DHCP lease expired! No wifi.

  Jan Addis 14:55 13 Dec 2016
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Answered

My desktop computer suddenly decided not to access wifi. I have tried several things and then saw that the DHCP lease had expired on 11/12/16. I have no idea what this means, but I suspect it is the cause. Please can someone advise what I should do - simple instructions and plain English please as I am certainly not a tech! Computer is a Dell and wifi is from Sky router. My tablet seems to work ok. Thank you've so much for any help.

  Secret-Squirrel 12:10 01 Jan 2017

Strangely this morning the wifi is on, .............

Ah, that's good news. To make life easier for you, let's leave things as they are for now but get back in touch again if the problem does return and I'll be happy to help.

I notice that no one has suggested turning your Sky router off for a few seconds then turning it back on again. That simple tip frequently works miracles. Try it now, but if you keep having to do it, then again, get back in touch.

  Bazzaman 12:40 01 Jan 2017

A bit of background for you. DHCP stands for Dynamic Host Configuration Protocol.

Your router (i.e. your Sky box) uses DHCP to provide each of your devices with an IP (Internet Protocol) address (typically in the "private" range 192.168.0.0 - 192.168.255.255). In this case each such IP address is unique only WITHIN the realms of your home (local) network (assuming you only have the one router).

Typically a router provides a lease period for each allocated IP. Put simply, what that means is that once a device is allocated an IP it will keep that IP at least until the end of the lease period. Often you will find that when a lease has expired (this is ENTIRELY normal), the same device will pick up the same IP address again as the next available IP (from the 192.168.0.0 - 192.168.255.255 pool) is usually allocated.

The vast majority of the world uses DHCP and there isn't really a good reason to do otherwise (such as fixed IP addresses) for the vast majority of people.

The local network IP addresses should not be confused with the IP address your router is allocated (by Sky in your case). This latter IP address is GLOBALLY unique and is what differentiates your router (and hence your local network) from the entire rest of the world. Again these are typically dynamically allocated (I have a Sky Q router and the IP address changes whenever the router reconnects to the Internet). However there can be good reasons for wanting these IPs to be static (i.e. never changing) such as if one is hosting a website on your PC. But this also applies to very few people in the overall scheme of things.

  Secret-Squirrel 13:00 01 Jan 2017

The vast majority of the world uses DHCP and there isn't really a good reason to do otherwise (such as fixed IP addresses)....................

You've undermined the advice I gave Jan so please tell me why my advice isn't appropriate for a desktop PC.

Instead of overwhelming the user with masses of technical jargon (which she specifically said she didn't want), how about suggesting a fix for her problem.

  Forum Editor 13:12 01 Jan 2017

Let's not start bickering about who is offering the best advice - that isn't what we're here for.

Automatic dynamic addressing is the default for home networks, because it so easy - new devices are dealt with automatically as they attempt to join the network.

There are distinct advantages to having a static IP, but unless the user runs a mixed addressing configuration new devices have to be added manually, and that is something that is usually outside the average home user's experience.

If we're going to advise a static IP configuration it must be made absolutely clear that new devices will not be joined to the network automatically. A real pain when friends come to visit and want to use your WiFi network with their phones or iPads.

  Secret-Squirrel 13:31 01 Jan 2017

............new devices have to be added manually, and that is something that is usually outside the average home user's experience.

If we're going to advise a static IP configuration it must be made absolutely clear that new devices will not be joined to the network automatically. A real pain when friends come to visit and want to use your WiFi network with their phones or iPads.

What are you talking about Ed?

My fix for Jan's problem is simple. If needed, I will assign a fixed IP address to her desktop PC's wireless adapter. I can guarantee that it will not in anyway affect other users or devices.

I've done this loads of times and I know what I'm talking about.

  Forum Editor 23:13 01 Jan 2017

toejams

"Assigning one device with a Static IP doesn't mean turning off DCHP."

Having spent a number of years setting up commercial networks I'm well aware of that, which is why I made a reference to mixed addressing.

  Forum Editor 23:18 01 Jan 2017

Secret-Squirrel

"What are you talking about Ed?

Please stop overreacting (for the second time). I was addressing the post made by Bazzaman, I wasn't directing my comments at you. Your advice is fine, and i didn't suggest otherwise.

  Forum Editor 08:16 02 Jan 2017

toejams

Thanks.

Sixteen years of working in the forum has instilled in me the need for absolute clarity when offering advice. It isn't always easy, and sometimes what one writes is misunderstood.

  Jan Addis 19:12 02 Jan 2017

Whoops, seem to have caused a bit of a stir here, but so far internet is staying connected. Thank you all for your help - I am very grateful for your expertise and will be back if this or any other problems occur.

This thread is now locked and can not be replied to.

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