ProxySG has multiple default gateways configured. Default Route Failover takes more than a minute when the primary gateway becomes unreachable

Products

• ProxySG Software - SGOS

Issue/Introduction

There are two default routes on configured on proxySG as per the techdocs document 
Group 1 -> Default Gateway1 -> interface 0:0->Primary
Group 2-> Default Gateway2 -> interface 1:0->Secondary

When the Gateway1  connected to proxySG is brought down, the traffic still continues to egress out of proxysg interface 0:0 corresponding to Gateway1  and it takes more than a minute for traffic to egress out of proxysg interface 1:0 corresponding to Gateway2. So essentially the proxySG takes more than a minute to determine if the gateway is reachable.

Environment

ProxySG with multiple default gateways 

SS OS version below 7.3.19.1 (in 7.3 release train)

SG OS version below 7.4.3.1 (in 7.4 release train)

Cause

Previously, proxySG would send ARP requests every 90 secs to detect if the gateway is reachable.

Starting 7.3.19.1 and 7.4.3.1, proxySG now sends ARP requests every 10 secs to detect if the gateway is reachable. This, combined with the inbuilt ECMP health checks results in appliance now detecting unreachable gateway in 20-30 secs.

Resolution

Starting SG OS 7.3.19.1 and SG OS 7.4.3.1 , there have been improvements made with respect to detection of unreachable gateway
For networks that distribute traffic through multiple default gateways, the appliance now detects when a gateway is unreachable in 20-30 seconds. Previously, it could take over a minute to detect an unreachable gateway