From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 2D8CB45B6A; Fri, 18 Oct 2024 18:43:53 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id A43494027C; Fri, 18 Oct 2024 18:43:52 +0200 (CEST) Received: from mail-pg1-f169.google.com (mail-pg1-f169.google.com [209.85.215.169]) by mails.dpdk.org (Postfix) with ESMTP id 4B05D40268 for ; Fri, 18 Oct 2024 18:43:51 +0200 (CEST) Received: by mail-pg1-f169.google.com with SMTP id 41be03b00d2f7-7e6ed072cdaso1653917a12.0 for ; Fri, 18 Oct 2024 09:43:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20230601.gappssmtp.com; s=20230601; t=1729269830; x=1729874630; darn=dpdk.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=tyhmJJGLJr8+/azLHsV3WbSa3Sf18OMICDVxiP4ZdCg=; b=il3V9eo/5BKOi6mC9iCWmpTLxArA+CCajxhzd+Dr/BQAoyvfh+Yrh8+ch72i1PAU8i 1lpg9pPhVb8VghW3j1XBKI6HnZG6KIR0Oew/nfcdoqSN9CfEBQDNyYywEL0iAsAw7DCQ xs2xxgGE49SC6cWGx+r/KmkPi0fSAT5GEQF8M8cqrk0OAE/bgYJIkQvu4pit/hryCVeD Uo/iiyyQR9A3CcZXhv63FwwDYRzp7kOFOyK1OaoVisvah38cVPvurMuhpPUmhBbAHygI UCDzF71EOkfKFoUH6Z9QMsy1U+STPeLji7+8wRD/hVl9Pp/wYGimzNNFYDPSVXCNlEzr hzMw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1729269830; x=1729874630; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=tyhmJJGLJr8+/azLHsV3WbSa3Sf18OMICDVxiP4ZdCg=; b=XWsxQuCCxorrtfhaYFZTLSS4EBeUrPQn47zXbYlJ1e2gTtnGcJgS8InS5e9/HXlCNz wOLMQIG2EmZExQkTox2bxhYwovipk9rDkceqZl/zInRmzgySkSIinuTFm/oscUY9RAI2 xfi1woK7maXtuW+Ffost4uZ6ahEOlO8ehag57YWUKD8uKGhMzFPubJ37FqzbWsthpsQF 2vXyrKJ1BrSzOksAzmSVvoFub+ELYK8Hfq3y/ctAzbqholpZaJ6CU3gkleF3SwB3imbt 9hJZkkAvmreKDe+oyia6JYNirMpXcoPB1hG+fXDR+uaaSFVSrtZHoKZEF8RLos+xME2m LI9Q== X-Gm-Message-State: AOJu0Yz5kpTwLpEc7LaajQ6y/lMz4+tjPlZF6lYemi5IDDExtszFdtJl fGEsVl/Dcc/4fh9AdHFskQir6CJ+r9Ia8NvypKcnEe/FX0K3rrmyluAaV0/8BFI= X-Google-Smtp-Source: AGHT+IHBpioL0j8gx19n3ljsBm6vIMIa0gWupfcXQBp578avVDwN5OTMBNCNknBmis28QrNP4M6zwQ== X-Received: by 2002:a05:6a20:e617:b0:1d9:2a55:a166 with SMTP id adf61e73a8af0-1d92c4dfcaamr4441907637.18.1729269830420; Fri, 18 Oct 2024 09:43:50 -0700 (PDT) Received: from hermes.local (204-195-96-226.wavecable.com. [204.195.96.226]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-71ea331195fsm1667528b3a.1.2024.10.18.09.43.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 18 Oct 2024 09:43:50 -0700 (PDT) Date: Fri, 18 Oct 2024 09:43:48 -0700 From: Stephen Hemminger To: Rajasekhar Pulluru Cc: dev@dpdk.org Subject: Re: Restrict max packet size on rx Message-ID: <20241018094348.4e91b6e5@hermes.local> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org On Fri, 18 Oct 2024 22:05:24 +0530 Rajasekhar Pulluru wrote: > Team, > Does setting mtu using rte_eth_dev_set_mtu limit the maximum size of the > packet received on the dpdk port to the configured mtu size? > > On an intel machine with ixgbe port, with mtu set to 1500, no rx-offloads > enabled, ixgbe dpdk port is able to receive packets greater than 1500 size > and even jumbo frames of size 9000, even though the peer is sending them > fragmented with mtu of 1500. > > How do I restrict the port not to receive any frame greater than mtu size? > > Appreciate any help, > Thanks. > Rajasekhar In networking, MTU and MRU are overlapping concepts. The MTU value is used as a hint to the driver as to what size buffer to allocate but it can use larger if it wants. If you have restrictions, then the application needs to enforce them.