Need some help from someone smarter than me with an odd network issue

[Revelstone77]

A little background, I was on ATT and was having issues with my work computer ( i work from home via their VPN) where i could connect to the office and do some things, like email. But other services would time out. One trip to the office, i met up with the support folks and they put my laptop on a dirty port to the internet and all was fine. I came home and plugged my laptop into one of the ports on the ATT gateway instead of coming off my AC86U and all was fine, for several years. The problem is, i forgot about that special setup for the work laptop and switched to Xfinity, for more bandwidth and less money and now I'm back to the laptop not working properly again. Today, I factory defaulted the router and put just enough config back in to get connectivity and tried it with no luck. All the other devices in the house work flawlessly. I'm pulling whats left of my hair out over this. My next step is to plug the laptop directly into the cable modem and see if that works. If it does, could I put a switch in between the modem and the router and tap off for the laptop or will the modem not allow two mac addresses?

 

[L&LD]

A little background, I was on ATT and was having issues with my work computer ( i work from home via their VPN) where i could connect to the office and do some things, like email. But other services would time out. One trip to the office, i met up with the support folks and they put my laptop on a dirty port to the internet and all was fine. I came home and plugged my laptop into one of the ports on the ATT gateway instead of coming off my AC86U and all was fine, for several years. The problem is, i forgot about that special setup for the work laptop and switched to Xfinity, for more bandwidth and less money and now I'm back to the laptop not working properly again. Today, I factory defaulted the router and put just enough config back in to get connectivity and tried it with no luck. All the other devices in the house work flawlessly. I'm pulling whats left of my hair out over this. My next step is to plug the laptop directly into the cable modem and see if that works. If it does, could I put a switch in between the modem and the router and tap off for the laptop or will the modem not allow two mac addresses?

Are you saying that the 'dirty port' you were using on your laptop was a direct connection to the internet with no router in-between? And then you used that when you used the laptop at home, for years?

What isn't working exactly? What laptop os are you running? Why isn't your workplace helping you with this?

 

[ColinTaylor]

I came home and plugged my laptop into one of the ports on the ATT gateway instead of coming off my AC86U and all was fine, for several years.

I assume this is something of an exaggeration as the RT-AC86U hasn't been available for "several" years? That aside, what kind of VPN client are you using? Have you spoken to your IT department about this? Your public IP address will now be different so maybe they need to do something their end.

 

[Revelstone77]

I assume this is something of an exaggeration as the RT-AC86U hasn't been available for "several" years? That aside, what kind of VPN client are you using? Have you spoken to your IT department about this? Your public IP address will now be different so maybe they need to do something their end.

My AC87U was where it all started. Then migrated to the 86. The Cisco VPN client connects just fine. I get access to some things, but other services wont connect. Corp IT said they had no way of troubleshooting my home network. The fact that Corp IT could connect my laptop to a dirty port and connect with VPN ruled out a laptop problem. By connecting my laptop to one of the eth ports on the ATT gateway, bypassing my router, it worked just fine. I need to get it working with Xfinity now and it doesnt look like I can get it working through the router unless someone has some idea. Is it possible to insert a "tap" between the cable modem and the router so i can plug the laptop in there?

 

[ColinTaylor]

Cable modems normally only support one device and therefore they only have one WAN Ethernet socket. There are some ISP's that allow you to have multiple WAN connections but in that case the modem they supply usually has more than one socket. You'd need to check with your ISP.

As for your problem, it seems strange that only some services are effected. The only thing that comes to mind is that maybe there's a conflict with the IP addresses used for your local network and the remote network(s). What is the LAN IP address and subnet mask set to on the router (LAN > LAN IP)?

 

[Revelstone77]

Cable modems normally only support one device and therefore they only have one WAN Ethernet socket. There are some ISP's that allow you to have multiple WAN connections but in that case the modem they supply usually has more than one socket. You'd need to check with your ISP.

As for your problem, it seems strange that only some services are effected. The only thing that comes to mind is that maybe there's a conflict with the IP addresses used for your local network and the remote network(s). What is the LAN IP address and subnet mask set to on the router (LAN > LAN IP)?

Local network is 192.168.x.x class C and Corp is all 10.x.x.x. The odd thing is when i travel and connect through the hotel network I have no problems. I'm tempted to pick up different router, Linksys or Netgear, just to try it outand see if it makes a difference. Would hate to give up my AC86U and Merlin's code, but i have to work...

 

[ColinTaylor]

You said "other services time out". What kind of services are they and what error messages do you get? Maybe that can provide a clue. e.g. Is it timing out trying to resolve name (DNS), or maybe it can't connect to a socket on a server?

I asked about the IP addresses because before you were probably double NATing, with the ATT probably using 192.168.0.x and the Asus using 192.168.1.x. It might be worth changing your LAN addresses to 192.168.0.x and see if that works.

 

[Revelstone77]

You said "other services time out". What kind of services are they and what error messages do you get? Maybe that can provide a clue. e.g. Is it timing out trying to resolve name (DNS), or maybe it can't connect to a socket on a server?

I asked about the IP addresses because before you were probably double NATing, with the ATT probably using 192.168.0.x and the Asus using 192.168.1.x. It might be worth changing your LAN addresses to 192.168.0.x and see if that works.

They are web based applications. DNS appears to resolve, the tab in the browser takes on the App name, but then the link times out and cant connect.
I have the ATT gateway in passthru mode so it shouldnt have been double NATing, but I will try setting to 192.168.o.x to see if it makes a difference.
BTW, thanks a bunch to you and L&LD for taking your time to help.

 

[dave14305]

They are web based applications. DNS appears to resolve, the tab in the browser takes on the App name, but then the link times out and cant connect.
I have the ATT gateway in passthru mode so it shouldnt have been double NATing, but I will try setting to 192.168.o.x to see if it makes a difference.
BTW, thanks a bunch to you and L&LD for taking your time to help.

Do you think your IT department set any static (persistent) routes on your laptop? Any Persistent Routes listed if you run "netstat -rn"? Seems like it will be hard to solve unless you know why the old setup worked. But I like a good mystery.

 

[Revelstone77]

There is no -m switch on netstat but i ran a route print and it shows none under persistent routes