Connecting A Linksys E2500 To An Existing Modem/Router - Questions Please

[Tyler17]

As I just upgraded my router this week, I was thinking of giving my old Linksys E2500 (running Advanced Tomato) to my brother since his existing wireless router doesn’t seem to provide a very stable wireless signal in his apartment. There might be signal interference issues because his router channel is set to auto and he is on a crowded channel, or some other reason, but what the exact issue is I'm am not sure.

Anyway, I was wondering if I could just attach my E2500 to his existing modem/router with a LAN cable and have the E2500 receive the internet connection from his existing router so that I can turn the E2500 into a second wireless internet connection for him in his apartment?

Also, is it possible to do this without putting his existing router into bridge mode?

Assuming the above would work, what sort of configuration would I need to make to Tomato on Basic Settings > Network > WAN Settings on the E2500?

The reason it would be helpful if I can set it up as per above (rather than setting things up as a bridge or another way) is he lives far away from me and I will be visiting his apartment for just 1 day in the near future. So I would like to avoid doing a lot of reconfiguration to his existing router since I won’t have much time there. It would be great if I could just sort of plug and play the E2500 into his existing router and get the E2500 running with the internet quickly.

I also don’t know the username and password for his existing router, and I don’t think he does either. Plus I don’t know if his router is set up for wireless admin access. I will only be traveling with a tablet computer when I visit him so I would have no way to hardwire a desktop computer to his existing router (assuming it isn’t set up for wireless admin access) to be able to configure anything anyway.

If I know how to pre-configure my E2500 then I could get it setup and test it with my own existing router first under the above scenario and then have it ready to just plug into his router when I get there.

Thank you for any input you may be able to offer on this please.

 

[Ralston18]

This is the "show stopper":

"
I also don’t know the username and password for his existing router, and I don’t think he does either."

To do anything at all along the lines you envision will need cooperation and assistance from whomever manages the router and its specific network.

E.g. assigning and reserving a static IP address per the E2500's MAC. That IP address will need to be outside of the host router's allotted DHCP IP address range as well.

If it is his router and he has forgotten the admin name and password then a factory reset will need to be done and you will be faced with a network do-over. Which, at the time, would permit you to incorporate the E2500.

 

[BFG-9000]

Actually it doesn't matter even if the AP's IP address is on a different subnet, provided:
Your brother does not care to ever configure the AP himself (well he could if he set a fixed IPv4 address on the computer to do so)
Your brother does not care to print over the AP's USB port
Your brother does not care to access any shared files on a USB stick plugged into the AP's USB port

The main router does not need to be in bridge mode; DHCP will hand out addresses to clients attached to the AP just as if it were a switch plugged into an ethernet port and the router does not know or care that wifi exists downstream.

However it's still best to get from your brother at least the IP address of his current router before you go over there. He does not need to log into the router to get this and even the IP address assigned to his computer is usually a big clue to what it is (generally it will be the same except the last number will be 1. Usual defaults are 192.168.0.1 or 192.168.1.1). This allows the above to work and to specify a default gateway on the AP.

You'll need to configure the AP before you bring it over. You mainly need to untick the DHCP setting under "LAN", and to set an IP address that's different than the router's but preferably on the same subnet (like 192.168.1.2). Don't worry about it not being fixed on the router too as rebooting everything on the network will give the selected address to the AP. Default Gateway and Static DNS should both be set to the router's address (like 192.168.1.1). The last thing I like to do is change under "WAN/Internet" Type to Disabled and tick Bridge WAN Port to Primary LAN (this makes the WAN port into a 5th LAN port so you don't need to be careful about which port you are using).

If you can, find out from your brother which channel(s) his present Wifi is on and select a different one (he can use a phone with a free utility like Wifi Analyzer or a PC with InSSIDer). E2500 is a dual-band router so set up 5GHz too even if he's not presently using it. Use the same SSID and security WPA2-PSK (AES) key he presently uses so he doesn't have to do anything different for his devices to roam onto your AP.

With this, you should be able to simply bring it over and plug it into his network.

 

[Tyler17]

Thank you both for your good feedback and for the sake of argument I will assume that the IP on his router is set to 192.168.1.1 and that his IP range is something like 192.168.1.2 - 192.168.1.51. I am sure it was setup either by the factory or his ISP and never changed to anything custom.

Also, my brother just uses his wi-fi with his smartphone and a simple tablet at the moment I think (his laptop died recently) and at most would be connecting a laptop to it in the future when he gets a new one so he could send email and surf the web. No printing I am sure. Also, not even sure if the router he is using now has a USB port. The E2500 doesn't and he wouldn't be getting into any network sharing stuff. So none of that is a worry I don't think.

So if I untick DHCP on the E2500 and set the IP to 192.168.1.5 I think I should be alright.

I think I am now going to set it up this way (per above) and disable WAN, tick Bridge WAN Port to Primary LAN, and test it by connecting it to my existing router and see if I at least configured it correctly. If I run into any problems I will let you know. Thanks again.

 

[Tyler17]

Yup, perfect, the above works with the E2500 on my existing router at home. I changed the settings on the E2500 as per the above and connected it via a LAN cable to my existing router (on the E2500 I plugged the LAN cable into the yellow colored Internet port and not one of the 4 blue colored LAN ports), and then I connected to the E2500 on the 5 GHz channel with my iPad and was able to connect to the internet. Easy.

The only unknown here is his own IP and IP range. As long as I set the static IP on the E2500 to something aside from 192.168.0.1 or 192.168.1.1, then I am probably safe, even if it isn't within his subnet, correct?

I can also do a test now by setting the E2500 with an IP outside of the IP range on my existing router and connect it and see if it still works, right?

 

[BFG-9000]

Yep, if it's on the wrong subnet he just won't be able to access the AP's configuration page normally. It's best to specify a Default Gateway though instead of 0.0.0.0 (which means "undefined") so that any out of subnet requests get directed to the router for sure.

If your brother could at least tell you the brand of his router you would at least be able to find what that brand uses as a default IP.

The AP's IP address can actually lie within the router's IP range without issue as rebooting all devices will quickly clear up any duplicate if only one of them is fixed, or you could specify something like 192.168.1.254 to be within the subnet but outside the routable range.

 

[Tyler17]

Yep, if it's on the wrong subnet he just won't be able to access the AP's configuration page normally. It's best to specify a Default Gateway though instead of 0.0.0.0 (which means "undefined") so that any out of subnet requests get directed to the router for sure.

If your brother could at least tell you the brand of his router you would at least be able to find what that brand uses as a default IP.

The AP's IP address can actually lie within the router's IP range without issue as rebooting all devices will quickly clear up any duplicate if only one of them is fixed, or you could specify something like 192.168.1.254 to be within the subnet but outside the routable range.

I don't foresee him ever wanting to log into the router's admin page, so its not a worry. He doesn't know anything about routers or networking, so it is way above his pay grade.

Where you say Default Gateway though, I don't see that setting in Tomato. Do you mean the router's IP address?

I have asked him for the brand and model of his router since Friday and he should send that to me soon. I had thought the same in that with that information I could at least check what the manufacturer's default IP is.

Anyway, 192.168.1.254 is a good idea on the IP instead of 192.168.1.5 just to be safer. But what would happen for example if the IP range on his router was only set from say 192.168.1.2 to 192.168.1.51?

Thanks again...

 

[BFG-9000]

I'm not sure about Advanced Tomato, but in regular Tomato both Default Gateway and Static DNS settings are right under IP range on the Basic Network page under LAN.

Technically you are supposed to put anything with a fixed IP address on the same subnet but outside the IP range of the router, so DHCP doesn't hand out that address to something else while the fixed device isn't powered on and you get duplicate devices with the same address. In this case though the AP is always powered on so it is unlikely to be a problem.

 

[USAFRet]

In this case though the AP is always powered on so it is unlikely to be a problem.

Until a nearby lightning strike bleeps the house power for a moment.

 

[Tyler17]

I'm not sure about Advanced Tomato, but in regular Tomato both Default Gateway and Static DNS settings are right under IP range on the Basic Network page under LAN.

Technically you are supposed to put anything with a fixed IP address on the same subnet but outside the IP range of the router, so DHCP doesn't hand out that address to something else while the fixed device isn't powered on and you get duplicate devices with the same address. In this case though the AP is always powered on so it is unlikely to be a problem.

Thank you. linked below is a screenshot of the LAN settings in Advanced Tomato.

https://s1.postimg.org/jr8gndp4f/image.jpg

 

[BFG-9000]

Huh, I just fired up my spare router with Advanced Tomato v132 on it and the settings are there right between the Add+ button and DNSSEC. Perhaps it was later removed as they probably aren't strictly necessary when DHCP is disabled (it's supposed to allow things like the router time to be set automatically, but when set as an AP none of those things work anyway).

That should make things simpler for you as it means everything should just work even if you guess 50/50 and get the wrong subnet. So just 192.168.0.254 or 192.168.1.254 it is!

I try not to use the newer multi-WAN Tomato as I find them buggy compared to the rock solid single-WAN versions on MIPs based routers (my uptime on v132 is presently 21 months). If I wanted buggy I'd use DD-WRT or an ARM router!

 

[Tyler17]

Huh, I just fired up my spare router with Advanced Tomato v132 on it and the settings are there right between the Add+ button and DNSSEC. Perhaps it was later removed as they probably aren't strictly necessary when DHCP is disabled (it's supposed to allow things like the router time to be set automatically, but when set as an AP none of those things work anyway).

That should make things simpler for you as it means everything should just work even if you guess 50/50 and get the wrong subnet. So just 192.168.0.254 or 192.168.1.254 it is!

I try not to use the newer multi-WAN Tomato as I find them buggy compared to the rock solid single-WAN versions on MIPs based routers (my uptime on v132 is presently 21 months). If I wanted buggy I'd use DD-WRT or an ARM router!

So sorry, my bad. That screenshot I took from my other router, which, under WAN, is running in PPPoE. When it is in PPPoE you get those settings under LAN I screen shotted in my last post. Here is a screen shot from the correct LAN settings from my E2500, which is the router we are discussing here:

https://s1.postimg.org/87sso4k0v/image.jpg

I am still very much a networking noob though (it's obvious too I guess) and a lot of what I am doing here is just filling in boxes without always fully understanding what things mean. So I am again sorry for any errors I am making.

Anyway, I have had no real problems with Advanced Tomato, except for the fact that I just wasted 2 hours with this E2500 that started acting strangely for the first time after using it without any problem for over a year.

So a problem has now arisen with the E2500 and may be due to the fact that I have nothing listed for Default Gateway, but I am not sure?

What first started happening today is that I could no longer access the admin log-in page wirelessly after powering up the router (I had powered it off for the last 24-36 hours as I wasn't using it for anything except these tests we have been discussing). And this new problem is strange because I was able to access it wirelessly without any problem for the past few days. Then I plugged it into my desktop and same thing. Nothing would come up with the IP I had assigned it, which was 192.168.3.1 at the time. Finally I held in the reset button for 10 seconds and got it to come back up under 192.168.1.1.

After that it would continue to crash over and over again while changing settings via the admin login. Finally I flashed it with Advanced Tomato again and loaded all my settings back in manually to start fresh. Then it seemed stable again, but every time I log out now from the admin page it goes back to having no IP. The only way to get the IP to reappear (so that I can log back in) is by power cycling it once. After I do that I am able to pull up the admin panel again in the browser under the IP assigned, which I now set to 192.168.1.254 as you suggested.

So now it is set exactly as you see it in the screen shot above. But why it keeps losing the IP address now every time I log out I just don't know. This is a first time for all these odd problems. So not sure if suddenly the hardware is starting to fail for some reason or if this is related to the fact I don't have a default gateway set. Should I be setting the default gateway or just leave it as is?

But again, I don't think the missing default gateway is the problem. I had been logging in and logging out, powering on powering off for the last few days with LAN disabled, IP set to 192.168.3.1, with no default gateway set, but with no problems or loss of IP until now.

 

[Tyler17]

At this point I think the router is either DOA, FUBAR, or BRICKED. I had flashed the firmware again, and then, before putting in all my settings, I decided to do a 30/30/30 to make sure the Nvram was cleared out.

After that I was able to bring it up once and change the IP to 192.168.3.1 - I gave up on 192.168.1.254 since I had good luck with 192.168.3.1 before. But after I changed the IP I couldn't pull it up again at all. I tried resetting it again with the reset button for 10 seconds. Nothing. Then I did another 30/30/30 and still nothing. The router just seems to not be able to reset itself back to 192.168.1.1 and appears to just be stuck with no IP. I guess it is bricked???

 

[BFG-9000]

I was going to tell you there are some settings stored in NVRAM that aren't erased with the reset button. So if you upgrade from OEM or single-WAN you're supposed to go into Administration: Configuration and select Restore Default Configuration: Erase all data in NVRAM memory (thorough).

The E2500 board is ridiculously sparse and it has only two caps by the power jack. If you open it up (or try to peek through the vents with a flashlight) and see bulging tops then you have found your problem

If it's just bricked from a bad flash, the firmware is like the OS but the CFE is like the BIOS and may still be good, in which case you just need to reflash the OS. By FTP because you no longer have an OS with a nice GUI.

To see if the CFE is still booting the device, set your IPv4 address to something fixed in the default subnet like 192.168.1.4 and direct wire to the malfunctioning router (ie, not to your network)
Open a command prompt and type PING -t 192.168.1.1 and press enter to get a stream of responses.
If the reply has TTL of 100 (even momentarily after a reboot) the CFE is still alive. If so:

run tftp2.exe
In the field “Server” enter the default IP of the router, which is 192.168.1.1.
In the field “Password” enter the default password of the router which is "admin" for Tomato (no username is needed)
In the field “File” browse and locate the firmware file. I suggest v132
Unplug the router's power for 10 seconds then turn it back on.
While the router is still in the boot process (ie. Power light is still 'amber') click on 'Upgrade' and wait for the process to be completed.
Once the process is complete the power light will turn stable green and then the only thing required is to erase the NVRAM then reconfigure the router from scratch. Congratulations, you have resurrected a $5 router!

Well at least locally here all of the used computer stores sell N routers for $5 with a 30-day warranty. Seems like everyone wants AC routers now.

 

[Tyler17]

Thank you, I had already tried something similar yesterday with Tftp. I had an older version of the Tftp program and tried flashing it with the stock firmware. The result I got was "Unable to get response from the server". I just tried it again using Tftp2 and the older Tomato firmware version you mentioned, but same issue, "Unable to get response from the server". I just tried pinging it again as well, but nada unfortunately. If I go to Network and Sharing center, click on Ethernet, and in the Ethernet Status box that comes up I click Details, IPv4 is blank for Default Gateway, DNS Server, and WINS Server. It just has no IP and I have done a troubleshoot many times to try to reset the adapter and it always fails saying "Ethernet does not have a valid IP configuration". So maybe it is DOA as it doesn't seem able to assign an IP anymore to the router? I also opened it up and looked at the caps and they look fine to me although I am not 100% sure I would be able to tell if they are bulging or not, but they do look normal as per your sample photo.

Sometimes if I hold in the reset button and reboot a few times I can get a 192.168.1.1 to appear for the IPv4 for Default Gateway and DNS Server, but if I try to flash the firmware or do anything then immediately the IP disappears again and the flashing still fails.

I also tried a couple of different LAN cables to be sure it wasn't a cable issue, but still getting no love from this bad boy. I think maybe I have run out of tricks, but it does seem a bit odd that the hardware would suddenly die from flashing the firmware a few times.

I paid a bit more, $25 for it as a refurb last year on Amazon

 

[Tyler17]

I have now gotten a USB to ethernet adapter and was able to connect the E2500 to my laptop. It lives! It took a few minutes for it to get assigned the 192.168.1.1 IP address by my laptop (it was back to 192.168.1.1 because I had done a reset on it) and then I was able to get back to the Tomato admin interface via the browser and reconfigure the router to 192.168.3.1 and made all the other wireless settings needed. I am glad I didn’t just bin the thing.

When I plug it back into the desktop as before though it still comes up without an IP for some reason. I don’t know why but the router and my desktop PC have decided they don’t like each other anymore. That is OK. Not so important. The router is alive and correctly configured now the way I want it.

Now I can focus again on trying to get it setup to bring over to my brother’s house so I can just plug it into his existing router and give him a better wireless access point to connect to his internet.

So I am back to testing it with my existing router to make sure it is all going to work when I get it over to my brother’s place. So I plugged a LAN cable from one of the 4 LAN ports on my existing router that has internet access into one of the LAN ports on the E2500. Then on the E2500 Tomato settings I have this for Network:

Wan Settings > Type > Disabled

LAN > IP Address 192.168.3.1 > DHCP Disabled

All Is working fine. I can access the E2500 wirelessly and can use it to surf the internet using the internet connection from my existing router. All is well.

The only problem is I don’t know my brother’s default gateway and I am pretty sure I won’t be able to get into his router to check it since I won’t have a computer with me when I go to his place and he doesn’t have one either at the moment. He just uses internet wirelessly with his smartphone and tablet. I will have my iPhone and iPad with me, but unless his router is set up for wireless admin access then it will be useless. And the router was installed by his ISP when he connected service. So I don’t think he even knows what his router’s admin username and password are. The only thing he knows is the Shared Key for his router so he can use WiFi.

So let’s just assume I won’t be able to check his default gateway. My default gateway on my existing router though is 192.168.2.1 with a DHCP range of 192.168.2.1 through 192.168.2.51. And when I connect the E2500 to it with an IP of 192.168.3.1 on the e2500 it works fine even though the IP is outside the DHCP range. So can I assume it will work the same with his router if the E2500’s IP remains outside of his DHCP range?

 

[BFG-9000]

Should work fine, just won't be able to access the E2500's configuration page to change it without setting the computer to a static IPv4 address in the 192.168.3 subnet. Without a computer you can set the iPhone or iPad to a static IP instead.

Surprisingly, a lot of ISP-provided modem/router devices have a specific random user and password printed right on it (instead of the generic one like "admin" common on retail routers), and wireless admin access must be turned on by default because so many people have no wired devices nowadays.