bash-4.3$ ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 21: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1000 qdisc noqueue link/ether 02:42:0a:01:00:02 brd ff:ff:ff:ff:ff:ff inet 10.1.0.2/24 scope global eth0 valid_lft forever preferred_lft forever Verify the bug.
This fix is available in OpenShift Enterprise 3.1.