Network delay after waking from sleep

Setup is a Win 10 desktop with static IP connected with 1Gb Ethernet to a Ubiquiti ER-X router, connected to a Comcast modem/router in bridged mode.

Problem: after waking from sleep, it can take an annoying 30-60 seconds before Internet connectivity is available.

I have noticed that local LAN access is possible during this period even though WAN access is not.

I tried all of the usual steps; updating Windows, updating network drivers, disabling power management on the network adapters, various suggested registry tweaks and more. Some users reported similar symptoms caused by the Comcast XB6 modem which were solved by swapping the XB6 for a XB7. Mine was already an XB7.

I have finally solved the problem by connecting an unmanaged switch between the desktop and router.

I am very curious to understand the reasons for this re-connection delay and hear of any other more elegant solutions.

PCs in sleep mode can't always be tweaked the way you want them, or think you want them. Everybody has their own implemention of power saving.

For instance, I have tablet PCs where the onboad wifi is *always* in power saving mode, which cripples the ability to roam. Doesnt matter what I set in windows, The onboard USB / wifi is always in this mode until the manufacturer issues a firmware patch.

Since you put a unmanaged switch in the stream and it fixed the issue is obviously layer 2 or 3. Here's something to try - set up a continuous ping from your PC to the router. Now power cycle the switch. A simple dumb switch should quickly come back on and resume moving data. If it takes the same delay as happened before it's obviously a power issue with the router.

that is a bit perverse. That intranet traffic is fine eliminates most of the router powered down the port notions.

How are you testing internet connectivity? Are you going to a domainname that requires a DNS lookup, or have you also used a known IP address that would skip that concern?

And are you relying on the comcast router to provide DNS, or using one of the public ones like 8.8.8.8?

kelpdiver said:

that is a bit perverse. That intranet traffic is fine eliminates most of the router powered down the port notions.

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That's what I feel.

kelpdiver said:

How are you testing internet connectivity? Are you going to a domainname that requires a DNS lookup, or have you also used a known IP address that would skip that concern?

Click to expand...

Mainly I've been relying upon a simple browser check and the network indicator in the Windows system tray.

Obviously, I have a short window to conduct those tests after wake and login. But I will certainly test the status on some external sites by IP to exclude DNS issues.

kelpdiver said:

And are you relying on the comcast router to provide DNS, or using one of the public ones like 8.8.8.8?

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The Comcast modem/router is bridged. I use my own Ubiquiti ER-X router.

All of my systems are configured with 8.8.8.8 and 1.1.1.1.

Try a different cable. The main thing I can think of is if the router and NIC are trying to negotiate link speed and it's taking a long time to do so.

I've seen bad/long cables that are out of spec that can't negotiate anything automatically but work fine if manually set to gigabit or in worst cases, only work if I negotiate fast ethernet. You can also try setting the router port to run at gigabit manually to see if that helps. First, I'd try a different cable.

You can also skip the DHCP and set a fixed internal IP. Just make sure it doesn't conflict with something else.

rmexpress22 said:

Try a different cable. The main thing I can think of is if the router and NIC are trying to negotiate link speed and it's taking a long time to do so.

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I like this hypothesis.

You'd never notice if the broadband is well under 1gig.

But the router stats may show a high error rate, or worse, as you suggested, a lower link speed.

Thanks guys.

The machine is question has always been configured with a static IP so no DHCP issues at work.

The dodgy cable is certainly an interesting theory. I don't think it's the case here since the system normally works great at 1G. I'm traveling at the moment but will definitely try swapping out the cable as soon as I return home.