B315 LTE - Use as switch (access point) with Fiber and Back up if fiber goes down

fever2tel

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If you used to have a mobile connection with a Huawei B315 router, and maybe now you have fiber and wish to use the B315 as an access point (i.e. a switch which expands your network), heres a how to guide (after many configuration attempts I thought this may help others):

For my LAN, my fiber router is 192.168.0.1. I wish to connect my B315 to it with a static IP address of 192.168.0.200.

1. Leave DHCP active, dont disable it, i.e.: "WAN -> DHCP"
The IP address here will be the IP address that devices connecting through the B315 router will see as their gateway.
1582194576435.png

2. Next go to "Ethernet -> Ethernet Settings", select static IP (you can use dynamic but I prefer to have my routers IP address static).
IP address are generally assigned ascending order as they are used up and released, I made it 200 so its sufficiently high to not be in use.
Important!! To avoid warnings about "your connection isn't secure": Set the DNS server. I am with afrihost so I set it to their DNS server (169.1.1.1). Use your ISP, if you don't know, then use google's DNS, which is primary: 8.8.8.8 and secondary: 8.8.4.4:
1582194731103.png

3. Thats it! Now devices connecting though your B315 will use the fiber if present. If the fiber goes down (i.e. no power), the B315 (presumably on battery backup) will use its mobile data connection instead. When the fiber connection comes back, the B315 will revert to using the fiber connection again. As you can see there are two different networks, the fiber network (192.168.0.X) and the B315 network (192.168.1.X).

Enjoy!
 
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christoffel2020

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Thanks best instructions on the internet.
I wanted to connect two Huawei routers with same IP addresses (192.168.8.1), so for secondary router I had to change the IP address
So for secondary router I changed IP to 192.168.1.1 and did every thing the same as instructions above.
Worked like charm, I now have a 3rd router connected to the 2nd router.
THANKS THANKS for the instructions
 

SauRoNZA

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Not really a switch but rather a router behind a router in this configuration. (A switch wouldn’t use the WAN port at all, but wouldn’t have any LTE then either).

You’ll have some double NAT problems but it’s probably not the end of the world for a temporary solution. If you plan to use this permanently you are going to have endless kak.

Why not just take the Fiber router out of the equation and use the B315 permanently if you want failover?
 

mattfwb

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Not really a switch but rather a router behind a router in this configuration. (A switch wouldn’t use the WAN port at all, but wouldn’t have any LTE then either).

You’ll have some double NAT problems but it’s probably not the end of the world for a temporary solution. If you plan to use this permanently you are going to have endless kak.

Why not just take the Fiber router out of the equation and use the B315 permanently if you want failover?

Hi SauRoNZA, can you help me understand what the double NAT problems are? I'm looking to try something similar and want to know what I might need to solve along the way.

(I've got raspberry pi that picks up my building's communal WiFi, and using another wifi dongle creates a separate/private wifi network in my flat. The Pi has OpenVPN on it so that all my devices in my flat go through the VPN. And all the network services that are disallowed on the building network like ssh, samba, etc. work on my local network.
The access point is unstable though and frequently drops and I want to create the same scenario as above but with the fibre in the scenario being replaced with a LAN cable coming from my Pi into the B31115.
 

SauRoNZA

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Hi SauRoNZA, can you help me understand what the double NAT problems are? I'm looking to try something similar and want to know what I might need to solve along the way.

(I've got raspberry pi that picks up my building's communal WiFi, and using another wifi dongle creates a separate/private wifi network in my flat. The Pi has OpenVPN on it so that all my devices in my flat go through the VPN. And all the network services that are disallowed on the building network like ssh, samba, etc. work on my local network.
The access point is unstable though and frequently drops and I want to create the same scenario as above but with the fibre in the scenario being replaced with a LAN cable coming from my Pi into the B31115.

If all your traffic is going through the VPN you are bypassing the upstream NAT anyway so not a problem.

It’s usually just an issue for gaming and such more strict services.

As long as you don’t use the WAN port on the B3115 and simply use one of the LAN ports and keep it all in the same range there will be no NAT to worry about as there won’t be any routing happening on the B31115.
 

mattfwb

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If all your traffic is going through the VPN you are bypassing the upstream NAT anyway so not a problem.

It’s usually just an issue for gaming and such more strict services.

As long as you don’t use the WAN port on the B3115 and simply use one of the LAN ports and keep it all in the same range there will be no NAT to worry about as there won’t be any routing happening on the B31115.

Thanks, that's good news on the NAT.

I was going to run the network cable from my Pi to the WAN port on the router <-- but you're saying:
1) don't use the B315 WAN port, use a LAN port <-- easy enough

2) keep it in the same range <-- so:
a) keep it all within 192.168.8.xxx (assuming I use the B315 default range)?
b) And then set "default gateway" as the (static) IP address of the Pi's ethernet?
c) doesn't really matter where the DHCP sits then....? B315 could for example hand out any dynamic IPs from 192.168.8.100-200..... could I turn DHCP off on the B315 and use DHCP on the Pi instead, without it falling over or causing issues with this setup?

Thanks for your help and time, its very much appreciated.
 

SauRoNZA

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Thanks, that's good news on the NAT.

I was going to run the network cable from my Pi to the WAN port on the router 1) don't use the B315 WAN port, use a LAN port
2) keep it in the same range a) keep it all within 192.168.8.xxx (assuming I use the B315 default range)?
b) And then set "default gateway" as the (static) IP address of the Pi's ethernet?
c) doesn't really matter where the DHCP sits then....? B315 could for example hand out any dynamic IPs from 192.168.8.100-200..... could I turn DHCP off on the B315 and use DHCP on the Pi instead, without it falling over or causing issues with this setup?

Thanks for your help and time, its very much appreciated.

Correct.

Choose where you want the DHCP server so you have only running and then an IP range associated with it, it can be the Pi or the B315.

Using the LAN ports it’s just a gloried switch and doesn’t do any routing and therefore no NAT but can still offer wireless etc.

You wouldn’t even need to tell it what the gateway was if it wasn’t the DHCP server as it won’t be doing any traffic from itself and only switching traffic.

Personally I’d do it all on the Pi and treat the B315 as a dumb switch.

In reality you don’t even need to give it an IP, that’s only there for easy management.
 

JJinsa

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Correct.

Choose where you want the DHCP server so you have only running and then an IP range associated with it, it can be the Pi or the B315.

Using the LAN ports it’s just a gloried switch and doesn’t do any routing and therefore no NAT but can still offer wireless etc.

You wouldn’t even need to tell it what the gateway was if it wasn’t the DHCP server as it won’t be doing any traffic from itself and only switching traffic.

Personally I’d do it all on the Pi and treat the B315 as a dumb switch.

In reality you don’t even need to give it an IP, that’s only there for easy management.
Hi everyone. Came across this thread and in need of similar help.
I have what is called “air” fibre. Basically last mile is wireless point to point.
The main router is connected to the antenna, and apparently the antenna according to ISP works like a router as well.
I then want to use my b315 as an access point further away in the house. So I connected it to the first router in the house, via Ethernet into the WAN port of the b315. I then did all the settings and internet was working etc. But on my Xbox it was having double NAT issues. ISP is stuck on how to help as am I. Connecting the Ethernet into the LAN port instead of WAN loses the internet connection.
 

SauRoNZA

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Hi everyone. Came across this thread and in need of similar help.
I have what is called “air” fibre. Basically last mile is wireless point to point.
The main router is connected to the antenna, and apparently the antenna according to ISP works like a router as well.
I then want to use my b315 as an access point further away in the house. So I connected it to the first router in the house, via Ethernet into the WAN port of the b315. I then did all the settings and internet was working etc. But on my Xbox it was having double NAT issues. ISP is stuck on how to help as am I. Connecting the Ethernet into the LAN port instead of WAN loses the internet connection.

Give the B315 an IP in the same range you get when plugged directly into the main router. Probably safest to use the very next IP after the router.

So if it’s 192.168.0.1 then make the B315 192.168.0.2.

Not disable the DHCP server on the B315.

Then plug into one of the LAN ports on the B315 and you should be good to go.
 

JJinsa

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Give the B315 an IP in the same range you get when plugged directly into the main router. Probably safest to use the very next IP after the router.

So if it’s 192.168.0.1 then make the B315 192.168.0.2.

Not disable the DHCP server on the B315.

Then plug into one of the LAN ports on the B315 and you should be good to go.
Thanks for the response. The IP on router 1 is 10.0.0.2, and I currently have IP on router B as 10.0.0.251. What do you suggest I make it?
Do you mean I must disable DHCP or must not? Think you had a typo there? It is currently disabled.
 

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SauRoNZA

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Thanks for the response. The IP on router 1 is 10.0.0.2, and I currently have IP on router B as 10.0.0.251. What do you suggest I make it?
Do you mean I must disable DHCP or must not? Think you had a typo there? It is currently disabled.

DHCP SERVER should be Disabled. Your upstream Router is doing that.

Those settings seem relevant to the WAN port rather than the router itself. And the DHCP there is for being a client not a server.

But 10.0.0.251 might be inside the DHCP scope of the main router so play it safe and make it 10.0.0.1 which we know will will be open for sure.

Then connect to the main router on one of the LAN ports. Don’t even use the WAN port as there is what is causing your double NAT.

When connected to the B315 whether physically or wirelessly you should then still get an IP from the main router in the 10.0.0.0 range and be able to ping both 10.0.0.1 and 10.0.02.

******

Look at the first picture in this thread. Those are the relevant settings for setting the IP and turning off the DHCP server.

Ignore the text however. I’m only referring to the image for reference.

The information was bad and hence my objections about it in my first post causing exactly the double NAT problem you are experiencing now.
 

JJinsa

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DHCP SERVER should be Disabled. Your upstream Router is doing that.

Those settings seem relevant to the WAN port rather than the router itself. And the DHCP there is for being a client not a server.

But 10.0.0.251 might be inside the DHCP scope of the main router so play it safe and make it 10.0.0.1 which we know will will be open for sure.

Then connect to the main router on one of the LAN ports. Don’t even use the WAN port as there is what is causing your double NAT.

When connected to the B315 whether physically or wirelessly you should then still get an IP from the main router in the 10.0.0.0 range and be able to ping both 10.0.0.1 and 10.0.02.

******

Look at the first picture in this thread. Those are the relevant settings for setting the IP and turning off the DHCP server.

Ignore the text however. I’m only referring to the image for reference.

The information was bad and hence my objections about it in my first post causing exactly the double NAT problem you are experiencing now.
I’m confused. It says in that first picture:
192.168.8.1
DHCP server - enable
Must I leave it as enabled then?
I’m not in any way experienced at this so excuse my questions.
 

JJinsa

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DHCP SERVER should be Disabled. Your upstream Router is doing that.

Those settings seem relevant to the WAN port rather than the router itself. And the DHCP there is for being a client not a server.

But 10.0.0.251 might be inside the DHCP scope of the main router so play it safe and make it 10.0.0.1 which we know will will be open for sure.

Then connect to the main router on one of the LAN ports. Don’t even use the WAN port as there is what is causing your double NAT.

When connected to the B315 whether physically or wirelessly you should then still get an IP from the main router in the 10.0.0.0 range and be able to ping both 10.0.0.1 and 10.0.02.

******

Look at the first picture in this thread. Those are the relevant settings for setting the IP and turning off the DHCP server.

Ignore the text however. I’m only referring to the image for reference.

The information was bad and hence my objections about it in my first post causing exactly the double NAT problem you are experiencing now.
I have set exactly as per first pic of thread, and also enabled port forwarding. Getting open NAT now. Thank goodness.
Thank you!
 

SauRoNZA

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I’m confused. It says in that first picture:
192.168.8.1
DHCP server - enable
Must I leave it as enabled then?
I’m not in any way experienced at this so excuse my questions.

Read my instructions again and read theM carefully.

DISABLE the DHCP Server and don’t follow those instructions just look at the picture for reference.
 

SauRoNZA

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I have set exactly as per first pic of thread, and also enabled port forwarding. Getting open NAT now. Thank goodness.
Thank you!

You are still over complicating and slowing down your network even if it says it works.

You won’t need port forwarding as you won’t have a second NAT if you do it the way I explained.

Now you’ve engineered a whole second network that will only work with one device for no good reason at all.

You don’t want a second network or a second NAT and no port forwarding.

You just want a glorified access point and to let your main router do all the work.
 
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