I have a very strange network issue

[TechLarry]

And it has me totally baffled. This is my home network and I work from home.

Symptoms

File's I'm downloading are stored on a corporate gShare.

When download a large 10GB file from the corporate network, over VPN, about 30-75% of the way through the download my network goes dead. No computers have access, Tivo's fall offline, phones and iPads drop off line, etc... Tivo's are hard wired, computers are hardwired, iPad/Phone's are wireless.

Everything drops offline at the same time. It happens every single time I attempt the download.

I have NO problems downloading 4+GB ISO's from TechNet, or any other downloads.

I can move hundreds of GB of data over the network to my Server 2012E box with zero issues.

Here's an interesting point. Once this happens, I can't reach my Router's internal web server (192.168.1.1) it does not respond, from ANY device on the Network. A quick reboot of the router will not resolve the issue. Now, I know what you're thinking, because I did too. But hang in there...

Equipment

• Cox Cable, 30/4.
• Cisco Docsis 3 Modem.
• TrendNet 16 Port Switch.
• ASUS RT-AC66R Router.
• Cat5e and Cat6 Cabling.
• Standard Desktops and Laptops running Windows 7 and one running Windows 8.
• Wireless only used for phones and iPad.

What I've tried

• Thinking the router may be overheating and locking up, I swapped in two backup routers. A Netgear WNDR-3700, and a WNDR-4500. The problem repeated exactly as it did with the ASUS.
• Replaced all cabling.
• Bypassed the switch by plugging everything directly into the Router.
• Used a chicken foot to throw pigs blood on the office wall. Well, not really, but that's next.

Analysis

• If the problem was the Router, it should have been resolved by the (twice) swap-out of the router.
• If the problem was the Switch, it should have been resolved by the bypassing of the switch.
• If it was the Cable Modem, it should not affect my ability to hit the internal web server of the Router.
• If it was a cable, it should have been resolved by the replacement of all the cables.

Conclusion

None. I'm totally frickin' stumped at this point.

The only way I can get it back online is to power off everything (computers, router, switch, cable modem, etc...) and let it sit for 20 min or so. I can then light it all up and it's like nothing every happened. Unless I try to download the files from that gShare again.

 

[Orddie]

when this happens... what do the lights on the cable modem look like? I wonder if the cable modem is overwhelming your router with junk vpn stuff.

please confirm you have connected a PC directly to the modem, used vpn for the file copy, and still experienced the issue.

 

[XOR != OR]

Assuming the symptoms are consistent and accurate, I see two distinct and possibly related issues. The three suspects would be the VPN ( ipsec? ), the router and the modem. My hypothesis is that the modem creates separate "buckets" for the various ipsec protocols, and once overwhelmed the modem begins "tripping out", which may in turn send traffic to the router that wigs it out in turn.

Not unheard of, I've seen some strange things happen with home grade routers. But I would go back and verify your symptoms first. It is far more likely that something is weird there.

 

[TechLarry]

when this happens... what do the lights on the cable modem look like? I wonder if the cable modem is overwhelming your router with junk vpn stuff.

please confirm you have connected a PC directly to the modem, used vpn for the file copy, and still experienced the issue.

All lights on all equipment look normal.

Your suggestion of putting the corporate laptop directly on the Modem is a good one. I will try that tonight. The only reason I haven't done it is because the other points of the analysis tend to rule out the laptop and the cable modem (inability to access the router firmware from any machine).

I'm ready to try anything at this point

And yes. I really hate VPN overhead.

 

[TechLarry]

Assuming the symptoms are consistent and accurate, I see two distinct and possibly related issues. The three suspects would be the VPN ( ipsec? ), the router and the modem. My hypothesis is that the modem creates separate "buckets" for the various ipsec protocols, and once overwhelmed the modem begins "tripping out", which may in turn send traffic to the router that wigs it out in turn.

Not unheard of, I've seen some strange things happen with home grade routers. But I would go back and verify your symptoms first. It is far more likely that something is weird there.

I've been dealing with this for over a month now. In fact, the first thing I did was take the new ASUS router to Best Buy and have it swapped out with a new one. This was very early in the investigation. I was at 38 days since purchase, but they were very cool about swapping it for me anyway.

The symptoms are pretty darned solid and repeatable.

I've been leaning kind of in the same direction with it being some sort of weird VPN/Modem protocol/overload issue. You would think Cisco would know better if that's the case.

If my tests lead in that direction, I'll call the cable company and ask they verify I have the latest firmware. That should be fun LOL

Could this be a NAT pass-through thing? Obviously it's on and it works, but is there another setting buried in this ASUS I need to check?

 

[TechLarry]

I'm also trying to arrange for a co-worker to send me the exact same file from his home network. That will take the VPN out of the picture.

I'll create a web account on my server 2012E box and set up a drop box.

If it blows up, we know it's not a VPN issue.

 

[ND40oz]

I had all sorts of issues with my Comcast Cisco modem, internet would seem to drop randomly, although I guess looking at your issue, it may have been me doing stuff over the vpn that did it. I've since moved to an SMC gateway from comcast and haven't had any issues.

 

[TechLarry]

I had all sorts of issues with my Comcast Cisco modem, internet would seem to drop randomly, although I guess looking at your issue, it may have been me doing stuff over the vpn that did it. I've since moved to an SMC gateway from comcast and haven't had any issues.

My phone comes through the Cisco as well, so I may be limited in choices.

I'll wait and see how my non-vpn transfer test goes overnight. If I receive the 10GB ISO ok, I will then try the same download again with the COE Laptop connected directly to the Cable Modem using VPN. If it fails, we've found our culprit I think.

Now, getting Cox to do anything about it... That will be another story altogether

 

[ND40oz]

Oh, you have your phone service through Cox as well, sorry didn't realize that. I use Vonage for my home office service but if it's an all in one device you're probably stuck with what they give you.

I had tried different routers as well thinking they may be the problem, Netgear 3700 and a Time Capsule since the Apple was on the approved comcast list but neither made any difference. The SMC does routing if you want it to, but I still use the Time Capsule, just give it a static and it works fine.

Does Cox offer a business class service you could switch over to?

 

[TechLarry]

Oh, you have your phone service through Cox as well, sorry didn't realize that. I use Vonage for my home office service but if it's an all in one device you're probably stuck with what they give you.

I had tried different routers as well thinking they may be the problem, Netgear 3700 and a Time Capsule since the Apple was on the approved comcast list but neither made any difference. The SMC does routing if you want it to, but I still use the Time Capsule, just give it a static and it works fine.

Does Cox offer a business class service you could switch over to?

I guess I should note, the phone service isn't affected when the problem occurs.

They do have a business class service but I'm pretty sure the speeds are slower and the costs quite a bit more. I don't get reimbursed for my expenses so that's important.

 

[ND40oz]

Their phone service must not use their internet service then if it's staying up. I know what it's like to pay for business and not get reimbursed, but that's the price I pay not to have to go into the office every day. 50/10 with 5 statics comes out to almost $220 a month with comcast.

 

[TechLarry]

Ok, well the transfer of the 10gb file from the co-worker was a bust, but for different reasons.

I've learned that IIs in Serve 2012 has a 2GB file limit. There is a way to alter some settings to get 4GB, but that won't help me so why bother.

Sometime tonight I'll take the COE Laptop and put it directly on the modem, clear out the modems old MAC retention, and try to do the download. If it fails as before, then it's definitely in the Modem.

How that manages to comatose my router at the same time is a bit of a mystery though.