Monitoring backend servers externally via ICMP

I have a simple setup in a test environment v13.1.1.2, with a virtual server and an associated pool with one member:

ltm node /Common/10.1.20.11 {
    address 10.1.20.11
}
ltm pool /Common/pool_http {
    members {
        /Common/10.1.20.11:80 {
            address 10.1.20.11
        }
    }
}
ltm virtual /Common/http_virtual {
    destination /Common/10.1.10.20:80
    ip-protocol tcp
    mask 255.255.255.255
    pool /Common/pool_http
    profiles {
        /Common/http { }
        /Common/profile_analytics { }
        /Common/tcp { }
    }
    source 0.0.0.0/0
    translate-address enabled
    translate-port enabled
}

I would like ICMP packets sent from my machine 10.1.10.1 to the virtual IP 10.1.10.20 to be forwarded to the backend server 10.1.20.11, and I would like to receive the replies.

If I look at the VIP configuration (Local Traffic ›› Virtual Servers : Virtual Address List ›› 10.1.10.20) I can see the "ICMP echo" configuration option, and the help section suggests the following:

"Specifies how the system sends responses to Internet Control Message Protocol (ICMP) echo requests on a per-virtual address basis. When enabled, the BIG-IP system intercepts ICMP echo request packets and responds to them directly. When disabled, the BIG-IP system passes ICMP echo requests through to the backend servers."

This does not happen (as verified with tcpdump), and if I understand K16885 correctly, then the instructions above are actually incorrect as the article says: "To prevent the BIG-IP system from responding to ICMP echo packets, you must disable ICMP Echo at the virtual address level."

So what method would you recommend to achieve my goal?