Dual WAN Failover Reliability?

[pendetim]

I am considering using the Dual WAN in Failover mode on a RT-AC68 with 3.0.0.4.384.32799. The WAN connection is a cable modem, 30x3mbps speed and the LAN1 will be a DSL modem ,3.0 x0.78 speed. All values in the ASUS will be left at factory defaults for failover and fail back with a ping to google.com for detection.

How reliable is this setup now? I understand ASUS had some bugs to workout a few years ago. Have they been able to polish things a little and make it work reliability?

 

[peraburek]

Asus DualWan is FUBAR. I have used failover and failback, and it left me without any Internet connection just because Asus got stuck in loop "WAN Connection: Fail to connect with some issues." I have asked explanation from Asus support but they don't have jack clue.

I have been using Cable modem feeding Public IP to Asus WAN interface as primary WAN

Asus secondary WAN is USB 3G/4G Huawei E3372 LTE modem

If you want working Failover and Failback go for Synology routers, it just works ridiculously well, I have tested it extensively last week with Synology RT2600AC

There is NO dropped packets during connection switch on Synology (testing with ping 8.8.8.8 and ping 1.1.1.1)

I have been reporting dual wan bugs to Asus support for about a year, and they still didnt't resolved this problem, they lack the knowledge, logic and effort to resolve root cause of the issue.

Asus dualwan code called wanduck.c is a mess. Nobody wants to touch this so it is asus dualwan fubar status quo for a few years already.

 

[peraburek]

here is guide how to report BUGs
https://www.snbforums.com/threads/beta-dual-wan-helper-script-v1-0-beta-3.40401/page-8#post-412417

please don't join dark side, submit your issue and help us fight against Asus ignorance, in order to get decent DualWAN functionality
there is no other way than to overwhelm Asus support until it gets from bottom to head that users wouldn't be complaining if DualWAN was actually working

https://www.asus.com/support/FAQ/1011719/

 

[pendetim]

I went ahead about a week ago and setup the Asus Rt-AC68 as a dual wan with failover/failback. I had nothing to loose if it did not work as reverting to single WAN would be easy.

After a week of using it and testing simulated and real failures from the cable WAN, I can report that it seems to be working well. While I did not expect zero loss switching, it does poll the primary WAN and if it gets no response after the set numbe of tries, the DSL connection becomes primary. When the cable WAN comes back, it switches back to the WAN1 connection.

So for what I am doing, this seems to be a winner.

PS, I do realize that by saying this, all hell will break loose tonight and everything will stop working. LOL

 

[peraburek]

@pendetim - how did you test?

if your primary WAN is cable connection (probably cable modem in bridge mode) - I guess you have tested by pulling out UTP cable from WAN port on ASUS ? if yes, then it is super easy for ASUS, it detect that WAN port is down and it does failover

still it will interrupt your connection every X seconds checking for failback for no reason

however if you simulate Internet outage (real life scenarion) by disconnecting COAX cable on your cable modem, leaving UTP connected from cable modem to Asus router WAN port (WAN port status up), Asus router will do nothing

if you enable "Enable ping to Internet" and define target like "8.8.8.8" or something you want, only ONE lost packet will cause false alarm and connection switch, so you will end up with jumping from WAN1 to WAN2 and vise-versa, because Asus Firmware Developers are not able to understand the concept of FALSE ALARM

here are youtube video underlining my claims and tests
sorry for mediocre video quality, I have sent those videos to ASUS Firmware Developers, because they do NOT understand that failover is NOT working in REAL-LIFE

I told Asus developers to add at 3 watchdog targets like: 8.8.8.8 ; 1.1.1.1 ; 208.67.222.222 so if ping fails to ALL destination targets, connection switch should happen

however there are certain things to consider, some ISPs block ICMP if used extensively, so checking HTTP as additional watchdog is much better way to do it, if ICMP fails

here is excellent script from @Martineau

Monitor WAN connection state using PINGs to multiple hosts, or a single cURL 15 Byte data request and optionally a 12MB/500B WGET/CURL data transfer

https://pastebin.com/iDRDjaGV

there is no option to define Failover status:
1. Power Saving (WAN2 port down, not connected)
2. Cold-Standby (WAN2 port up, but not connected)
3. Hot-Standby (WAN2 ready AND connected, for faster connection switch)

Failback should be tested in the background without interrupting your Internet connection

it is no rocket science
I have exchanged at least 80 e-mails with ASUS, but they are ignorant
Synology got DualWAN (called SmartWAN) right,

I have sent Asus Martineau's script, if they would replace buggy wanduck with Martineau's script it would do wonders

I have respect for Merlin's great work, as well as other members of community, but Asus should be sued for false claims, marketing routers as "Dual WAN" capable

 

[Livin]

@peraburek
Thank you for the excellent info. Question... I use Merlin, is it any better on that?

I tried 4G Failover using Netgear LB2120 but it looks to have major issues. One already cost me $70 in 4G costs on the first day ... It didn't fail-back! Oddly, it seems there was no outage and should have never failed to begin with. I think similar to the ASUS issue where a single lost ICMP response made it fail over.

So, I was looking at getting a USB 4G LET device for ASUS Dual WAN but I think you convinced me not to.

I'm also considering getting Yeacomm YF-P11 4G LTE Router as a few on the Netgear forum switched to those.

thx for the input!