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-   -   Superhub : Odd router setting blocking site access? (https://www.cableforum.uk/board/showthread.php?t=33701172)

Kushan 03-08-2015 20:16

Re: Odd router setting blocking site access?
 
Quote:

Originally Posted by Allium89 (Post 35791829)
Trys that. No change there I'm afraid. Think I tried that and changing the DNS when I was first looking some while back.

Okay that's interesting. I know what Igni is getting at and was going to be my next suggestion.

Here's the thing - there's a chance that your router got unlucky and happened to get a DHCP lease with a bad configuration. Just pure bad luck that could have happened to anyone.

However.

The fact that other devices are getting good leases and when you clone the mac of your PC, you're still getting a bad subnet, suggests that the router is at fault. There's no reason the DHCP server at Virgin would be handing out a good config and a bad config to the same MAC.

Unless you can override that, I think your router needs to be replaced.

General Maximus 03-08-2015 20:34

Re: Odd router setting blocking site access?
 
ya, especially as it is working on the shub out of all things (twilight zone)

Allium89 03-08-2015 21:12

Re: Odd router setting blocking site access?
 
So, I've cracked it. I think!

Firstly the router page I said was called "Static Routing Table" is just actually called "Routing Tables" and appears to populate from the DHCP as in previous posts.

There is however another page below called "Static Route" which allows you to input your own routes. But how do you know what?

Well a bit of logic and trial and error, I tried this,

81.0.0.0 255.0.0.0 81.110.180.1

Now the routing table says,

Destination IP Subnet Mask Gateway Metric Interface
192.168.0.0 255.255.255.0 0.0.0.0 0 br0
81.0.0.0 255.0.0.0 81.110.180.1 0 eth2.2
81.0.0.0 255.0.0.0 0.0.0.0 0 eth2.2
0.0.0.0 0.0.0.0 81.110.180.1 1 eth2.2

Low and behold I can now access the site! I think I have now forced any 81.xx addresses to be routed to the Virgin gateway. Remove the static route and it fails again.

So, is this the right way to do it? What else may it break? Presumably it will only last as long as this lease holds and then a new gateway is set? And still, where does the original 81.xx route come from and why? Is this just a grade A kludge?

Your last post Kushan, got me thinking again to have another look.

Many thanks for all your inputs, happy to have any more clues as to why.

Every day is a school day, they say. This networking malarkey is easy isn't it? /runs and hides/

General Maximus 03-08-2015 22:10

Re: Odd router setting blocking site access?
 
it isn't going to break anything because all it is doing is telling everything to go to the cmts which is what it should be doing anyways

qasdfdsaq 04-08-2015 14:11

Re: Odd router setting blocking site access?
 
Quote:

Originally Posted by Ignitionnet (Post 35791814)
You could do worse than cloning the MAC from the network card of the PC you used :)

Quote:

Originally Posted by Allium89 (Post 35791829)
Trys that. No change there I'm afraid. Think I tried that and changing the DNS when I was first looking some while back.

It'd be better to do it the other way round. Copy the WAN MAC of your router to your PC's network card.

You should then get the same IP as the router got, and the subnet mask you receive in that situation will confirm if the router or VM's network is the issue. Though I guess it's fairly obvious already.

---------- Post added at 13:11 ---------- Previous post was at 13:10 ----------

Quote:

Originally Posted by General Maximus (Post 35791872)
it isn't going to break anything because all it is doing is telling everything to go to the cmts which is what it should be doing anyways

Well technically it's still a broken routing table. And a device that ignores the subnet mask in a DHCP lease is... broken.

Allium89 04-08-2015 15:56

Re: Odd router setting blocking site access?
 
Quote:

Originally Posted by qasdfdsaq (Post 35791938)
It'd be better to do it the other way round. Copy the WAN MAC of your router to your PC's network card.

You should then get the same IP as the router got, and the subnet mask you receive in that situation will confirm if the router or VM's network is the issue. Though I guess it's fairly obvious already.

---------- Post added at 13:11 ---------- Previous post was at 13:10 ----------



Well technically it's still a broken routing table. And a device that ignores the subnet mask in a DHCP lease is... broken.

Well that took a bit of fiddling to find, but I think I managed it, at least ipconfig reported the MAC address changing. However the end result seemed to be that it still need the extra static route to make it work.


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