From 33a1aaf82bcf41a9d23539f859c83daa385beca5 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Fri, 25 Sep 2020 17:56:49 -0700 Subject: [PATCH] docs: vxlan: add info about device features Add some information about VxLAN-related netdev features and how to dump port table via ethtool. Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller --- Documentation/networking/vxlan.rst | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/Documentation/networking/vxlan.rst b/Documentation/networking/vxlan.rst index ce239fa01848..2759dc1cc525 100644 --- a/Documentation/networking/vxlan.rst +++ b/Documentation/networking/vxlan.rst @@ -58,3 +58,31 @@ forwarding table using the new bridge command. 3. Show forwarding table:: # bridge fdb show dev vxlan0 + +The following NIC features may indicate support for UDP tunnel-related +offloads (most commonly VXLAN features, but support for a particular +encapsulation protocol is NIC specific): + + - `tx-udp_tnl-segmentation` + - `tx-udp_tnl-csum-segmentation` + ability to perform TCP segmentation offload of UDP encapsulated frames + + - `rx-udp_tunnel-port-offload` + receive side parsing of UDP encapsulated frames which allows NICs to + perform protocol-aware offloads, like checksum validation offload of + inner frames (only needed by NICs without protocol-agnostic offloads) + +For devices supporting `rx-udp_tunnel-port-offload` the list of currently +offloaded ports can be interrogated with `ethtool`:: + + $ ethtool --show-tunnels eth0 + Tunnel information for eth0: + UDP port table 0: + Size: 4 + Types: vxlan + No entries + UDP port table 1: + Size: 4 + Types: geneve, vxlan-gpe + Entries (1): + port 1230, vxlan-gpe