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Immediate connect fail for X.X.X.X: Invalid argument

From: Aaron Bernardino via curl-users <>
Date: Tue, 23 Feb 2021 20:00:05 +0000

Using curl 7.59.0 inside a cri-o container in Kubernetes, I'm seeing the following error:

  Immediate connect fail for X.X.X.X: Invalid argument

This is when specifying argument --interface I don't encounter the error when not specifying --interface or specifying it with the non-loopback address/hostname instead. I'm also not able to use the interface name (i.e. eth0, lo).

It just hangs

The curious thing is that I don't encounter this w/ Docker in another Kubernetes cluster. I'm not sure if

there is something different w/ the containe networking in both of my environments but I think curl is

immediately responding back with an error when trying to do the socket connection. So the request hasn't been sent out yet.

Looking for tips on why curl would return an immediate error when the loopback interface is used.


Received on 2021-02-23