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Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Shuah Khan , linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next 0/3] net: nexthop: per-nexthop UDP dst port for fdb (VXLAN) nexthops Message-ID: <20260713122339.GA548566@shredder> References: <20260712191218.236-1-jack4it@gmail.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260712191218.236-1-jack4it@gmail.com> X-ClientProxiedBy: TL2P290CA0002.ISRP290.PROD.OUTLOOK.COM (2603:1096:950:2::12) To SA3PR12MB7901.namprd12.prod.outlook.com (2603:10b6:806:306::12) Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SA3PR12MB7901:EE_|CY8PR12MB7172:EE_ X-MS-Office365-Filtering-Correlation-Id: cde293c8-49e8-49a4-a4ea-08dee0d996e7 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|23010399003|7416014|366016|1800799024|22082099003|18002099003|56012099006|11063799006; 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Each leg carries its own remote IP, but the UDP > destination port is always taken from the VXLAN device (vxlan->cfg.dst_port) > and cannot be set per leg. > > Some deployments pack several receivers behind a single underlay IP and tell > them apart by UDP destination port. To spread flows across such receivers they I don't understand the "tell them apart" phrasing. Aren't all of these receivers interchangeable given you are load balancing between them? > need a nexthop group whose legs share the remote IP but differ in UDP port, > which is not currently expressible. I think you will need to provide more details about the use case given you are asking us to accept new uAPI which we will need to maintain forever. The FDB nexthop groups make sense when you want to spread overlay traffic between several distinct VTEPs. In the EVPN-MH use case these VTEPs are different TOR switches. In your use case, why can't the load balancing happen at the target host (e.g., using XDP / TC / SO_REUSEPORT / flow classification)? To be clear, I'm not strictly against the idea (we can talk about the implementation later), but I would like to understand why your use case can't be addressed using existing mechanisms (or why it's undesirable). Thanks