Single proxy without a fallback entry
info
A return with a single PROXY entry gives the browser no alternative when that proxy is down. A second proxy in the list keeps inspection in place during an outage; what should happen when all proxies are down is a design decision (see PAC-X014).
Why it matters
Browsers fail over along the list and remember a failed proxy for a while. With one entry there is no failover: users get connection errors until the proxy is back. A second proxy (or a load-balanced VIP that already hides the failover) is the normal answer. The finding is informational because single-proxy returns are legitimate behind a highly available VIP; the author should confirm which case applies.
How to fix
List a second proxy ("PROXY p1:8080; PROXY p2:8080") or point at a highly available address.
Examples
Bad
function FindProxyForURL(url, host) {
return "PROXY proxy1.corp.example:8080";
}
Good
function FindProxyForURL(url, host) {
return "PROXY proxy1.corp.example:8080; PROXY proxy2.corp.example:8080";
}