From owner-freebsd-net@FreeBSD.ORG Thu Oct 3 16:54:57 2013 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id 8B1A0AEE for ; Thu, 3 Oct 2013 16:54:57 +0000 (UTC) (envelope-from rysto32@gmail.com) Received: from mail-qc0-x22a.google.com (mail-qc0-x22a.google.com [IPv6:2607:f8b0:400d:c01::22a]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 4D85B2116 for ; Thu, 3 Oct 2013 16:54:57 +0000 (UTC) Received: by mail-qc0-f170.google.com with SMTP id m20so1860920qcx.1 for ; Thu, 03 Oct 2013 09:54:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=iTbEzewTe0kFsDyOa3SchO+NKQzdm1oiMbTcPN4i7eM=; b=Z/kKDhRC1Tz3bxK+MHkhJVoZVIWJFAmigEjIuPVRDyNlQYoElPjcol6Rf1vA0XwN1Z Px3SnVvif0Zp99440vku+EA9t35ySka+6HrIdLXDqW9xPp3ZiHYYX88msSMEgQY4lJgI S6OUpRaHgAtD1uH37NnIxITrfm0Coom0y11wpdJ1ak6+OocWwkwiBWjC2vgHkHJhM8kN y5M7r91TBDlsNkWDiqRt87b57V+/bZSstXqDRWHtKR5qIo/ANRJPMyyOlv5UsOhQp2k4 Jdc40S3Ha70BITwmDKND6xbKUN0adzzJRU5GxTHm9L8kWFXkOnHhKhexGqtxlT7C6nMF 8Buw== MIME-Version: 1.0 X-Received: by 10.49.51.67 with SMTP id i3mr11218165qeo.8.1380819296463; Thu, 03 Oct 2013 09:54:56 -0700 (PDT) Received: by 10.49.117.134 with HTTP; Thu, 3 Oct 2013 09:54:56 -0700 (PDT) In-Reply-To: References: Date: Thu, 3 Oct 2013 12:54:56 -0400 Message-ID: Subject: Re: The reason of "ping: sendto: No buffer space available" and link_irq variable From: Ryan Stone To: Tugrul Erdogan Content-Type: text/plain; charset=ISO-8859-1 Cc: freebsd-net X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 03 Oct 2013 16:54:57 -0000 On Thu, Oct 3, 2013 at 11:42 AM, Tugrul Erdogan wrote: > Hi, > > I am using FreeBSD alpha2 amd64 on my router and after packet loaded test > attack I am taking > "ping: sendto: No buffer space available" error when running ping from > router to victim directoion. The nic is "Intel 82599EB". Whenever this > problem began to show, I can track the packages by tcpdump but I think the > packages can not be created physically when they are reached physical > layer. Doing the nic down/up can not be solved the problem. > > When I testing I have found the "dev.ix.0.link_irq" value is increased very > differently from other nic's link_irq values. So after assigning the value > of 2 to this link_irq variable the problem solved. > > I want to your help at two path; firstly why should I take this error. > Secondly what is the role of the link_irq variable, what is the situations > which are trigger to increase the link_irq variable and is the real reason > of this problem the link_irq variable or anything else under this > mechanism? > > Thanks and best regards, dev.ix.0.link_irq is not supposed to be a writeable sysctl. It is a read-only sysctl that reflects the number of times that the hardware informed the driver (through an interrupt, or irq) that the state of the link changed. If you are seeing this increase then something is causing the NIC to lose link momentarily. I would recommend checking for things like dirty fibre, bad cables, failing optics (SFP+), etc. Check on both ends of the link.