reduce ipip tunnel MTU 20 to accommodate the tunnel overhead

Murali Reddy · Murali Reddy · commit 898d78d68864 · 2017-08-07T19:35:36.000+05:30
Fixes #108
diff --git a/app/controllers/network_routes_controller.go b/app/controllers/network_routes_controller.go
@@ -390,6 +390,10 @@ func (nrc *NetworkRoutingController) injectRoute(path *table.Path) error {
 			if err := netlink.LinkSetUp(link); err != nil {
 				return errors.New("Failed to bring tunnel interface " + tunnelName + " up due to: " + err.Error())
 			}
+			// reduce the MTU by 20 bytes to accommodate ipip tunnel overhead
+			if err := netlink.LinkSetMTU(link, link.Attrs().MTU-20); err != nil {
+				return errors.New("Failed to set MTU of tunnel interface " + tunnelName + " up due to: " + err.Error())
+			}
 		} else {
 			glog.Infof("Tunnel interface: " + tunnelName + " for the node " + nexthop.String() + " already exists.")
 		}

Original file line number	Diff line number	Diff line change
`@@ -390,6 +390,10 @@ func (nrc NetworkRoutingController) injectRoute(path table.Path) error {`
`390`	`390`	`if err := netlink.LinkSetUp(link); err != nil {`
`391`	`391`	`return errors.New("Failed to bring tunnel interface " + tunnelName + " up due to: " + err.Error())`
`392`	`392`	`}`
	`393`	`+ // reduce the MTU by 20 bytes to accommodate ipip tunnel overhead`
	`394`	`+ if err := netlink.LinkSetMTU(link, link.Attrs().MTU-20); err != nil {`
	`395`	`+ return errors.New("Failed to set MTU of tunnel interface " + tunnelName + " up due to: " + err.Error())`
	`396`	`+ }`
`393`	`397`	`} else {`
`394`	`398`	`glog.Infof("Tunnel interface: " + tunnelName + " for the node " + nexthop.String() + " already exists.")`
`395`	`399`	`}`