Hybrid Connect, network switch, separate DHCP server

[Les-Gibson]

@rds999 

It might be worth checking if the Hybrid Connect does have it's own DHCP server and if so in what subnet it operates

[Keith_Beddoe]

Hybrid connect is just a modem which needs to connect to the BT Smart Hub 2 which provides the router function.

[rds999]

@Keith_Beddoe Thanks.   Saved me from a rabbit hole!  If the HC is just a modem, then it needs the router before the switch to do DHCP/NAT so the rest of the network can share the modem's public IP address.  

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[Keith_Beddoe]

Its purpose is to provide an alternative WAN connection should the primary WAN (fibre, or copper VDSL) become unavailable.

[Leasty]

I haven't had need to use the hybrid connect device as my main feed has been fine (famous last words) but will try it again when convenient - other members of the family working from home at the moment.

There has been a SmartHub 2 firmware upgrade since I last used the 4G so maybe that has introduced an issue? Firmware on my hub is v0.38.00.10147 and on the hybrid device is v0.22.03.202210140100-BT

My last "Resilience event" was 12/10/22 and I had the GS116 in place then, but lower level of firmware on the hub.

Your GS108PE has some management functions whereas the GS116 I use is a "dumb" switch, maybe that is a factor. I suggest you try with a non-managed switch as a start.

Will post the results of my test when I can.

[bensteventon]

I have my hybrid connect linked to the hub by Ethernet via two unmanaged switches - one Netgear and one TP Link. No issues and fails over correctly when tested, to the full 30/5mbps 

[Leasty]

@rds999 

Well, I've now tried hybrid connect failover in my setup - Netgear GS116 switch between hub and hybrid modem - and failover worked fine. Took about 4 minutes to switch over - about a minute before it started to failover (blue to flashing purple on the hub) after unplugging the cable to the NTE and another 2m30s for the failover to complete. Things worked fine on the hybrid modem albeit slower due to not having a great signal. 

I did have a problem failing back and after waiting about 10 minutes  had to power off/on the hub but it then all came back fine. Suspect it is as much to do with the hub not having been powered off in months and a firmware update happening during that time. Have got all the event log if you need anything from that.

I suspect your managed switch is the issue and would suggest trying with just a standard "dumb" switch.

Good luck

[rds999]

Thanks. I could try an unmanaged switch... it seems to be the way forwards. My managed switch is set up to do nothing on the relevant port, except IGMP snooping, so should not be a problem, but clearly is: I'm wondering if a VLAN is set up between the hub and HC when in fail over mode. I think my switch would reject those packets (though I'm at the limit of my knowledge). I'm going to leave the HC running over WiFi instead of a fixed connection as I shouldn't need it (again!) and *could* run a long cable through to it instead if I did!

Thanks to everyone for their suggestions and help.

[licquorice]

I'm intrigued to know the purpose of putting a switch between the HC and Hub.

[Leasty]

@licquorice I use a switch between the Hub and hybrid modem because of the distance between them and not wanting to lay extra cables.

My BT line comes in at the front of the house and is where the Smarthub is - provides wifi at the front of the house. The hybrid modem is upstairs at the back of the house in my study - just about as far away as it can be - to get the best 4G signal. That means there is only a poor wifi signal between the two.  I already have my main PC, NAS, AP and main switch in the study so it was a no brainer to put the hybrid modem on the switch as long as it worked. Means I have a cabled 1Gbps link between the Smarthub and modem.

If the 4G signal at the front of the house was good, I'd have the hybrid modem there, but no such luck.