In a question I posted recently, I tried to include a link to a web page where the host is specified as a numeric IP address ( rather than a domain name. However, the Stack Exchange server won't let me. It blocks my question until I remove the link. It gives me the following error message:

Links cannot contain '' (try a nonnumeric domain or wrap in a code block)

I can easily imagine reasons why one might impose such a restriction. One is to prevent link rot. Another is to help people avoid posting links to malicious web pages, under the heuristic that any URL containing a numeric IP address is more likely to be malicious or not. That's completely reasonable. That heuristic is indeed probably almost always right and thus a net positive.

I'm certainly not complaining about the existence of such a filter; the link validator seems like, on the whole, a great thing. But in my case, it happens that the heuristic is wrong: I'm not linking to a malicious web page, and the web site has been around for at least 2 years so far, so there's no particular reason to expect it is any more likely to go away than any other blog on the Internet. In other words, the link validation mechanism has triggered a false positive. False positives are fine, but ideally it'd be nice if there is some way for me to work around the security mechanism when the mechanism has gone awry.

My question: Does anyone know of any way to work around the link validation and vouch for the link as good, so I can post my link as a clickable link? Or should I just live with it? If the answer is "live with it", well, I can live with that. I just want to make my question as clean and pretty as I possibly can, so if there's some way to make the link clickable, that'd be lovely.

What I've tried (and doesn't work):

  • The obvious way would be to post a link using a domain name, instead of a numeric IP address. However, in this case, the relevant web site does not seem to have any domain name that I can find; the only way I know how to reach it is via a numeric IP address. (Kinda lame on the website owner's end, I know, but not something I can do anything about.)

  • Another obvious reaction would be to omit the link from my question. However, in my case, the link is central to my question; omitting the link would be a huge omission.

  • A third obvious thing would be to find some other source for the information I'm trying to link to. However, I haven't managed to find any other equivalent source that I can link to instead.

  • I also tried adding HTML using HTML tags directly, instead of via Markdown (e.g., <a href="">....</a>). No joy: that's blocked by the filter, too.

Related (but not duplicates):

  • The link validator is overzealous and should allow posting so-called 'invalid' links - asks for the link validator to be removed or modified in general (whereas I have a more specific use case; and I am asking for tips for how to make my question as functional as possible, given the existing link validator, rather than asking for the link validator to be changed).

  • Are IP address links valid in posts? - explains the reasoning why numeric IP addresses are not allowed in links, but it does not offer any workarounds that are applicable for my particular situation (whereas I understand the general justification, but want to know what to do in one specific, unusual case where the justification does not hold).

  • If there were a way to work around it, what would be stopping spammers or those with malicious intent from working around it? – David Robinson Sep 25 '13 at 5:06
  • @DavidRobinson, that's a perfectly fair question! If you read the second link I shared (meta.stackexchange.com/q/131639/160917), the stated justification is broken links and link rot. I don't see any case where a spammer would maliciously post a broken link (not to mention that a spammer probably typically doesn't have > 10K rep). Thus my hope -- perhaps forlorn -- that there might be some way to vouch for my link and make my question more functional. That said, if it's not possible, it's not possible -- I completely understand. I just wanted to check.... – D.W. Sep 25 '13 at 5:10
  • I'd be inclined to say, in the general case, that if your question absolutely depends on an external link, there's a problem with your question. – Mat Sep 25 '13 at 5:55
  • @Mat, have you read the particular question that I linked to? I'd be glad for any constructive feedback you might have on that question. And, of course, if you see a problem with the question after reading it, I'd like to hear about it. (For the record, I didn't say that my question "absolutely depends on the external link". I said "the link is central to my question; omitting the link would be a huge omission". If you're curious what I meant by that, see the question that I linked to -- I invite you to form your own judgement about whether there's a problem with my question.) – D.W. Sep 25 '13 at 6:08
  • No, I hadn't. Not my comment was in the general case. The case you cite is extremely rare, I don't think it's worth it to implement something. – Mat Sep 25 '13 at 6:15
  • @Mat, right, I know, that's why I mentioned in the question that I wasn't asking for a change to the existing implementation -- I was just asking if anyone knows of a way to work around the restriction and add a suitable link to my particular question, while working within the constraints of the existing link validator. Or at least I thought I wrote that. Maybe I didn't make that clear enough? (I know I thought it loudly -- that's gotta count for something, right?) – D.W. Sep 25 '13 at 6:43
  • I read what you wrote, but it doesn't make sense if it's not a feature request. IP links are forbidden - you've found justifications for that. If there's an existing way around it, that would be a bug in the implementation of the validator, and either should be fixed, or that policy should be changed. Policy change is a feature request, whether that's just dropping that constraint on IP links or a new "process" to allow them in specific cases. – Mat Sep 25 '13 at 7:13

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