Cable modem blinking out, sonic TZ350 ??
3Wizard
Newbie ✭
we have a small LAN running on Optimum Cable (Altice), no server, and the cable modem blinks out often and the firewall reports lost connection WAn. We have replaced cables coming from the building closet to the modem, replaced the modem, replaced the UPSs, replaced the Sonicwall (this is new), and we even went as far as getting a new set of static IPs from our internet provider (thinking it may be a DOS attack). still, the modem loses its connection. Optimum has even put us on a new connection in the closet. still, the modem simply blinks out for a few seconds, then it resets which takes about 3 minutes. Optimum seems to point to the firewall and our tech guys seem to be pointing at Optimum. Other tenants don't seem to be having this issue and our line in the telephone closet I believe goes to four or five other tenants. some of our employees do access their computer at the office from home via a VPN. Any thoughts or similar experiences?
Answers
I have seen where a large amount of traffic will 'overload' a cable modem and cause it to reboot itself. This was a a few years ago with an Arris brand modem I believe. It took much effort to get the cable company to admit the issue.
Have you tried / requested a completely different brand of modem?
they are coming tomorrow and I asked them to bring a different one if they can
Hi @3Wizard
This is most likely due to the ISP infra not being to able to handle the load and they wont admit that and instead they will blame on your router/modem or some splitter and replace those, which will not fix the issue.
so yesterday they installed a test modem with nothing attached just to see what happens when we blink out again. our main modem went down but the test modem stayed running. This shows me the ISP lines coming in are fine as the test modem kept running. Yesterday at 5:20 pm est (NY) we unplugged this firewall power until this morning around 8 am. OUR ISP reported no loss of signal and no modem reboot from yesterday afternoon. We then plugged the Sonicwall back in and, bingo, within a short period of time we lost signal on our main modem.
We set up a basic SonicWall, loaner T3200, from our tech consultants yesterday and were good for about 24 hours and now having issues again with the ISP modem blinking out multiple times per day. Could this be an issue for us? https://www.sonicwall.com/support/product-notification/sonicwall-dos-xss-vulnerabilities/201015132843063/
I believe the ISP is coming tomorrow to possibly replace the modem for the second time.
You haven't mentioned the Sonicwall locking up / rebooting itself when the internet is lost. If that is happening then you may be affected by a vulnerability (but very unlikely if this happening on different models / hardware).
Can you get a different provider?
the Sonicwall isn't locking up or rebooting, just the modem blinking out, losing the signal. This is our second ISP modem, and they are scheduled to come today and give us a third ISP modem just to be sure
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so our ISP has been making some firmware upgrades with the modem manufacturer. yesterday they even replaced the modem with updated firmware. so far so good, but we need about a week of uptime to declare victory.
yesterday was the first time in 4 1//2 days our ISP modem reset. ISP changed the firmware on a new modem. I am still skeptical if there is some kind of conflict between the sonicwall and the ISP modem. The firmware they installed acts better with VPNs the ISP says. Something after the ISP must be causing some kind of feedback back to the ISP modem that causes a modem reset.
ISP wont admit their mistakes / issues.
Their 'responsibility' is based on their contract / SLA with you. If they cannot meet their contract / SLA than you have reason to look elsewhere or litigate.
Hate to resurrect an old thread, but we currently have a client suffering the same issue. We have tried the same troubleshooting steps as well. Did you ever find a solution?