Junos OS

Hi, please suggest me which way is the best to achieve what I need as I kinda lost in the variants. It's probably a trivial question so the reply is probably just a link to the right article on topic.

I have the SRX 3xx as a gateway device. Hoster provides it with two Internet connections, e. g. two default routes. The device has several external subnets configured. I'm trying to figure how to:

1. Make some of the subnets working on both external links. It doesn't look like I can just set up the same subnets on both interfaces. It doesn't look like VRRP will help either. What else? Set up a separate routing instance? Set the subnets on lo0 and include it into the same security-zone as the internet links?

2. Make the internet connection redundant, e. g. stop using the default route in case it fails/start using it once it is available. What's here? Set the rpm probes?

3. Give the replies from the same external interface the request arrived on. Should I bother about it at all?

@andrei_C, I seen your reply which is now deleted (?). My question is much more simple than the one you answering to. I'm not trying to build a redundant solution on my own with the dynamic routing and whatnot. I'm just trying to utilize what I have in the right way (e. g. what would you do with two default routes in my case).

Hello,

In this case it's very strain forward way 

https://www.juniper.net/documentation/en_US/release-independent/nce/topics/task/configuration/internet-protocol-route-monitoring.html

PS:

Depending on how "critical" is for your Intenet availability - I would consider a 2nd ISP.

The formula I found some time ago is very simple - take the price of new ISP uplink and the "loss $" in case you lose your 1st ISP? If the amount of "loss $" is high then price 🙂 - you need it - if not - ignore it 🙂

PPS:

I also noted that my posts are somehow dropped ... maybe I am doing something wrong ;(

BR

Andrei