Kitz Forum

Internet => General Internet => Topic started by: Weaver on October 31, 2018, 03:43:45 AM

Title: Weird broken website
Post by: Weaver on October 31, 2018, 03:43:45 AM
This website - http://www.letmecheck.it/mtu-test.php - seems to work sometimes and sometimes I get a 404. Whatís going on with it?

Itís really useful, when it works, a site that tests the MTU of your internet connection.
Title: Re: Weird broken website
Post by: roseway on October 31, 2018, 06:57:23 AM
It returns a 404 for me at present.
Title: Re: Weird broken website
Post by: chenks on October 31, 2018, 07:59:51 AM
working fine for me
Title: Re: Weird broken website
Post by: roseway on October 31, 2018, 09:58:04 AM
Is this something to do with IPv6? I still get a 404, and it's shown as an IPv6 address.
Title: Re: Weird broken website
Post by: Weaver on October 31, 2018, 10:00:54 AM
This is indeed the weirdness. Chenks saw it. I have seen it on occasion. Now I am getting 404 So whatís going on?

Another thing.

If I go to a url made from the domain name with just a / or with nothing appended to it, ?I get the following nonsense:

This IP is being shared among many domains.
To view the domain you are looking for, simply enter the domain name in the location bar of your web browser.

Sounds like virtual hosting that isnít set up correctly? Would that be right?
Title: Re: Weird broken website
Post by: roseway on October 31, 2018, 10:16:00 AM
Quote
eric@great-tit:~$ whois letmecheck.it

*********************************************************************
* Please note that the following result could be a subgroup of      *
* the data contained in the database.                               *
*                                                                   *
* Additional information can be visualized at:                      *
* http://web-whois.nic.it                                           *
* Privacy Information: http://web-whois.nic.it/privacy              *
*********************************************************************

Domain:             letmecheck.it
Status:             ok
Signed:             no
Created:            2013-01-17 09:31:29
Last Update:        2018-02-02 00:56:15
Expire Date:        2019-01-17

Registrant
  Organization:     hidden

Admin Contact
  Name:             hidden
  Organization:     hidden

Technical Contacts
  Name:             hidden
  Organization:     hidden

Registrar
  Organization:     Realtime Register B.V.
  Name:             REALTIMEREGISTER-REG
  Web:              http://www.realtimeregister.com
  DNSSEC:           yes


Nameservers
  perans2.subnetonline.com
  perans1.subnetonline.com
  perans4.subnetonline.com
  perans3.subnetonline.com


eric@great-tit:~$
Title: Re: Weird broken website
Post by: parkdale on October 31, 2018, 10:22:48 AM
mmm.. works ok here
Title: Re: Weird broken website
Post by: Weaver on October 31, 2018, 10:29:52 AM
I am getting a 404 from Apache so my requests are at least reaching the server.
Title: Re: Weird broken website
Post by: d2d4j on October 31, 2018, 11:10:23 AM
Hi

This is indeed an issue specific to only IPv6 users.

IPv4 works lovely

I think it may just be a mapping issue of the IPv6 address to hostname but please consider this site looks as though it has not been updated in a few years or so and there is only 5 sites listed on that server IP for domain.

It maybe that IPv6 is only setup/used to test MTU for IPv6 and not mapped as IPv4 is for domain

Many thanks

John
Title: Re: Weird broken website
Post by: Weaver on October 31, 2018, 12:15:34 PM
This might explain why I have occasionally got it to work then, if my web browser is having a funny moment and its Happy Eyeballs (https://en.wikipedia.org/wiki/Happy_Eyeballs) routine chooses IPv4 in preference one day, for some reason.
Title: Re: Weird broken website
Post by: burakkucat on October 31, 2018, 04:48:00 PM
It works for me, IPv4, when I remember to enable ICMP echo on the WAN port.  :D

Quote
From the tests we did, we can assume that 1472 bytes is the largest unfragmented packet
size. The MTU size would be 1500, made up from 1472 payload and 28 ICMP/IP Headers
and payload information.

The maximum MTU size for W.X.Y.Z is:    1500

NB: The Internet Protocol requires that hosts must be able to process IP datagrams of at least
576 bytes (for IPv4) or 1280 bytes (for IPv6)
Title: Re: Weird broken website
Post by: j0hn on October 31, 2018, 06:06:18 PM
We've discussed before that letmecheckit completely fails to load with IPV6 enabled.

https://forum.kitz.co.uk/index.php/topic,21273.msg369502.html#msg369502

A huge fail considering their test has a specific IPV6 selection box. No good if the page doesn't load with IPV6 enabled.
Title: Re: Weird broken website
Post by: jelv on October 31, 2018, 06:24:13 PM
I've got it to work with IPv6 enabled and used it to test my IPv6 MTU on my Win 10 PC!

I put this into my hosts file:

Code: [Select]
141.138.203.105 www.letmecheck.it
which forced it to use IPv4 for the web page. Then I was able to put my router's IPv6 address in and test that.

Quote
From the tests we did, we can assume that 1430 bytes is the largest unfragmented packet
size. The MTU size would be 1478, made up from 1430 payload and 48 ICMP/IP Headers
and payload information.

The current maximum payload size is not divisible by 8.
The actual size of the payload (data) will be limited to: 1424
The maximum MTU size for 2001:8b0:xxxxxxxxx is:    1478
Edit: I did have to do a CTRL+F5 after I'd modified the hosts file.
Title: Re: Weird broken website
Post by: j0hn on October 31, 2018, 06:33:52 PM
enabling ipv6 on the network adapter after loading the website, then manually entering the ipv6 address and ruining the test also works.

A huge faf to not have a reachable ipv6 address, even if that needed to be added to a HOSTS file.
Title: Re: Weird broken website
Post by: Weaver on October 31, 2018, 10:39:05 PM
I emailed them using their web form. I notice it says that it is beta. It seems to have been beta forever though.
Title: Re: Weird broken website
Post by: Weaver on December 13, 2018, 05:23:05 PM
To fix the letmecheck.it problem with IPv6 I employed my Firebrick router to block IPv6.

I used the following rule, adding a rule element into the middle of an existing suitable rule-set that monitors outbound stuff coming out of my LAN "IF-LAN". You must change IF-LAN to be whatever your LAN interface object is called.

Code: [Select]

<rule-set source-interface="IF-LAN" no-match-action="continue">
      <rule target-ip="2a02:348:82:cb69::2" target-port="80 443" protocol="6" action="reject"/>
</rule-set>


But depending on your circumstances you might just roll the whole thing up into one combined form, as follows:

Code: [Select]

<rule-set source-interface="IF-LAN" target-ip="2a02:348:82:cb69::2" target-port="80 443" protocol="6" no-match-action="reject" />


But the first form is always preferable if you have an existing rule set to add this new rule into, as that way you can minimise the number of rule-sets, which is desirable from an efficiency point of view amongst other reasons. (Sed multa sunt peccata mea in re ista.)

This is not a great hack though because what happens when they change their IPv6 address, how many alternative addresses might there be due to load sharing, and how many other virtual http servers might be living on that box, so that other random sites could get knocked out just because they share that address?
Title: Re: Weird broken website
Post by: GigabitEthernet on April 23, 2019, 06:31:01 PM
Got this issue too.

Editing the hosts file doesn't work for me.

Although the page now loads I get a page that says

This IP is being shared among many domains.
To view the domain you are looking for, simply enter the domain name in the location bar of your web browser.
Title: Re: Weird broken website
Post by: Chrysalis on April 23, 2019, 08:03:00 PM
yeah this site has had issues for years.

The fact ipv6 has been broken so long suggests they dont care about maintenance, which makes me inclined to never use it, incase of the risk of a drive by or something.
Title: Re: Weird broken website
Post by: Weaver on April 24, 2019, 01:43:23 AM
Itís such a shame as it is incredibly useful. Maybe one of our number could replace it with a new similar tool.
Title: Re: Weird broken website
Post by: Chrysalis on August 19, 2019, 05:47:53 AM
ipv6 is finally working on this website now LOL.

Ok I did cheat, I accessed the page via ipv4, but manually inputted my ipv6 on the ipv6 test, I expect the ipv6 vhost is still broken to access the site.