From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14908 invoked by alias); 13 Jan 2016 21:20:54 -0000 Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Received: (qmail 11535 invoked by uid 89); 13 Jan 2016 21:20:52 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=0.2 required=5.0 tests=AWL,BAYES_50,KAM_LAZY_DOMAIN_SECURITY,RCVD_IN_DNSWL_LOW autolearn=no version=3.3.2 spammy=Assigned, inter, 1112, alberta X-HELO: smtp-out-no.shaw.ca Received: from smtp-out-no.shaw.ca (HELO smtp-out-no.shaw.ca) (64.59.134.12) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 13 Jan 2016 21:20:51 +0000 Received: from [192.168.1.100] ([96.51.88.197]) by shaw.ca with SMTP id JSqVawjQbsChYJSqWa2lPW; Wed, 13 Jan 2016 14:20:49 -0700 X-Authority-Analysis: v=2.1 cv=N9CJbzJB c=1 sm=1 tr=0 a=0g8qPGUHxEvai5om+WudJQ==:117 a=0g8qPGUHxEvai5om+WudJQ==:17 a=L9H7d07YOLsA:10 a=9cW_t1CCXrUA:10 a=s5jvgZ67dGcA:10 a=IkcTkHD0fZMA:10 a=PlQC-WsNAAAA:8 a=48vgC7mUAAAA:8 a=wiYxLJy5AAAA:8 a=_OZVCLxKcUsoy2RBpqAA:9 a=A_XxFGaD9uFszYNW:21 a=YOPH2fMOUwAIJf9-:21 a=QEXdDO2ut3YA:10 Reply-To: Brian.Inglis@SystematicSw.ab.ca Subject: Re: getaddrinfo fails with EAI_NODATA for some valid hosts with A records References: <20160108111408.GH20447@calimero.vinschen.de> <002701d14e24$49a2cbd0$dce86370$@comcast.net> To: cygwin@cygwin.com From: Brian Inglis Message-ID: <5696BFAF.4080908@SystematicSw.ab.ca> Date: Thu, 14 Jan 2016 09:17:00 -0000 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <002701d14e24$49a2cbd0$dce86370$@comcast.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-CMAE-Envelope: MS4wfEr/E3ifr0xziJ+q+nuJ5/a46yZyAbhu3yG8cKb14TzRlqvlaYEUYEkR1CajKhZOq+izjbOrKPEdAjhyv9R39WMBCaNDl+GNy7806LjVi6qsmKydqFyD aW2R9AtL2Y5cuqOCgmR5pFbLysi08UY++G5dXElPLKT9qOyjDs0PGOoOvApZ6/BcOUahqqL78VQ9dw== X-SW-Source: 2016-01/txt/msg00176.txt.bz2 On 2016-01-13 10:03, Andy Hall wrote: >> -----Original Message----- >> From: cygwin >> On Behalf Of Brian Inglis >> Corinna Vinschen writes: >>> On Jan 7 15:39, Brian Inglis wrote: >>>> getaddrinfo fails with err 7 EAI_NODATA for some valid hosts >>>> with A records. Err 7 EAI_NODATA is mapped from WSANO_DATA err >>>> 11004 in Windows. Can anyone reproduce failure with problem >>>> host name below? >>> Yes, I can reproduce it, and it's a total surprise. >>> I have no idea why Windows' getaddrinfo chokes on >>> leapsecond.utcd.org at all. >> Especially when after just one getaddrinfo call, the DNS cache is >> populated with: >> leapsecond.utcd.org >> ---------------------------------------- >> Record Name . . . . . : leapsecond.utcd.org >> Record Type . . . . . : 1 >> Time To Live . . . . : 600 >> Data Length . . . . . : 4 >> Section . . . . . . . : Answer >> A (Host) Record . . . : 244.34.36.97 >> so the DNS server is being contacted and responding normally, but >> it would appear Windows GAI is failing to use that info. Has this >> been reproduced on W10 so we can report this upstream? Is there any >> support without an account for upstream W7 reports? > DNS just translates URLs to IP addresses. It is no surprise that > works. However, addresses in the range 240.0.0.0 - 255.255.255.255 > are reserved. Windows is probably blocking that as a "favor". > Net Range 240.0.0.0 - 255.255.255.255 CIDR 240.0.0.0/4 Name > SPECIAL-IPV4-FUTURE-USE-IANA-RESERVED Handle NET-240-0-0-0-0 Parent > Net Type IANA Special Use Origin AS Organization Internet Assigned > Numbers Authority (IANA) Registration Date Last Updated 2013-08-30 > Comments Addresses starting with 240 or a higher number have not been > allocated and should not be used, apart from 255.255.255.255, which > is used for "limited broadcast" on a local network. > This block was reserved by the IETF, the organization that develops > Internet protocols, in the Standard document and in RFC 1112. The > documents can be found at: http://datatracker.ietf.org/doc/rfc1112 > RESTful Link http://whois.arin.net/rest/net/NET-240-0-0-0-0 See Also > Related organization's POC records. See Also Related delegations. See also IANA services and ports reservations which have been ignored since Windows devs got a connection to the world outside their PC (cough Citrix!) Reserved just means it won't be assigned, but as illustrated by my OP and Linux tests, it has been usable since CIDR/VLSM came in RFCs 1517-1519 in 1993, and routable since RFC 1812 in 1995 supported Classless Inter Domain Routing and Variable Length Subnet Masking. The private reserved address ranges are bogon territory for routers; the most that can be said about 240/8 is possible bogosity: that space is available for global internet use without any guarantees what devices, hosts, protocols, and services will interoperate. IANA considered releasing the 248M addresses for assignment a few years ago but decided it was not worth it, as it would only delay exhaustion of IP V4 space for 18 months, and some crufty old gear and stacks (cough Windows!) may not support it (as we saw and you said) for some functions. Regardless of that, the DNS lookup function should operate normally: implementing mechanism not policy; if some higher layer wants to apply a policy on use of those addresses, *THAT*'s what we have filters for. -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple