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Making my system more robust

I am using a remote cable modem to feed an NBE 5AC-gen2 links by radio to another NBE 5AC-Gen2.  It then links to a PBE 5AC-ISO by wire and then to a PBE 5AC-ISO by radio.  It all works great delivering 400+ Mbps throughput.

 

The problem is that the link is that the RF links traverse a mountain and are subject to high winds.

 

I would like to access the link from both ends for troubleshooting & maintenance purposes.  I can find the public IP address of the cablemodem connection but what configuration steps do I use on the NBE 5AC-Gen2 to access it from the internet/modem side of the link?  What tools do I use to access the public IP address and through it to the private IP address of the NBE?

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Re: Making my system more robust

What's missing in your description is any router; my hunch

is the router function is embedded in the ISP's modem.

 

If so, it may be difficult to access anything in your local

network easily, because you may not be able to modify

forwarding rules in your modem/router. If that's the case,

you may be able to put the modem in 'bridge mode' and

use your own router. Better yet: you may be able to buy

your own modem as well and save the monthly fee.

 

You typicaly pay the value of that modem every single year.    Dave


> HQ in Seacoast region New Hampshire U.S.A.
> Ubiquiti Certified Trainer [UCT] for:
     UBWA [AirMax] / UEWA [UniFi] / UBRSS [routers]
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Re: Making my system more robust

Thanks for the quick reply, Dave.

Indeed there is no router! The cable modem is just a cable modem.

My objective is to be able to reach the link from the internet side or from the remote side. When all is well, access from the one end tells all. When the weather breaks something, I need access from both ends to isolate the fault.

Do I need to setup the system with two routers?

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Re: Making my system more robust

[ Edited ]

Now I'm confused! There either must be a router function

or your network is entirely on the public Internet. Are you

completely sure the cable modem doesn't contain a router?

 

If you mean that you are transporting the 'raw' output from

a cable modem to another site, that means that the radios

are all on the public Internet--not on your LAN. You don't

have the isolation a router would provide. But this doesn't

seem to make sense: don't you have some end device such

as a computer? You wouldn't typically have that setup for use

directly on the Internet--that would be incredibly unsafe.

 

Perhaps if you describe everything on your network it would

help; I'm convinced there's a router.   Dave

 


> HQ in Seacoast region New Hampshire U.S.A.
> Ubiquiti Certified Trainer [UCT] for:
     UBWA [AirMax] / UEWA [UniFi] / UBRSS [routers]
UBNT.NH@gmail.com
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Re: Making my system more robust

I'm describing the system as it is: cable modem<-->NBE RF NBE<-->PBE RF PBE<-->router. The cable modem does not have an embedded router. It is a modem only but it does have an embedded web management page.

When all is working I can reach all the equipment from the router end of the link.

When weather disrupts things, I'd like to access the portions of the link that are intact from the internet (cable modem) side.

I can find the (public) IP of the modem but how can I access devices behind it? Do I have to deploy a server and router behind the modem just to gain access to the modem-side of the link or can the radios act as servers?
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Re: Making my system more robust

I'm not sure why you keep drawing strict lines around your

question. It turns out there is a router--at the far end of this

set of links for your end-point devices. I think it's your way

of trying to force the discussion in a single direction.

 

I sense you know the 'regular' solution to this: place your

router at the modem and transport a LAN subnet through

the links. If the radios have valid IP addresses in the LAN

subnet, they will be accessible--as you would expect.

 

If you won't do it that way, you can connect to your link

in front of the router--you could add a switch there, for

easy access without breaking the connection. With a PC

set to the subnet of the radios, you can access them there.

 

Or, I suppose you could find a way to forward traffic from

specific LAN subnets to the WAN port, to accomplish the

same goal; I don't know how to do that.  Dave

 

 


> HQ in Seacoast region New Hampshire U.S.A.
> Ubiquiti Certified Trainer [UCT] for:
     UBWA [AirMax] / UEWA [UniFi] / UBRSS [routers]
UBNT.NH@gmail.com
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Re: Making my system more robust

Dave,
The modem I use is a Motorola DM7420. If you examine its specifications you will see that it does NOT have an embedded router.

"I'm not sure why you keep drawing strict lines around your
question. "

I'm perhaps a bit over-sensitive as to why you might impugn my motives in asking if there is know-how to be leveraged solving a common reliability problem:; to wit: a wire has a discontinuity somewhere in its length. Find it given you only have access to the terminal ends of the wire.

Placing the problem in the context of my RF link, I can access the internet end of the link and I can access the remote end of the link. The fault lies in between the two. Locate the fault.

Since we don't know when or where the fault will occur, the only scheme I can device is to deploy two routers. The 'main' router runs the subnet when connections are intact. The 'backup' router monitors connectivity by periodically pinging the main router. When a break is detected by failure of the ping, the backup router is enabled allowing a local server (co-resident with the modem) to access network nodes reachable from the modem end.

If there is an easier solution, I'd love to learn about it.
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Re: Making my system more robust

[ Edited ]

'Impugn' is a tough word; what I'm pointing to is your sterilized

syllogism: 'to wit:...given you only have acess to the terminal

ends....  In fact, you do have access beyond the ends, and your

new proposed strategy ignores your 'to wit...'.

 

I repeated my question about the modem/router because it wasn't

clear whether a WAN or LAN is transported across the radio links.

That's a critical factor to a strategy, as I tried to point out. If you

simply put your [one] network router at the modem, you have full

access to the radios [on the LAN] and can ping them at will--from

either end. For example, a failed ping from that router to the last

link radio [servicing the client devices] could enable a server.

 

[You don't need a second router if all you need is a ping target.]

 

I already suggested that, but you seemed to reject it. I don't

have much more to offer.   Dave

 


> HQ in Seacoast region New Hampshire U.S.A.
> Ubiquiti Certified Trainer [UCT] for:
     UBWA [AirMax] / UEWA [UniFi] / UBRSS [routers]
UBNT.NH@gmail.com
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Registered: ‎09-28-2017
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Re: Making my system more robust

A fact that I haven't shared is that I have approximately 40 nodes at the remote site. To use these nodes (printers, NAS, thermostats, TVs and such via wired and WiFi) I need a router a that site even when the link is down, don't I?

Therefore, the simplest solution is probably to get an integrated modem & router, to let it handle the routing chores (even for nodes at the remote site) and to manually cut in the 'backup' at the remote site when the link is down.

Agree?

How then can I access the subnet behind the modem/router when the link is down? Port forwarding to a radio's server?
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Re: Making my system more robust

[ Edited ]

Don't you get my frustration at the 'facts you haven't shared'?

We've wasted time discussing strategies that can't work.

 

Clearly, link checks and failback have to be at the the 'modem end',

and pings to the destination are an obvious method.. There can be

some kind of device that does these by pinging the destination via

the radio link and doing failback if a response is lost. This radio link

is transparent and can be multi-homed if necessary. This is a sort

of 'dead-man timer' functiion, andi I don't know of a routher that has

it. If not, that means a custom application and I/O.

 

If a router isn't used for the 'dead-man', it might as well be at the

destination, so there is no need for a backup for router loss. If it

turns out you find a router that does that job at the modem end,

you could conceivably use a backup router at the destination.

But this has some real problems: if the router provides DHCP

to the LAN [usually the case, a second router in its place won't

have a record of the prior leases. If the DHCP service checks

for duplicates, that might not be a problem. Because the

backup does no routing, that doesn't need to be considered.   Dave

 

 


> HQ in Seacoast region New Hampshire U.S.A.
> Ubiquiti Certified Trainer [UCT] for:
     UBWA [AirMax] / UEWA [UniFi] / UBRSS [routers]
UBNT.NH@gmail.com
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Re: Making my system more robust


@tbbrightman wrote:
A fact that I haven't shared is that I have approximately 40 nodes at the remote site. To use these nodes (printers, NAS, thermostats, TVs and such via wired and WiFi) I need a router a that site even when the link is down, don't I?

 The fact is that you need one, especialy if this is not just a straight wireless bridge.

 


@tbbrightman wrote:
Therefore, the simplest solution is probably to get an integrated modem & router, to let it handle the routing chores (even for nodes at the remote site) and to manually cut in the 'backup' at the remote site when the link is down.

Agree?

 Since you already have the modem(cable) you just need a router.

 


@tbbrightman wrote:
How then can I access the subnet behind the modem/router when the link is down? Port forwarding to a radio's server?

 More that one way to skin a cat.

 

Access the router from WAN (ssh, VPN, IPsec, etc )and from there access all devices from there OR use something like TeamVieawer alike to login into a device behind the router and from there make your way to other.

 

Regards, 

Do not expect me to reply to this post, I'm not sure that I will be able to find it, thank's to ....

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