diff options
| author | Ben Pfaff <blp@nicira.com> | 2011-02-01 11:32:06 -0800 |
|---|---|---|
| committer | Ben Pfaff <blp@nicira.com> | 2011-02-04 09:46:26 -0800 |
| commit | f915f1a8ca180828983ef22cf2fd21b8f010b972 (patch) | |
| tree | cd34e78f86df1bdadc7430da75beb75403c27619 /include | |
| parent | bfa68a2b1fc49a8755748548836e92a5bae7bcb3 (diff) | |
| download | openvswitch-f915f1a8ca180828983ef22cf2fd21b8f010b972.tar.gz | |
datapath: Consider tunnels to have no MTU, fixing jumbo frame support.
Until now, tunnel vports have had a specific MTU, in the same way that
ordinary network devices have an MTU, but treating them this way does not
always make sense. For example, consider a datapath that has three ports:
the local port, a GRE tunnel to another host, and a physical port. If
the physical port is configured with a jumbo MTU, it should be possible to
send jumbo packets across the tunnel: the tunnel can do fragmentation or
the physical port traversed by the tunnel might have a jumbo MTU.
However, until now, tunnels always had a 1500-byte MTU by default. It
could be adjusted using ODP_VPORT_MTU_SET, but nothing actually did this.
One alternative would be to make ovs-vswitchd able to set the vport's MTU.
This commit, however, takes a different approach, of dropping the concept
of MTU entirely for tunnel vports. This also solves the problem described
above, without making any additional work for anyone.
I tested that, without this change, I could not send 1600-byte "pings"
between two machines whose NICs had 2000-byte MTUs that were connected to
vswitches that were in turn connected over GRE tunnels with the default
1500-byte MTU. With this change, it worked OK, regardless of the MTU of
the network traversed by the GRE tunnel.
This patch also makes "patch" ports MTU-less.
It might make sense to remove vport_set_mtu() and the associated callback
now, since ordinary network devices are the only vports that support it
now.
Signed-off-by: Ben Pfaff <blp@nicira.com>
Suggested-by: Jesse Gross <jesse@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>
Bug #3728.
Diffstat (limited to 'include')
| -rw-r--r-- | include/openvswitch/datapath-protocol.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/openvswitch/datapath-protocol.h b/include/openvswitch/datapath-protocol.h index 8645096ab..eafc80032 100644 --- a/include/openvswitch/datapath-protocol.h +++ b/include/openvswitch/datapath-protocol.h @@ -237,7 +237,8 @@ enum odp_vport_cmd { * @ODP_VPORT_ATTR_STATS: A &struct rtnl_link_stats64 giving statistics for * packets sent or received through the vport. * @ODP_VPORT_ATTR_ADDRESS: A 6-byte Ethernet address for the vport. - * @ODP_VPORT_ATTR_MTU: MTU for the vport. + * @ODP_VPORT_ATTR_MTU: MTU for the vport. Omitted if the vport does not have + * an MTU as, e.g., some tunnels do not. * @ODP_VPORT_ATTR_IFINDEX: ifindex of the underlying network device, if any. * @ODP_VPORT_ATTR_IFLINK: ifindex of the device on which packets are sent (for * tunnels), if any. |