I understand. This has been discussed previously on the mailing list. You are welcome to submit a patch upstream to provide that capability, but I suspect you will get some resistance--especially from the Linux kernel community.
--Justin > On Aug 27, 2019, at 11:25 PM, bindiya Kurle <[email protected]> wrote: > > Hi Justin, > > Thanks for the clarification. I agree to your point ,but consider a use-case > if I have routing decision only based on destination ip then as per current > implementation, ovs will add 2 flows (in data path)for packets coming from > different source and if the TTL happens to be different for them .This will > reduce number of flows that can be supported with ovs. If decrement TTL was > done in kernel ,it would have ended in adding one flow only. > > Regards, > Bindiya > > Regards, > Bindiya > > On Tue, Aug 27, 2019 at 9:48 PM Justin Pettit <[email protected]> wrote: > I think it was considered cleaner from an ABI perspective, since it doesn't > require another action, since "set" was already supported. In practice, I > don't think it's a problem, since usually a TTL decrement is associated with > a routing decision, and TTLs tend to be fairly static between two hosts. > > --Justin > > > > On Aug 27, 2019, at 1:11 AM, bindiya Kurle <[email protected]> wrote: > > > > hi , > > I have a question related to dec_ttl action implemented in datapath. > > when dec_ttl action is configured in OVS following action get added in > > datapath. > > > > recirc_id(0),in_port(2),eth(),eth_type(0x0800),ipv4(ttl=64,frag=no), > > packets:3, bytes:294, used:0.068s, actions:set(ipv4(ttl=63)),3, > > > > if packet comes with different TTL on same port then one more action get > > added in datapath. > > for ex: > > recirc_id(0),in_port(2),eth(),eth_type(0x0800),ipv4(ttl=9,frag=no), > > packets:3, bytes:294, used:0.068s, actions:set(ipv4(ttl=8)),3, > > > > Could someone please explain why dec_ttl is implemeted as a set action > > rather than dec_ttl action. > > > > > > I mean , why for different ttl one more rule get added rather than just > > adding it as following as done in userspace > > > > recirc_id(0),in_port(3),eth(),eth_type(0x0800),ipv4(frag=no), packets:3, > > bytes:294, used:0.737s, actions:dec_ttl,2 > > > > Regards, > > Bindiya > > _______________________________________________ > > discuss mailing list > > [email protected] > > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss > _______________________________________________ discuss mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
