Him Pim,

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 <p...@ipng.nl> 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 <ne...@graphiant.com> 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: vpp-dev@lists.fd.io <vpp-dev@lists.fd.io> on behalf of Pim van Pelt via 
> lists.fd.io <pim=ipng...@lists.fd.io>
> Date: Thursday, 13 January 2022 at 23:37
> To: vpp-dev <vpp-dev@lists.fd.io>
> 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 <p...@ipng.nl> 
> PBVP1-RIPE - http://www.ipng.nl/
> 
> 
> 
> -- 
> Pim van Pelt <p...@ipng.nl> 
> PBVP1-RIPE - http://www.ipng.nl/
> 
> 

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