A newbie question here...

My small business has a Vigor 2926 with a stable leased line on WAN1. LAN P1 is connected to a D-Link switch and then onto various users in my building. I have a backup connection on WAN2. All works fine.

My neighbour has an unreliable connection and also has a Vigor 2926. (I originally recommended it to him.) I will never use the bandwidth I have, so offered to share my internet with him.

I have set the VLAN configuration on "my" 2926 as follows:

VLAN0 - P1 - Subnet: LAN 1 (my traffic)
VLAN1 - P2 - Subnet : LAN 2 (for my neighbour)

So if his traffic goes through P2, it will be isolated from my traffic. I have enabled a DCHP server. It works if I plug a switch or PC into P2.

But my idea was to run P2 into the WAN1 port of "his" 2926. This way he keeps his existing setup. I effectively become his ISP on WAN1 with his old connection on WAN2 in case he loses the link to my office.

When I do this, the WAN1 light does not come on, though the lights on the socket light up. I have put his router back to factory defaults (having preserved his configuration) and still no joy.

Obviously I've misunderstood the way these things work and have been a bit naive. Is there anyway I can link the two Vigors together to achieve the goal which is essentially to offer him a "drop in replacement" connection on his WAN1 ?

Looking at the Vigor 2926 emulator @ http://eu.draytek.com:12926/ , I note that WAN 1 does not have DHCP enabled. Is this the default for the 2926 :?:

Check under "WAN >> Internet Access " -> "WAN1 Details". "IP Network Settings" that "Obtain an IP address automatically" is enabled; otherwise it needs to have an IP address in there that lies on the network of the DHCP range you are offering-out.

Assuming this is the issue, it should then take a step closer - but his 2926 is going to get one of your locally assigned IP addresses - rather than a public Internet Address. It will then have to NAT it on his LAN (which needs to be a different (private) address range). This double-natting is not ideal and may stop some things working

If you have a range of fixed IP addresses - which being a leased line, I suspect you might have - it would be better to split off a portion of this range, and make it available via the "IP Routed Subnet" option. Failing that, you could connect your 2926, to one of your neighbours 2926 LAN ports - and use it as a switch, rather than a NAT Router.

(Whichever method is used, you really need a healthy set of Firewall rules on each Router - to prevent the two LANs seeing one another).

(On a different note, I reckon you should think carefully about this altruistic offer. I can't see any benefit to you - but some potential issues if it goes wrong. For example, your ISP may not allow it contractually and might you be liable in law for anything emanating from your neighbours LAN? Also, what happens if your service becomes unavailable and impacts on your neighbour's business?
Perhaps, you could make it a failover solution, rather than his primary connection?)