[SOLVED] Cache issue or something else, couldn't resolve

JD007

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Jan 2, 2010
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18,530
I have some strange website access issue. On work, I can access the part of the website but few pages show forbidden access and can't access them. However, I can access those pages from home or from smart phone, as long as I am not on the work network.

Steps I have taken so far but did not resolve the issue:

  1. cleared the browser cache. and also used incognito window
  2. installed clean windows on one PC, even that PC couldn't access those pages
  3. flushed dns, (ipconfig /flushdns)
  4. replaced the router from TPlink to ubiquiti usg

total 5 PCs, all PCs, can't access the same pages, but can access other pages, including home page. from home or if I use Cell Data can access those pages. Do you think could be a problem with the modem (ISP). I am using ISP cable modem, which connects to USG router and to switch (netgear 24 port). What else I can do to resolve the issue, should I check with ISP or any other step I can do before contacting them?

Thanks in advance.
 
Solution
It might be a DNS cache in the hitron router. The simple thing is to reboot the router and see if the problem reoccurs.

If it does it could be the router itself or it could be the ISP.

What I would try is to change the DHCP server settings in the router. Most routers allow you to set the DNS it gives to the end client. The default is to give the end device the routers IP and the router acts as a proxy/cache to the ISP DNS server.

I would set the value to 8.8.8.8. or 1.1.1.1. You can also manually set this in the PC in the IPv4 network settings.

Another possibility is that you have IPv6 support at the office and it is not working correctly. It will run a mix of ipv4 and ipv6 addresses. IPv6 for some reason does not...

Ralston18

Titan
Moderator
Noted:

"On [At] work, I can access the part of the website but few pages show forbidden access and can't access them "

"as long as I am not on the work network."

Consider the nature of those inaccessible webpages - are they webpages that might/may only be available to select users or company staff versus the company employees in general or some public community?

= = = =

Thus I will ask an additional question: Have you raised the problem/question with the applicable IT/network staff at work?

You may be able to access the pages from home but that could be due to some weakness or gap in your home AV/malware protections.

Or the failed access could be a mis-configuration at work to where the restrictions and protections are too limiting or severe.

Could be (at work) just some failed or incorrect paths (URLs).
 

JD007

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Jan 2, 2010
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18,530
Thanks guys for the replies. Here are some of the answers to your questions.

I am the owner of the business and hence the IT person as well, not ideal but that is the case. There is no restriction to access to certain pages. This behavior is started overnight, a day before was no issue next days all PCs, started to show the same behavior. If I use wifi of the WORK network (TPlink archer c9) using it as access point and use the cell phone to acces those pages, staff and I can't access only certain pages, if we turn off the wifi and use the cell data, then all of us can access those restricted pages as well.

Staff can also access the pages outside the work network. USG is using the ISP DNS. I am wondering if there is a feature in the modem Hitron (provided by ISP), where some Cache is stuck at hardware level and somehow I need to flush it out.
 
It might be a DNS cache in the hitron router. The simple thing is to reboot the router and see if the problem reoccurs.

If it does it could be the router itself or it could be the ISP.

What I would try is to change the DHCP server settings in the router. Most routers allow you to set the DNS it gives to the end client. The default is to give the end device the routers IP and the router acts as a proxy/cache to the ISP DNS server.

I would set the value to 8.8.8.8. or 1.1.1.1. You can also manually set this in the PC in the IPv4 network settings.

Another possibility is that you have IPv6 support at the office and it is not working correctly. It will run a mix of ipv4 and ipv6 addresses. IPv6 for some reason does not work as well even though it has been claimed to be the future of the internet for 20 years. If there are options to disable IPv6 support in the router try that. You can turn off the IPv6 support in the end devices but when you have mulitple devices used by different people this is a painful way to do it.
 
Solution