I currently have a Gigabit link from my ISP and intend to get an additional Internet link from a different ISP sometime later this year,
for the purpose of redundancy/fault-tolerance (if one ISP fails), and also for general load-balancing the WAN traffic.
In the meantime I’ll test, ie. “simulate”, such a dual-WAN network setup over a single WAN link as follows:
<==> connected from/to multiple ports, ie. multiple patch-cables
<----> connected from/to single port, ie. single patch-cable
Multi-WAN-Router:
I’ve an EdgeRouter Lite-3 (by Ubiquiti) with 3 independent ports, and a ‘Load Balance Router’ TL-ER5120 (by tp-link) with 2+x WAN and 1+x LAN ports, 5 in total.
Not sure whether the ER-Lite3 can be used for this (it should, IMO), but with the TL-ER5120 it should be definitely possible as it’s intended exactly for such setups, but no experience with it yet.
I’ll try this setup later in few weeks as I currently have enough to do with the MT firewall, as well with RADIUS server/client setups (this is completely new to me).
Well to simulate multiple WAN’s towards the Multi-WAN-Router , then for outgoing connections it should be enough to change the
Single-WAN-Router(1x WAN, 4x same-subnet-LAN)
to
Single-WAN-Router(1x WAN, 4x different-subnet-LAN)
If this is a Mikrotik it can easily be done with the default config rules
by removing (some of) the LAN ethernet interfaces from the bridge, and giving them their own subnet , DHCP pool and DHCP server.
Add those ethernet interfaces to the LAN “interface list” , so that firewall access rules and NAT rules work as before.
The Multi-WAN-Router will see different subnets to connect to. It cannot know that those subnets come from the same ISP line, unless it checks the public IP address.
Rules and systems based on a different public IP address cannot be simulated.
(Solvable if you have more than one IP address and if those addresses come on the WAN interface of the Single-WAN-Router)
@bpwl, thanks for your input.
The problem with the Single-WAN-Router is that it’s an ISP router, ie. rented one, and it is more a consumer grade cable router where the user is very restricted in its setup. I’m 99% sure one cannot reconfigure it and assign individual subnets to each of its 4 LAN ports, ie. not permitted by its management software It is more intended to attach up to 4 PCs in the same one subnet.
Never mind, with the mentioned other routers it should be doable. I think.
Adding 2 NATting gateways of any brand between your ISP router and the Multiwan router in parallel will also do the trick, if you can somehow define the LAN subnet to be used in those gateways.
@bpwl, I’m not that a fan of NAT, as I want to keep the original IPs. Exception is of course the built-in NAT in the ISP-Router, that’s of course ok, and also necessary,
The cleanest solution seems to be to use all the 3 routers in series:
Btw, regarding the ISP-router I said upto 4 PCs in the same subnet, but one can of course attach some dumb switches to the 4 ports and by doing so attach theoretically as many endusers as needed, even more than 254 by cascading more switches and using a bigger subnet mask, like /23 or /17 etc…
[I haven’t tested that yet, but I think it should be possible]
Depends on your MultiWAN router test. If for the load balancing you don’t need different gateways and WAN IP addresses in different subnets to split/separate/loadbalance the traffic then indeed just direct connection will do (no extra hardware required). Your Multiwan router will get different IP addresses per WAN interface from DHCP or manual setting. I just hope then both devices are not using switches to create the LAN and WAN ports, what might create loops. (WAN ports are supposed to be isolated from each other).
@bpwl, since it’s a relatively small LAN, network devices like routers and switches here do use manually assigned static IPs only,
ie. no and never DHCP for these devices, as these devices are treated as servers and therefore need to have always a fix IP.
We also don’t use any DNS names for such network devices, just the IP b/c DNS server is another possible point of failure,
and adding/updating names in the “hosts” file on all the devices, PCs and servers would be a nightmare of work…
Static IPs are ok and just fine here.
Regarding creating possible traffic loops: I’m confident it can’t happen if one plans the routing well. A router passes everything to the uplink/gateway that does not go to the other ports, so… IMO a safe thing…
It is more intended to attach up to 4 PCs in the same one subnet.