Internet dropouts and address conflicts - will static IP's resolve this?

Growly

Reputable
Feb 11, 2016
2
0
4,510
Hi there, I need a bit of help as I'm getting slightly out of my depth now with a big project. I took it upon myself to wire up my housemates internet for them, but I live in an old office building with 37 people, spread over 6 floors and 3 door numbers long. It's been quite a mission but my cabling seems to have been done very well and so mostly I've been able to get everyone their internet.

My issue is we are now having ip address conflicts and dropouts on the network. I will explain my set up precisely in a moment, but I would appreciate any help anyone could provide me on this cos I'm not so good with networking as I am with wiring up cables.

We have installed 4 phone lines into the building, each with their own number, so they are not bundled together to increase speed or anything.

Each line has it's own router. 3 lines are with Talktalk (UK) and 1 with BT and use their branded routers. The Wi-Fi from these boxes works pretty well usually but only a couple of people are in range as the routers are in the old server room in the basement. From there, I have traced cables all over the building or run new ones where they were severed when the old office cleared out. I have tested all my cabling so far and not uncovered any faults. I have used ethernet cables in the LAN ports on the back of these to get internet to other routers or mini routers.

Line 1 has 1 cable connecting to a Belkin router in my room for wired PC internet and also for wireless, to which multiple devices connect. Line 1 also connects to a Wi-Fi mini router Wireless-N 802.11n (like the Satechi, though mine is unbranded). This has been configured to act as an Access Point, using a unique SSID and password. Multiple users connect to this unit by Wi-Fi. There is a second identical mini router in proximity to this one configured in Repeater mode with the same SSID and password to help extend the coverage in this large area.

Line 2 presently has 4 ethernet cables plugged into it and connects to 4 mini routers in Access Point mode, each with their own unique SSID and passwords.

Line 3 currently runs to a single mini router unit accessed by multiple users. It has its own unique SSID and password.

Line 4 currently runs to 1 mini router in access point mode, 1 standard router and to one wired access point for plugging into the computer.

Slightly complex I know.. but all networks are experiencing IP address conflicts, some more frequently than others, with several users frequently not being able to get back online for hours. I have not changed any of the default settings on the routers. As far as I know the Master Routers in the basement come with DHCP automatically enabled. The Belkin router extention has DHCP enabled too. I cannot remember if the mini routers also have DHCP enabled or if they come with static IP's.

How do I eliminate the address conflicts that are booting people off the network and leaving them disconnected for a few hours at a time?
Should the master routers have static IPs and leave the extensions to handle DHCP assigning or should it be the reverse and leave DHCP duties solely to the Master Routers connected to the phone line and then set Static IP ranges for each extension in access point mode?

Edit: I also want to avoid having to do any special programming on every users device that needs to access it as there would be well over 80 devices I would need to programme and I have no idea how to do that on MACs, while the Windows and Android devices would take forever.

I'd REALLY appreciate any help on this! =)
 
Solution
The device giving out IPs via DHCP must have a static (internal) IP; all others should not. If each master router has its own separate network, you shouldn't need to change the IPs.

Most likely, each mini-router is giving out IPs in the same space, so you're getting multiple devices with the same IP. Turn off the excess DHCP servers, then wait a day or two for all the bad leases to expire.

Loads of users could cause drop-outs and slow speeds, but you wouldn't get IP conflicts. Unless you had more than ~250 devices per network, then you might run out of IPs... but it sounds like you top out at 37, so even with five per user you should be fine.
Only one device in a network should ever have a DHCP server enabled. If you're using consumer gear, this should be the device connected to the internet.

If you want to use multiple internet connections, either physically separate them (no cables connect from network 1 to network 2), or you can do some rather tricky enterprise stuff (either VLANs or round-robin which gateway is given out). I strongly suggest you just separate them.
 

Growly

Reputable
Feb 11, 2016
2
0
4,510


Thank you for your reply. So I did wonder about DHCP being enabled on multiple devices on the network. That's helpful, I can make sure that only the master routers have this enabled. I'm not certain if the mini ones do or if they come disabled by default. Assuming they are disabled and I am still having problems with a network, would static IP's resolve this and if so, should this be applied to the master router or to the wifi access points and repeaters?

Re separating lines, I currently have 4 phone lines with their own routers and none are linked at all. I essentially have 4 networks in the property and they don't communicate. But within each one individually I am having some issues. Each line has around 7 or 8 users connecting via 1, 2 or 3 wifi mini routers. Is the conflict problem coming because of the number of people/devices trying to access the mini routers at the same time?
 
The device giving out IPs via DHCP must have a static (internal) IP; all others should not. If each master router has its own separate network, you shouldn't need to change the IPs.

Most likely, each mini-router is giving out IPs in the same space, so you're getting multiple devices with the same IP. Turn off the excess DHCP servers, then wait a day or two for all the bad leases to expire.

Loads of users could cause drop-outs and slow speeds, but you wouldn't get IP conflicts. Unless you had more than ~250 devices per network, then you might run out of IPs... but it sounds like you top out at 37, so even with five per user you should be fine.
 
Solution