On 03/17/2016 03:27 PM, Jesse Gross wrote: > On Thu, Mar 17, 2016 at 7:02 AM, Patrick Boutilier wrote: >> I have an IPIP tunnel setup between two hosts in different buildings. The >> Linux router they route through causes extreme slowness in the tunnel when >> running kernels from 3.18 on . tcpdump shows many cksum errors which don't >> show up in the 3.17 and earlier kernels. Speed goes back to normal when >> rx-checksumming and tx-checksumming are turned off using ethtool on the >> Linux router . Would this be an effect of bulk network packet transmission >> that was introduced in 3.18 or some other issue? > > I just sent out a likely fix, would you mind testing it? > https://patchwork.ozlabs.org/patch/599213/ > Yes, that patch fixes the problem. Thanks.