this is actually not really solved since my old proxy provider is I can guarantee way better. I dont understand your problem of blocking some proxy providers. The Bright Data proxy pool quality is terrible... I have 2-3/10 success rates. It was something like 8-9/10 for my old provider.

Bright Data working is a strong signal Railway can make outbound proxy connections in general.

I would split this into two tests. First, from the Railway service, test the proxy itself with curl -v -x http://USER:PASS@proxyhost:port https://api.ipify.org.

If that times out, it is probably proxy auth, IP allowlisting, protocol mismatch, or the provider blocking cloud/datacenter origins. Some providers only allow the IP you registered from locally, so it works from your laptop but not Railway.

If that works but the target site fails, the target is probably blocking that proxy pool. ICMP_CSUM in flow logs can be noisy, so I would not use only that as proof Railway is blocking the provider. I would ask the old proxy provider whether Railway/cloud egress IPs need allowlisting and whether they support your Go client's exact proxy protocol from a Linux container.

Hello. Yes I'm sorry. However I still need something: the Railway IPs range. Basically my proxy provider only allows residential IPs using it, or whitelisted IPs. I'm sorry, this is my fault but this may be useful to anyone wishing to use proxies on railway, some proxy providers are like that.