I would like to understand options for using two Balance 20X routers together to be redundant.
I have 4 WAN Connections A B C D.
Let us assume my constraints are to use these 4 WAN’s and two B20X routers and not other equipment.
If one B20X router fails the wireless devices on the network would be able to automatically reconnect to the remaining router wifi and still use/have the same DHCP reserved ip’s.
Wireless Devices would be in 192.168.1.0/24 and can freely roam between WIFI-A on B20X-1 and/or WIFI-A on B20X-2.
Each Device has a reserved DHCP IP. Wireless devices would keep the same static DHCP IP like 192.168.1.10 regardless if it was connected to WIFI-A on B20X-1 or WIFI-A on B20X-2.
B20X-1
192.168.1.1
WAN A ISP
WAN B CELL
SSID = WIFI-A (same password as WIFI-A on B20X-2)
B20X-2
192.168.1.2
WAN C ISP
WAN D CELL
SSID = WIFI-A (same password as WIFI-A on B20X-1)
How might I configure my two B20X to achieve this?
Network > High Availability, configure one 20X as master and the other as the slave, enable config sync.
For the “virtual IP” I’d probably change 192.168.1.1 to something else and use that as the VIP, I tend to follow some scheme along the lines of:
.1 - VIP
.2 - Router 1
.3 - Router 2
Connect a cable between a LAN port on 20X-1 and a LAN port on 20X-2 and you should be good to go.
The WAN side gets a bit more interesting, ideally you’d want to connect things in a symmetric fashion so both routers have the same upstream options more or less, are WAN A and WAN C different ISPs or the same thing?
If you are also expecting to have use of all 4 WANs at the same time as HA then you would need to get creative and I cannot also quite think of a way to do that without adding extra hardware , or possibly investigating the virtual WAN licence for the 20X… essentially though you would want to still use the HA features just without the config sync and then a number of VLANs on each router used to policy route traffic to specific WANs and a mess of spaghetti between the two 20Xs - we do something similar where we stack things together to make most use of the available WANs, but the 20X here lacks enough Ethernet WAN ports to do that the way I normally would.
WAN A ISP Primary (Comcast)
WAN B CELL Backup 1 (Verizon)
WAN C ISP Backup 2 (Century Link)
WAN D CELL Backup 3 (AT&T)
Attempting to use HA for this scenario story.
Normal connectivity via WAN A Comcast
2a) If WAN A Comcast fails then WAN B Cell backup (Verizon) takes over.
2b) If 20X-1 fails then 20X-2 takes over.
*question if both WAN A and WAN B Cell fail on 20X-1 in HA mode will the system automatically move to 20X-2 where there are WAN C and WAN D Cell on stand by ???
With 20X-1 in failure and 20X-2 operational WAN C (Century Link) takes over.
3a) If WAN C fails then WAN D Cell backup (AT&T) takes over.
If WAN D fails and no other WAN’s (A, B, C) are available then we have a critical incident.
4a) If 20X-1 is still failed and 20X-2 is also failed then we have a critical incident.
Its best to try think of the various WAN connections not as A/B/C/D but as what is in various priorities in each unit, and if possible I’d strive to connect both the Comcast and CL connections to both 20X, how you do that may depend on the handoff you have from them though, but it could be as minimal as a couple of dumb switches and adding a USB-Ethernet dongle to each 20X.
Set that to Priority 1 then in your config, put the Cell into Priority 2.
Config replication will do the same to the priority of the connections on 20X-2 so all good there, you may want to tick the box on the HA that keeps the standby connections alive.
Correct, just put it into a lower priority than the Ethernet WAN.
Yes, failure of 20X-1 should result in 20X-2 taking over, in testing depending on how the failure happens that’s normally a few seconds for me if I have a switch connected downstream to both the 20X LAN side and connect a test client to there and start pinging out.
They inherrit the same priority settings, so what you configure on 20X-1 will apply here unless you disable config sync and do things manually
