Path: csiph.com!news.mixmin.net!aioe.org!.POSTED!not-for-mail From: =?UTF-8?Q?Arne_Vajh=c3=b8j?= Newsgroups: comp.lang.java.programmer Subject: Re: Picking an unused port number Date: Mon, 6 Jun 2016 23:07:12 -0400 Organization: Aioe.org NNTP Server Lines: 44 Message-ID: References: NNTP-Posting-Host: 7SK6yTFfqwlIPNBLl3l7Qg.user.gioia.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Complaints-To: abuse@aioe.org User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.1.1 X-Notice: Filtered by postfilter v. 0.8.2 Xref: csiph.com comp.lang.java.programmer:34513 On 6/6/2016 9:45 PM, Jerry Stuckle wrote: > On 6/6/2016 9:28 PM, Arne Vajhøj wrote: >> On 6/6/2016 8:52 PM, Jerry Stuckle wrote: >>> On 6/6/2016 6:44 PM, Wayne wrote: >>>> On 6/4/2016 8:50 PM, Jerry Stuckle wrote: >>>>> On 6/4/2016 11:24 AM, nathanturner369@gmail.com wrote: >>>>>>> So, in general, is there any rule you should use when selecting a >>>>>>> port >>>>>>> number, other than picking one > 1024? >>>>>> >>>>> >>>>> Make it configurable, and > 4095, not 1024. >>>> >>>> Why? >>>> >>> >>> Ports 0-4095 are reserved. >> >> ???? >> >> 0-1023 are system ports >> 1024-49151 are registered ports >> 49152–65535 are ephemeral ports >> >> 80XX port numbers are very frequently used in the Java world. >> > If 1024-49151 are registered ports, then why would 80xx ports be used in > the Java world? Many possible reasons: - they may have been assigned to the Java purpose - they may have been assigned to a general purpose that is compatible with Java usage - they may not have been assigned yet > 0-4095 are generally considered "reserved" by commonly used protocols. > Others are used by other protocols, but not generally considered "in use". That is not how IANA looks at it. Arne