Dual ISP with web managed module

[BikeMan]

Dear all,

I have a lot of issue when I use redudant ISP in one location.

Cluster is managed through internet. So I have a default route to ISP1. Then I add a second isp in the dashboard with the default route involved in this ISP (related SK has been followed and configuration has also been checked several times).

It is more or less working: with standard client, no issue. But when I use phone (android or iPhone), unable to use Whatsapp or unable to follow a google search result (yes, I have a result when I search). 

Object are automatically NATted behind gateway.

We have checked the connectivity on each ISP (directly connected), and all is working fine.

We are using R8020T190. I have another location running R8020T141 without any issue.

I am a bit lost because I don't have any drop even with fw debug.

Is someone can help or give clue ?

Thanks,

[PhoneBoy]

I’m guessing this is a “route all traffic” configuration?
If different JHF levels are giving you different results, best to work with the TAC.

[BikeMan]

Hi,

I have searched and spend a long time, while solution was just in front of me. I suspected a MTU issue, so I add a look at the ISP side and to my ethernet linked to both ISP. To avoid frag and so on, I have defined small MTU on all involved interfaces (behind the ISP router, it is not ethernet...). But situation was not improved. Spending to times to tcpdump and so on, I noticed the coming packet from client devices were very, very small. Someone had defined in the past the VLAN interfaces linked to the specific network to 150. Physically, it was still 1500.  Upadted vlan MTU to 1500, magic ! Everything is working perfectly. Useres never had a so fast network. What I don't understand is why someone has defined MTU to 150. This is another topics, but for sure nerver trust a module you don't manage from A to Z...

[Chris_Atkinson]

150 seems like it's similar enough to be a typo of 1500.