Re: [ovs-discuss] Query on DEC_ttl action implementation in datapath
Thanks. Is there any forum where i can discuss the design for same? Regards, Bindiya On Thu, Aug 29, 2019 at 1:22 AM Justin Pettit wrote: > 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 > 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 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 > 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 > > > disc...@openvswitch.org > > > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss > > > > ___ discuss mailing list disc...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
Re: [ovs-discuss] Query on DEC_ttl action implementation in datapath
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 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 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 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 > > disc...@openvswitch.org > > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss > ___ discuss mailing list disc...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
Re: [ovs-discuss] Query on DEC_ttl action implementation in datapath
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 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 > 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 > > disc...@openvswitch.org > > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss > > ___ discuss mailing list disc...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
Re: [ovs-discuss] Query on DEC_ttl action implementation in datapath
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 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 > disc...@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss ___ discuss mailing list disc...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
[ovs-discuss] Query on DEC_ttl action implementation in datapath
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 disc...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
