Internet dropping - ripping my hair out

scottay

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Reno, NV
Hi all,
I'm dealing with a very annoying network issue. My client is randomly dropping internet throughout the day. Sometimes only once, sometimes 2-3 times a day. If we let it sit, it doesn't seem to come back on its own. When we reset the modem, it rarely comes back online. When we reset the router, it always comes back online. This tells me it's most likely router related.

Here's a little info that may help:
Router: Cisco RV320.
ISP: Charter, static IP
Server 2012 R2 Essentials is acting as DHCP and DNS, Cisco router is set to DHCP relay to the server.

Everything has been running perfect for a year. The ONLY thing that changed is they hired a new employee. This new employee is using his own Macbook. Shortly after he started, they were experiencing wireless issues. As a way around it, he decided to get internet access to his laptop via his cell phone. Following that, massive network issues arose. I traced that down to the setting his Mac was using to pull internet from his phone - it was acting as a DHCP server, so the company's server decided to shut down DHCP services. Turning off that setting resolved that issue, and all seemed fine. The next day, the internet began dropping again. The local LAN works perfectly, just the internet is dropping out.

I've called Charter, they swear it isn't them.
I've upgraded the firmware on the router.
I've double/triple checked the DNS configuration on the server - can't spot anything.
Reading countless Cisco forums I discovered a threat discussing a setting that could be causing the router to try to "load balance" to the second WAN even with nothing connected, so I tried changing those settings.

My next step is to factory reset the router and reconfigure it. It's a very simple network, it won't take more that 5 minutes.
Following that, since it's a dual WAN router I was thinking of configuring the other port. My thinking is maybe there's something messed up with that port.

It just seems WAY to coincidental that all this just magically starts acting up as soon as this new employee started working with them. It's not impossible, anything is possible with electronics... This environment is all brand new, I completely started from scratch just about a year ago. I have about 15 of these Cisco routers in the field, including 2 of my own, and I've never seen any of these issues. Can anyone think of anything this Mac might be doing to crash the network? Or maybe something else I can do besides waste money on a new router when it may not be the problem?
 
Hi.
Does the router have the latest firmware update ?

Could there be an IP address issue ?

Perhaps setup the machines with static ip addresses to see if that resolves things.

From the op, it appears the origin may have been DHCP related. Is upnp running ?

As a test, temporarily kill all the security. See if that has an effect.

Your original idea though, to reset the router is probably the best option.
 
I would try swapping one of your own known-good routers with theirs, just to see if the problem resolves or follows the router. I've had some routers (residential Cisco) drop out randomly because of an intermittent hardware failure (the AC adapter, IIRC).
 
What do you mean by "cisco router is set to DHCP relay to the server"?

First, I would run steady diags from the server, or a workstation...to see where the failure actually is.
*Run a ping -t to public FQDN...like www.google.com....to test internal DNS. Maybe DNS is failing...and when the internet appears down...connectivity is still there ..you just can't resolve names.
*Run a ping -t to a public IP address, like 208.67.222.222 (an OpenDNS server).
*Run a ping -t to the LAN IP of the modem/gateway (you may have to plug a node in behind this with an IP in it's range to do this...depending on what the modem/gateway is)
*Run a ping -t to the LAN IP of the router.
 
Everything has been running perfect for a year. The ONLY thing that changed is they hired a new employee. This new employee is using his own Macbook. Shortly after he started, they were experiencing wireless issues. As a way around it, he decided to get internet access to his laptop via his cell phone. Following that, massive network issues arose. I traced that down to the setting his Mac was using to pull internet from his phone - it was acting as a DHCP server, so the company's server decided to shut down DHCP services. Turning off that setting resolved that issue, and all seemed fine. The next day, the internet began dropping again. The local LAN works perfectly, just the internet is dropping out.

Ok explain further this mac setup? So Mr Mac sets up his wifi to connect with your network and it all goes in the tank? So he started using his phone? So he was connected to his phone AND your internal network? Both by wifi? (That's not possible....)
 
X2 what Larry said. Don't over-think this. Swap in another router. If that doesn't do it than start digging deeper.
 
Morning all. Thanks for the replies.

Yes, the router is running the most current firmware.

I'll try some of the ping tests. I had all those pings going for an entire day to see if I could isolate it, but the internet never dropped that day. I'll fire them up again.

I reset the router and reconfigured earlier this morning. If that doesn't solve it I'll throw a test router in.

By "cisco router is set to DHCP relay to the server" I mean that the setting under the DHCP section is set to forward DHCP requests to the server. The router doesn't handle DHCP, the server does.

Regarding the Mac, no, he wasn't connected to both wireless connections. He was hardwired to the network and had his wireless connected to his phone. For some reason the server saw this and thought that his Mac was responsible for DHCP, so it shut down the services. I found this because I tried to connect to the wireless and was given an IP on a completely different subnet. He disabled whatever setting was doing this and all those problems went away.
 
By "cisco router is set to DHCP relay to the server" I mean that the setting under the DHCP section is set to forward DHCP requests to the server. The router doesn't handle DHCP, the server does.

Oh...for the mobile/remote VPN clients.....
For the standard LAN shouldn't need that...I disable DHCP on the routers for the LAN.
 
It is a laptop, so he takes it home at night. He had it over the weekend, and they went down again... So I assume that it's not directly the Mac's fault. I'm still left scratching my head why everything works flawlessly for a year, then the week they bring someone new on it all goes down hill.

After resetting the router yesterday I've been keeping an eye on the environment. They had a brief hiccup mid-day yesterday. Also a couple throughout the evening/night. It seemed to drop for 20-30 seconds then come back up. I'll be watching it throughout today, and will throw in a temporary router if they go down. Even these little drops aren't normal, something has to be up.
 
Have you tried using google's DNS servers instead of your ISPs default ones? I had an issue with AT&T one time where the internet wasn't actually going down, it just couldn't resolve host names like Bertie had mentioned.
 
When I reconfigured the router I used Google DNS. Before I think I had them set to the ISP's.

So, maybe coincidentally, after firing up the syslog and utilizing a pig tracking software (pinging the modem, router, Google DNS and the server) they haven't gone down at all today. 11 hours of up time.. This is longer than I've seen for quite a while. Hopefully I didn't just jinx it! But, this got me wondering if something is timing out somewhere and knocking them offline. Having constant pings (every 10s) might be keeping something alive somewhere?? It I don't get any disconnects by later this evening or tomorrow morning, there's has to be something that the pings are "fixing."
 
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