4 ms·

Never heard of this trick, I go to try it and... nothing. TFA may have some funky network setup to allow this. Also calling web browsers made by "stupid people

by chungy 2y ago

Never heard of this trick, I go to try it and... nothing. TFA may have some funky network setup to allow this. Also calling web browsers made by "stupid people" without even properly evaluating the effectiveness of your own network hack seems rather hypocritical. :)

lucb1e 2y ago
> [The Fine Article / OP] may have some funky network setup It is very common (or perhaps almost ubiquitous since most routers will respond, idk) to get responses and works by default for most devices. It will not work if you: - Have no IPv6 devices on your network - The hosts on your network have a firewall that filters the packets or configuration that disables pinging (I think Windows disabled ping by default since Vista) - You have some fancy network with host isolation (trading usability for security), often seen with enterprise vendors - It autodetected the wrong interface to send the packets out on. I don't know how ping does this, perhaps it tries to just send it everywhere. Can't quickly find it but the Arch wiki says you have to specify the interface (for me it works without, so clearly that's not exactly accurate, but I imagine it may not do what you want)
- Latty 2y ago
  On Arch, I get "ping: Warning: IPv6 link-local address on ICMP datagram socket may require ifname or scope-id => use: address%<ifname|scope-id>", and it doesn't work unless I do so.
  - lucb1e 2y ago
    Oh, interesting! Which ping have you got? Mine comes from the iputils-ping Debian package, which the man page confirms it's part of some broader iputils set of tools. I see there is also inetutils-ping which provides the same /bin/ping and /bin/ping6 commands, is that perhaps the one you've got? For anyone wanting to replicate this "provides" query on Debian, I use `apt-file search /bin/ping` to list what packages have a file with that name -- this will also match `/usr/bin/ping6` (both prefixes and suffixes will match) but that was fine in this case. (If you just do `apt search ping` or something, you get a huge list of any package mentioning the word ping, which may be what you want when searching for something more broadly; and if you use `apt search /bin/ping` it comes up empty because it doesn't have file path data.) Edit: now that I had looked up which utility it is, I figured I'd check the "is documentation enough" on how it finds which interface to use. It looks to me like it is `getaddrinfo` that decides it: https://github.com/iputils/iputils/blob/master/ping/ping.c#L648-L681 https://github.com/iputils/iputils/blob/master/ping/ping.c#L...
    - Latty 2y ago
      Yeah, I'm just using Arch's default iputils: > pkgfile $(which ping) core/iputils That doesn't provide a `ping6`, presumably as `ping -6` is the preferred solution.
  - aftbit 2y ago
    I tried this on Arch and it didn't work at all. $ ping -6 ff02::1%eth2 Did I miss some kernel tunable or nftables setting? Unicast ping works fine.
    - Latty 2y ago
      Do you have a link-local v6 address on that device? My first attempt `ping ff02::1%enp9s0` didn't work because I use VLANs and don't actually get addresses on the base device, using the VLAN virtual device (in my case `ping ff02::1%lan`) worked for me. You shouldn't need `-6`, given it's a v6 address.
      - aftbit 2y ago
        Yea I figured -6 was superfluous but I put it in because another commenter made a big deal out of ping vs ping6 (a distinction that's been gone in Arch for a while). I do have a link local address directly on that NIC. I also use VLANs sometimes, but none are configured right now on this link. Slightly edited below to hide my MAC but: $ ip -6 address show dev eth2 | grep link inet6 fe80::aef0:b837:fafa:fefe/64 scope link noprefixroute The same command works fine on my Debian and OpenWRT boxes, but not on my Arch desktop.
    - cchance 2y ago
      on osx it's .... ping6 -I en0 ff02::1 maybe different way to specify the interface
DanAtC 2y ago
Browsers not allowing completely valid URLs is stupid.
johnklos 2y ago
Is your result "nothing" because you 1) have IPv6 turned off, 2) are running a restrictive reverse firewall, 3) didn't pay attention to the fact that you likely have to specify your ethernet interface explicitly, 4) didn't notice that you need to use `ping6` instead of `ping`, 5) have device isolation on your wifi network, 6) any of a number of other things? You seem to be here to complain more than to actually learn, else you'd've said what results you got, and you'd communicate better by not using acronyms without context (TFA: trans fatty acids? Thanks for asking?) Regarding the comment about web browsers being made by stupid people, we're all allowed to have opinions. Most of the common web browsers have tons of stupid design choices, and generalizing that stupid design choices come from stupid people just sounds like a flippant remark, not a denigration of a whole group of people. The people I know who work on web browsers would wholeheartedly agree with the author's comment (I've heard many similar sentiments). The information in this article is useful, and everyone even remotely in IT would benefit by keeping this page bookmarked :)
- observationist 2y ago
  The context for TFA is this site; it's common knowledge.
- Arnavion 2y ago
  The Fine/Fucking Article. cf RTFM
- bhaney 2y ago
  > (TFA: trans fatty acids? Thanks for asking?) "The Fucking Article." Etymologically derived from "RTFM," but now mostly used as a casual abbreviation to refer to the article that a comment thread is about. People who have traumatic childhood memories of soap in their mouths sometimes pretend it stands for "The Fine Article" or "The Featured Article."
  - aftbit 2y ago
    Thanks! I have been on HN since 2014 and I still hadn't figured out WTF people were talking about with TFA. I just assumed it was some kind of reference to the article but I didn't realize the F was for fucking.
Latty 2y ago
The stupid people thing annoys me, because you see so much of "man, the people doing this must be stupid for not doing that" in so much conversation, which ignores the reality that so many things are outside of an individual's control, and I think blaming individuals rather than systems leads to a lot of bad systems hanging around forever unchanged, as it tends to become a thought-terminating idea, just "don't be stupid". Often, something is (seemingly) bad because of a lack of time or other resource, because a boss or standard told them to make it bad, because there is some bigger issue being avoided, etc... Especially when it comes to browsers, vendors are making trade-offs, and supporting a very rare case like this when URLs are often very sensitive security-wise seems like one I could understand being wary of. Does a user understand what devices they are connecting to in that situation? It's probably intended as a joking remark, maybe even an "all people are stupid" thing poorly done, but even so, I think it perpetuates a bad way of thinking about flaws in software.
- scrps 2y ago
  Since you are making valid points and being downvoted for the pleasure. The platform-specific nature of <zone_id> makes it difficult to impossible to validate the well-formedness of the URL (see https://tools.ietf.org/html/rfc4007#section-11.2 https://tools.ietf.org/html/rfc4007#section-11.2 , as referenced in 6874, to fully appreciate this special hell). Even if we could reliably parse these (from a URL spec standpoint), it then has to be handed 'somewhere', and that opens a new can of worms. https://www.w3.org/Bugs/Public/show_bug.cgi?id=27234 https://www.w3.org/Bugs/Public/show_bug.cgi?id=27234
- lxgr 2y ago
  Couldn't agree more. This sentiment is the fundamental attribution error [1] in a nutshell: "Others do stupid things because they're stupid, I do stupid things because stupid circumstances and other people made me" :) And while I can see that it's being used flippantly here and not intended as an insult, I still don't think it's fair to the many decidedly non-stupid browser devs out there. [1] https://en.wikipedia.org/wiki/Fundamental_attribution_error https://en.wikipedia.org/wiki/Fundamental_attribution_error

by chungy 2y ago

lucb1e 2y ago

> [The Fine Article / OP] may have some funky network setup It is very common (or perhaps almost ubiquitous since most routers will respond, idk) to get responses and works by default for most devices. It will not work if you: - Have no IPv6 devices on your network - The hosts on your network have a firewall that filters the packets or configuration that disables pinging (I think Windows disabled ping by default since Vista) - You have some fancy network with host isolation (trading usability for security), often seen with enterprise vendors - It autodetected the wrong interface to send the packets out on. I don't know how ping does this, perhaps it tries to just send it everywhere. Can't quickly find it but the Arch wiki says you have to specify the interface (for me it works without, so clearly that's not exactly accurate, but I imagine it may not do what you want)

Latty 2y ago
On Arch, I get "ping: Warning: IPv6 link-local address on ICMP datagram socket may require ifname or scope-id => use: address%<ifname|scope-id>", and it doesn't work unless I do so.
- lucb1e 2y ago
  Oh, interesting! Which ping have you got? Mine comes from the iputils-ping Debian package, which the man page confirms it's part of some broader iputils set of tools. I see there is also inetutils-ping which provides the same /bin/ping and /bin/ping6 commands, is that perhaps the one you've got? For anyone wanting to replicate this "provides" query on Debian, I use `apt-file search /bin/ping` to list what packages have a file with that name -- this will also match `/usr/bin/ping6` (both prefixes and suffixes will match) but that was fine in this case. (If you just do `apt search ping` or something, you get a huge list of any package mentioning the word ping, which may be what you want when searching for something more broadly; and if you use `apt search /bin/ping` it comes up empty because it doesn't have file path data.) Edit: now that I had looked up which utility it is, I figured I'd check the "is documentation enough" on how it finds which interface to use. It looks to me like it is `getaddrinfo` that decides it: https://github.com/iputils/iputils/blob/master/ping/ping.c#L648-L681 https://github.com/iputils/iputils/blob/master/ping/ping.c#L...
  - Latty 2y ago
    Yeah, I'm just using Arch's default iputils: > pkgfile $(which ping) core/iputils That doesn't provide a `ping6`, presumably as `ping -6` is the preferred solution.
- aftbit 2y ago
  I tried this on Arch and it didn't work at all. $ ping -6 ff02::1%eth2 Did I miss some kernel tunable or nftables setting? Unicast ping works fine.
  - Latty 2y ago
    Do you have a link-local v6 address on that device? My first attempt `ping ff02::1%enp9s0` didn't work because I use VLANs and don't actually get addresses on the base device, using the VLAN virtual device (in my case `ping ff02::1%lan`) worked for me. You shouldn't need `-6`, given it's a v6 address.
    - aftbit 2y ago
      Yea I figured -6 was superfluous but I put it in because another commenter made a big deal out of ping vs ping6 (a distinction that's been gone in Arch for a while). I do have a link local address directly on that NIC. I also use VLANs sometimes, but none are configured right now on this link. Slightly edited below to hide my MAC but: $ ip -6 address show dev eth2 | grep link inet6 fe80::aef0:b837:fafa:fefe/64 scope link noprefixroute The same command works fine on my Debian and OpenWRT boxes, but not on my Arch desktop.
  - cchance 2y ago
    on osx it's .... ping6 -I en0 ff02::1 maybe different way to specify the interface

DanAtC 2y ago

Browsers not allowing completely valid URLs is stupid.

johnklos 2y ago

Is your result "nothing" because you 1) have IPv6 turned off, 2) are running a restrictive reverse firewall, 3) didn't pay attention to the fact that you likely have to specify your ethernet interface explicitly, 4) didn't notice that you need to use `ping6` instead of `ping`, 5) have device isolation on your wifi network, 6) any of a number of other things? You seem to be here to complain more than to actually learn, else you'd've said what results you got, and you'd communicate better by not using acronyms without context (TFA: trans fatty acids? Thanks for asking?) Regarding the comment about web browsers being made by stupid people, we're all allowed to have opinions. Most of the common web browsers have tons of stupid design choices, and generalizing that stupid design choices come from stupid people just sounds like a flippant remark, not a denigration of a whole group of people. The people I know who work on web browsers would wholeheartedly agree with the author's comment (I've heard many similar sentiments). The information in this article is useful, and everyone even remotely in IT would benefit by keeping this page bookmarked :)

observationist 2y ago
The context for TFA is this site; it's common knowledge.
Arnavion 2y ago
The Fine/Fucking Article. cf RTFM
bhaney 2y ago
> (TFA: trans fatty acids? Thanks for asking?) "The Fucking Article." Etymologically derived from "RTFM," but now mostly used as a casual abbreviation to refer to the article that a comment thread is about. People who have traumatic childhood memories of soap in their mouths sometimes pretend it stands for "The Fine Article" or "The Featured Article."
- aftbit 2y ago
  Thanks! I have been on HN since 2014 and I still hadn't figured out WTF people were talking about with TFA. I just assumed it was some kind of reference to the article but I didn't realize the F was for fucking.

Latty 2y ago

The stupid people thing annoys me, because you see so much of "man, the people doing this must be stupid for not doing that" in so much conversation, which ignores the reality that so many things are outside of an individual's control, and I think blaming individuals rather than systems leads to a lot of bad systems hanging around forever unchanged, as it tends to become a thought-terminating idea, just "don't be stupid". Often, something is (seemingly) bad because of a lack of time or other resource, because a boss or standard told them to make it bad, because there is some bigger issue being avoided, etc... Especially when it comes to browsers, vendors are making trade-offs, and supporting a very rare case like this when URLs are often very sensitive security-wise seems like one I could understand being wary of. Does a user understand what devices they are connecting to in that situation? It's probably intended as a joking remark, maybe even an "all people are stupid" thing poorly done, but even so, I think it perpetuates a bad way of thinking about flaws in software.

scrps 2y ago
Since you are making valid points and being downvoted for the pleasure. The platform-specific nature of <zone_id> makes it difficult to impossible to validate the well-formedness of the URL (see https://tools.ietf.org/html/rfc4007#section-11.2 https://tools.ietf.org/html/rfc4007#section-11.2 , as referenced in 6874, to fully appreciate this special hell). Even if we could reliably parse these (from a URL spec standpoint), it then has to be handed 'somewhere', and that opens a new can of worms. https://www.w3.org/Bugs/Public/show_bug.cgi?id=27234 https://www.w3.org/Bugs/Public/show_bug.cgi?id=27234
lxgr 2y ago
Couldn't agree more. This sentiment is the fundamental attribution error [1] in a nutshell: "Others do stupid things because they're stupid, I do stupid things because stupid circumstances and other people made me" :) And while I can see that it's being used flippantly here and not intended as an insult, I still don't think it's fair to the many decidedly non-stupid browser devs out there. [1] https://en.wikipedia.org/wiki/Fundamental_attribution_error https://en.wikipedia.org/wiki/Fundamental_attribution_error