On Fri, 29 Sep 2023 14:45:05 -0400, Joe Salmeri wrote:

> Could there be a firewall blocking it ?

Actually, this got me to thinking - in the host there isn't any firewall
configuration blocking it, but in the network namespace provided by
slirp4netns, that might be a different issue.  I've no idea where that
iptables firewall configuration comes from, but it definitely is different
in my setup than the host (which makes sense to me).

What the failures are showing for the two who are seeing them is an ICMP
response failure from the gateway in the rootless network namespace to the
tap0 interface that's defined in the namespace (ie, 10.0.2.2 is the
gateway, 10.0.2.100 is the tap0 interface within the namespace).

It seems almost certain to be something within this virtual userspace-
defined network.

--
 Jim Henderson
 Please keep on-topic replies on the list so everyone benefits