4g Failover on sg135

Martin, take a look at this thread.

Cheers- Bob

Thanks Bob,

I had a chat to Sophos and they came up with this:

Seems to work well.

What do you think?

The Dell XPS subnet represents the Hotel Back Office.

The Internal Network represents the Guest Network.

So when the External Wan goes down, the Dell XPS retains internet access via the 4G connection.

Well, if you read the link I posted above and if I understand what you want to happen, I would not do it that way.

I would put both interfaces in 'Active' unless the 4g connection is not a fixed, monthly fee.

I would masq 'Internal (Network) -> Uplink Interfaces' and 'Dell XPS (Network) -> External (WAN)'.

I would make the first Multipath rule 'Any -> Any -> Any bound to External', the second would be 'Internal (Network) -> Any -> Any bound to 4g MF821' and the final 'Any -> Any -> Any bound to External with 'Skip rule on interface error' unchecked'.

Cheers - Bob

Well, if you read the link I posted above and if I understand what you want to happen, I would not do it that way.

I would put both interfaces in 'Active' unless the 4g connection is not a fixed, monthly fee.

I would masq 'Internal (Network) -> Uplink Interfaces' and 'Dell XPS (Network) -> External (WAN)'.

I would make the first Multipath rule 'Any -> Any -> Any bound to External', the second would be 'Internal (Network) -> Any -> Any bound to 4g MF821' and the final 'Any -> Any -> Any bound to External with 'Skip rule on interface error' unchecked'.

Cheers - Bob

Thanks Bob, I really do appreciate all the help you provide to me :)

I'm not that fussed about instant failover, but if it's available without incurring huge data costs then I'll look at it.

I have 2 options with Telstra, the 4G service I use:

A) I have a prepaid usb modem that has about 20GB in it. However this has the private IP address problem as listed in my OP.

This is my own modem, so I'd only charge the Client $10/GB for usage.

B) A Business 4G service which is monthly, starting at $40 per month with 5GB included, overage is at $10/GB.

So I'd prefer A) as would the client, but I think the private IP address would kill it.

So, assuming B) is the way to go, would the multi-path still be the best way?

I'd try it with both in Active and see what the usage is when the 4g connection's not actively being used.  You can probably tell from looking at the charts in 'Network Usage' and on the 'Bandwidth Usage' tab.  Please let us know what you find.

Cheers - Bob

Thanks again Bob,

Another issue we have is that the primary internet is very intermittent, ie it will be active but incredibly slow.

This means the 4G failover doesn't kick in.

Is there a way to say if the speed drops below a certain amount, say 1Mbps, the 4G kicks in?

No way, Martin.  It seems like a business connection would have an SLA and that the hotel could lean on them to get their line fixed.

Cheers - Bob

Thanks Bob,

Sadly in Australia SLAs don't mean much when dealing with Telstra/NBN, at the moment they just blame each other.

In any event, even with SLAs they only refund a pittance if the line goes down for x%.

They don't actually fix the problem.

That might tempt me to switch to Vodafone. ;-)

If the outages are longer, you could show someone at the site how to disable/enable the Interface in WebAdmin.

If you're a bit of a Linux wizard, you could craft a way to have someone run enable/disable scripts from their PC.  At the command line as root, get the REF_ of a PPPOE interface named External with cc get_object_by_name interface pppoe 'External' |grep \'ref\' - let's say you learn that it's REF_IntPpeExternal.  Disable the interface with cc change_object REF_IntPpeExternal status 0 and enable with the same command with 1 instead of 0.

Good luck, mate!

Cheers - Bob

Hi Bob,

Sorry it's taken so long to respond, but I haven't been able to reply or create forum posts because Ublock Origin is blocking parts of the Forum :(

Back to 4G Failover :)

After working with Sophos Support, they came up with this:

"We have kept both the ISPs in the Active state in Uplink Balancing.
MASQ Config :

We have created three Mutipath rules as below,
1
Source : Martin Network
Service : Any
Destination : ANY
Interface : External WAN
Tick : Skip rule on interface error
2
·         

Source : Martin Network
Service : Any
Destination : ANY
Interface : External: 4G
Tick : Skip rule on interface error
3
·         

Source : Home Network
Service : Any
Destination : ANY
Interface : External WAN
Untick : Skip rule on interface error
We have tested keeping the WAN off and its working as expected."

Which all seemed to work except the 4G Service would go down, and not recover, after a day or two.

Sophos have suggested the following:

"Would it be possible to disable the Automatic Monitoring and add the Google DNS Address 8.8.8.8 as a monitoring host and check if you encounter the same issue?"

Which I haven't been able to test, I'll do so this weekend.

That probably won't help, but it's worth a try.

FWIW, I always prefer using Multipathing and having both interfaces in 'Active' unless paying by the megabyte-transferred for the backup connection.

Cheers - Bob