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flannel-io / flannel

flannel is a network fabric for containers, designed for Kubernetes
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Investigate VXLAN offload support #366

Closed eyakubovich closed 1 year ago

eyakubovich commented 9 years ago

Some NICs support VXLAN offload (http://www.intel.com/content/dam/www/public/us/en/documents/technology-briefs/overlay-networks-using-converged-network-adapters-brief.pdf) but I don't know what needs to be done (if anything) to enable it with flannel.

jeremyeder commented 9 years ago

Nothing special. It gets enabled/disabled with 

# ethtool -k $NIC tx-udp_tnl-segmentation off

It's been enabled by default on all the NICs we've experimented with, including the Intel ones you linked to.

eyakubovich commented 9 years ago

@jeremyeder That's great news. I now wonder what happens if flannel is running inside a VM. How does VXLAN play with already virtualized NIC w.r.t. to offloads.

jeremyeder commented 8 years ago

If you terminate inside the guest, then no, you won't use the offload. virtio_net doesn't support VXLAN-offload. AFAICT vmxnet doesn't either. If you terminate on the host and send decap'd traffic into a guest, then you're OK.

A team mate of mine wrote a whitepaper detailing what OpenStack Neutron does with VXLAN-offloads: https://access.redhat.com/articles/1749113

philips commented 8 years ago

@jeremyeder Is this the same as this? https://github.com/coreos/flannel/pull/397

jeremyeder commented 8 years ago

@philips nope.

jeremyeder commented 8 years ago

We need NIC-agnostic vxlan offload...until then, 10G is a pipe-dream in the public cloud.

chinglinwen commented 4 years ago

@jeremyeder I'm using ethtool -K flannel.1 tx off to disable offloading, somehow it got re-enabled (maybe because of flannel restart? )

What can I do ?

# check
ethtool -k flannel.1 | grep tx-checksumming
# disable it
ethtool -K flannel.1 tx off
stale[bot] commented 1 year ago

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.