Missing shared network

arturlinde

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Nov 3, 2017
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Hi guys. I have really weird problem. Will describe my setup first. I have modem—>router(tp-link) —> switch(3com24port)—> other router(extended network) and i have 4 computers connected to switch and camera.

The thing is that 3 computers connected true wifi has no problems they are always are online -visible for shared network but those computers connected true wire from switch occasionally disappears from list in fact when i try to disable shared folder it says one or two computers are connected if u disable sharing they will be disconnected and in fact i never tried to access this computer from network. On wifi laptop i didnt do nothing serious just share folder f, file printer sharing on. Just simple settings and its always online.
 
Solution
With respect to IP addresses ".1" at the end is not the same as ".100" at the end.

The following links should help provide further understanding:

https://www.lifewire.com/what-is-an-ip-address-2625920

http://home.bt.com/tech-gadgets/computing/what-is-an-ip-address-how-find-it-11363919925908

You should have only one device providing DHCP IP addresses. And the available DHCP IP address range should be set so as not to include 192.168.1.1

The DHCP IP address range could be established as 192.168.1.10 to 192.168.1.20 for example. Usually enough IP addresses to cover the number of expected devices plus a few more.

If the DHCP server is 192.168.1.1 and you have a router with DHCP disabled you could reserve and statically configure...

Ralston18

Titan
Moderator
You have two routers.

Be sure that only one router is providing DHCP IP addresses.

For most situations that would be the tp-link router connected to your modem.

What incoming port are you using on the "other router". Should be a LAN port and not the WAN port. I.e., 3com24port switch ---->[LAN] (other router) --->[LAN ports] ---> wired computers/devices and, if applicable, ~~~~~>wireless devices.

Would expect that the "other router" also has been assigned a static IP address via the main router (tp-link if that is indeed the case) with that static IP address being both outside of the DHCP IP address range allotted to the tp-link router and that static IP address is also reserved for the "other router" via its' MAC.

Make and model of the modem and "other router" could prove useful. As well as the model of the tp-link router.

Can you provide a simple network diagram and indicate the troublesome computers?



 

arturlinde

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Nov 3, 2017
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Just to make it clear! Second router i did assignt in the first router and that didn’t cure the problem. I never did that just straight after ur answer. Just did test. And all compiters see different amount of computers in network list. One pc see all pcs other see only three pcs other 4. Its a mess. I did reinstall win on all pc with same configurations. I change internet provider, router, cables. Aaaand im out of options.

Router(this router also have connected during say a lot of devices) —> switch. To switch connected four pcs. Also to switch connected other wifi router ddwrt—> phones,tv,ps3. Just to make clear my laptop is connected true wifi to second router and all pcs ALWAYS HAVE CONNECTION TO ME. Second router lynksis e900
 

Ralston18

Titan
Moderator
My recommendation is for you to take the time to draw out a map of all connected devices.

Then determine and add the applicable IP addresses for each device.

Use "ipconfig /all" via the Command prompt on each device to find its' IP address.

Also check each router: the router may or may not provide a list of connected devices.

Reinstalling Windows, changing IP providers, etc. is very unlikely to resolve the problems you are experiencing.

Unfortunately, I am finding it difficult to follow your posts. Not sure if English is your primary language or if some translation software is involved.

Are you using HomeGroup by any chance? Doing so may also further compliment things.
 

arturlinde

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Nov 3, 2017
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Yeah im a russian. From first router i could never see the second router as connected device.(so i went to second router and got mac and added it to first router dhcp reserved list).. do i need to assignt in any way first routers ip? Coz first router ip is 192.168.1.1 and the weird is that my phone for instance is connected wirelessly and phone ip will come up as 192.168.1.100 isn’t that the same ip? Router dhcp range is 100 -199 camera 199 ,second router 198 , pcs are 180-185. Is arp binding is anything to do with in in router settings? And homegroup shared folders yeah - just works fine.. a little update pcs connected wirelessly are always connected,problem is only with wired connection. Reinstalling windows just happened by like accident was never done and im new guy bla bla bla then upgraded to better inet and cables were old i decided to change. All that just happened chain reaction...)
 

arturlinde

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Nov 3, 2017
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a little update. my router 1 ip is 192.168.1.1 how come in dhcp new client list my laptop got automatically assignet 192.168.1.100 isnt that the same ip???
 

Ralston18

Titan
Moderator
Not the same IP. No more than "1" is the same as "100".

For the most part I would expect that the laptop would be assigned an IP address such as 192.168.1.100 (subnet mask 255.255.255.0).

Very common for most residential routers.

When the laptop is powered on one of first things it does is request an IP address. It sends that request to your router at 192.168.1.1. The router responds by providing a DHCP IP address based on the range of DHCP IP addresses allocated for use by the router.

In the cited situation your laptop was given 198.162.1.100. Next time the laptop logs on it may receive 192.168.1.102 (with "100" and "101") already being assigned.

Here is a reference tutorial:

http://www.steves-internet-guide.com/understanding-dhcp/

There are other such tutorials and explanations readily available online.

What can and does happen is that some error of commission or omission results in a duplicate IP address on the network.

Key is understanding the concepts involved and knowing how to correctly configure the network's router(s) and network connected devices.

Especially if you are using any Static IP addresses. If 192.168.1.100 has been assigned as a DHCP address and then your phone joins the network with a statically assigned IP address of 192.168.1.100 then you have an IP conflict.

A conflict may also occur if you have two routers both assigning DHCP addresses.

You can use "ipconfig /all" via the command prompt to view the configuration settings with respect to computers.

The router(s) may present some map or listing of connected devices and their IP addresses.

"arp -a" via the command prompt will list DHCP addresses in use.

Draw a diagram of your network and label the devices and IP addresses. For the routers look at the available DHCP IP address range and the presence of any statically reserved IP addresses. Usually reserved by the target device's MAC.





 

arturlinde

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Nov 3, 2017
7
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arturlinde

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Nov 3, 2017
7
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510
Ok. But why dhcp server gave laptop .1 at the end despite that router has itself .1 at the end.do i need to reserve in dhcp routers mac so in the future it keeps this .1 for the router ?
 

Ralston18

Titan
Moderator
With respect to IP addresses ".1" at the end is not the same as ".100" at the end.

The following links should help provide further understanding:

https://www.lifewire.com/what-is-an-ip-address-2625920

http://home.bt.com/tech-gadgets/computing/what-is-an-ip-address-how-find-it-11363919925908

You should have only one device providing DHCP IP addresses. And the available DHCP IP address range should be set so as not to include 192.168.1.1

The DHCP IP address range could be established as 192.168.1.10 to 192.168.1.20 for example. Usually enough IP addresses to cover the number of expected devices plus a few more.

If the DHCP server is 192.168.1.1 and you have a router with DHCP disabled you could reserve and statically configure the router to be 192.168.1.2.



 
Solution