> Him Pim,
This was supposed to read "Hi Pim". Although I did to find a nice play on
"Hoi". ;-)
Ole
>
> I'm also doing a round now updating the Geneve implementation:
> - add direct {IPv4, IPv6} encapsulation support
> - validate protocol type (now all payload is blindly treated as Ethernet)
> - drop packets with C bit set
> - make well known port configurable
>
> cheers,
> Ole
>
>> On 14 Jan 2022, at 11:27, Pim van Pelt <[email protected]> wrote:
>>
>> Hoi,
>>
>> Neale, thank you for pointing that out! I verified the intent, and I can
>> confirm that VXLAN uses random source ports [1], and so does GENEVE [2], so
>> this is WAI. I mirrored traffic between the two VPP hosts, while running a
>> T-Rex bench.py with vm=var2 to scramble the src/dst IP addresses of the
>> inner payload. It resulted in the outer src_port scrambling, which is great.
>> So it seems I was reading the wrong part of the vxlan source code, and the
>> thing I wanted is already there. I'll update my article with this info, and
>> I'm only left wondering why there would be an option to set src_port when
>> creating a VXLAN tunnel (such an option is not present in GENEVE)?
>>
>> create vxlan tunnel src <local-vtep-addr> {dst <remote-vtep-addr>|group
>> <mcast-vtep-addr> <intf-name>} vni <nn> [instance <id>] [encap-vrf-id <nn>]
>> [decap-next [l2|node <name>]] [del] [l3] [src_port <local-vtep-udp-port>]
>> [dst_port <remote-vtep-udp-port>]
>> create geneve tunnel local <local-vtep-addr> {remote
>> <remote-vtep-addr>|group <mcast-vtep-addr> <intf-name>} vni <nn>
>> [encap-vrf-id <nn>] [decap-next [l2|node <name>]] [l3-mode] [del]
>>
>> groet,
>> Pim
>>
>> [1] (on the mirrored interface, watching traffic between rhino:Hu12/0/1 and
>> hippo:Hu12/0/1) tcpdump -ni enp5s0f3 port 4789
>> 11:19:54.887763 IP 10.0.0.1.4452 > 10.0.0.0.4789: VXLAN, flags [I] (0x08),
>> vni 8298
>> 11:19:54.888283 IP 10.0.0.1.42537 > 10.0.0.0.4789: VXLAN, flags [I] (0x08),
>> vni 8298
>> 11:19:54.888285 IP 10.0.0.0.17895 > 10.0.0.1.4789: VXLAN, flags [I] (0x08),
>> vni 8298
>> 11:19:54.899353 IP 10.0.0.1.40751 > 10.0.0.0.4789: VXLAN, flags [I] (0x08),
>> vni 8298
>> 11:19:54.899355 IP 10.0.0.0.35475 > 10.0.0.1.4789: VXLAN, flags [I] (0x08),
>> vni 8298
>> 11:19:54.904642 IP 10.0.0.0.60633 > 10.0.0.1.4789: VXLAN, flags [I] (0x08),
>> vni 8298
>> 11:19:54.908642 IP 10.0.0.1.54881 > 10.0.0.0.4789: VXLAN, flags [I] (0x08),
>> vni 8298
>> 11:19:54.910201 IP 10.0.0.1.11787 > 10.0.0.0.4789: VXLAN, flags [I] (0x08),
>> vni 8298
>> 11:19:54.910204 IP 10.0.0.0.13300 > 10.0.0.1.4789: VXLAN, flags [I] (0x08),
>> vni 8298
>> 11:19:54.919702 IP 10.0.0.1.55752 > 10.0.0.0.4789: VXLAN, flags [I] (0x08),
>> vni 8298
>> 11:19:54.919714 IP 10.0.0.0.22122 > 10.0.0.1.4789: VXLAN, flags [I] (0x08),
>> vni 8298
>> 11:19:54.944301 IP 10.0.0.0.42756 > 10.0.0.1.4789: VXLAN, flags [I] (0x08),
>> vni 8298
>> 11:19:54.944303 IP 10.0.0.1.8992 > 10.0.0.0.4789: VXLAN, flags [I] (0x08),
>> vni 8298
>> 11:19:54.954043 IP 10.0.0.1.49613 > 10.0.0.0.4789: VXLAN, flags [I] (0x08),
>> vni 8298
>> 11:19:54.954045 IP 10.0.0.0.16483 > 10.0.0.1.4789: VXLAN, flags [I] (0x08),
>> vni 8298
>> 11:19:54.954411 IP 10.0.0.0.37118 > 10.0.0.1.4789: VXLAN, flags [I] (0x08),
>> vni 8298
>> 11:19:54.954412 IP 10.0.0.1.26825 > 10.0.0.0.4789: VXLAN, flags [I] (0x08),
>> vni 8298
>> 11:19:54.959725 IP 10.0.0.1.5643 > 10.0.0.0.4789: VXLAN, flags [I] (0x08),
>> vni 8298
>>
>> [1] (on the mirrored interface, watching traffic between rhino:Hu12/0/1 and
>> hippo:Hu12/0/1) tcpdump -ni enp5s0f3 port 6081
>> 11:20:55.802406 IP 10.0.0.0.32299 > 10.0.0.1.6081: Geneve, Flags [none], vni
>> 0x206a: IP 16.0.0.45.1025 > 48.0.0.45.12: UDP, length 18
>> 11:20:55.802409 IP 10.0.0.1.44011 > 10.0.0.0.6081: Geneve, Flags [none], vni
>> 0x206a: IP 48.0.0.45.1025 > 16.0.0.45.12: UDP, length 18
>> 11:20:55.807711 IP 10.0.0.1.45503 > 10.0.0.0.6081: Geneve, Flags [none], vni
>> 0x206a: IP 48.0.0.47.1025 > 16.0.0.47.12: UDP, length 18
>> 11:20:55.807712 IP 10.0.0.0.45532 > 10.0.0.1.6081: Geneve, Flags [none], vni
>> 0x206a: IP 16.0.0.47.1025 > 48.0.0.47.12: UDP, length 18
>> 11:20:55.841494 IP 10.0.0.1.10795 > 10.0.0.0.6081: Geneve, Flags [none], vni
>> 0x206a: IP 48.0.0.50.1025 > 16.0.0.50.12: UDP, length 18
>> 11:20:55.841495 IP 10.0.0.0.61694 > 10.0.0.1.6081: Geneve, Flags [none], vni
>> 0x206a: IP 16.0.0.50.1025 > 48.0.0.50.12: UDP, length 18
>> 11:20:55.851719 IP 10.0.0.1.47581 > 10.0.0.0.6081: Geneve, Flags [none], vni
>> 0x206a: IP 48.0.0.48.1025 > 16.0.0.48.12: UDP, length 18
>> 11:20:55.851719 IP 10.0.0.0.52458 > 10.0.0.1.6081: Geneve, Flags [none], vni
>> 0x206a: IP 16.0.0.48.1025 > 48.0.0.48.12: UDP, length 18
>> 11:20:55.851772 IP 10.0.0.0.12360 > 10.0.0.1.6081: Geneve, Flags [none], vni
>> 0x206a: IP 16.0.0.52.1025 > 48.0.0.52.12: UDP, length 18
>> 11:20:55.855768 IP 10.0.0.1.39531 > 10.0.0.0.6081: Geneve, Flags [none], vni
>> 0x206a: IP 48.0.0.52.1025 > 16.0.0.52.12: UDP, length 18
>> 11:20:55.856296 IP 10.0.0.0.28635 > 10.0.0.1.6081: Geneve, Flags [none], vni
>> 0x206a: IP 16.0.0.51.1025 > 48.0.0.51.12: UDP, length 18
>>
>> On Fri, Jan 14, 2022 at 10:40 AM Neale Ranns <[email protected]> wrote:
>> Hi Pim,
>>
>>
>>
>> For VXLAN the intention is to use random source ports. The code you sight
>> builds the ‘static’ portion of the imposed header. The source ports are
>> overwritten with the hash of the encapped packet in encap.c:246
>>
>>
>>
>> /neale
>>
>>
>>
>>
>>
>> From: [email protected] <[email protected]> on behalf of Pim van Pelt
>> via lists.fd.io <[email protected]>
>> Date: Thursday, 13 January 2022 at 23:37
>> To: vpp-dev <[email protected]>
>> Subject: [vpp-dev] VXLAN and RSS
>>
>> Hoi folks,
>>
>>
>>
>> I did a deep dive today on VXLAN, GENEVE and compared it to GRE and L2XC -
>> the full read is here:
>>
>> https://ipng.ch/s/articles/2022/01/13/vpp-l2.html
>>
>>
>>
>> One thing that I observed is that both VXLAN and GENEVE use static source
>> ports. In the case of VLLs, (an l2 xconnect from a customer ethernet
>> interface into a tunnel), the customer port will be receiving IPv4 or IPv6
>> traffic (either tagged or untagged) and this allows the NIC to use RSS to
>> assign this inbound traffic to multiple queues, and thus multiple CPU
>> threads. That’s great, it means linear encapsulation performance.
>>
>> However,, once the traffic is encapsulated, it’ll become single flow with
>> respect to the remote host, ie we're sending from 10.0.0.0:4789 to the
>> remote 10.0.0.1:4789 and it is for this reason, that all decapsulation is
>> single threaded.
>>
>> One common approach is to use an ingress hash algorithm to choose from a
>> pool of source ports, or possibly a simpler round-robin over a pool of ports
>> 4000-5000, say, based on the inner payload. That way, the remote would be
>> able to use multiple RSS queues. However, VPP currently does not implement
>> that.
>>
>>
>>
>> I think the original author has this in mind as a future improvement based
>> on the comment on L295 in vxlan.c
>>
>> /* UDP header, randomize src port on something, maybe? */
>> udp->src_port = clib_host_to_net_u16 (t->src_port);
>> udp->dst_port = clib_host_to_net_u16 (t->dst_port);
>>
>>
>>
>> What would it take for src_port to not be static? It would greatly improve
>> VXLAN (and similarly, GENEVE) throughput on ingress.
>>
>>
>>
>> groet,
>>
>> Pim
>>
>> --
>>
>> Pim van Pelt <[email protected]>
>> PBVP1-RIPE - http://www.ipng.nl/
>>
>>
>>
>> --
>> Pim van Pelt <[email protected]>
>> PBVP1-RIPE - http://www.ipng.nl/
>>
>>
>
>
>
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