Comment 9 for bug 1928890

This issue is still present also on jammy 5.15. Some details that I found:

  - the purpose of this test is to verify that an ICMP6 packet is not forwarded by a virtual router if it needs to do fragmentation
  - the test creates 3 network namespaces representing host1, host2 and router
  - host1 and host2 have mtu 1500, router has mtu 1400
  - the test consists of a ping6 from host1 to host2 (via router) using a payload of 1450, so host1 and host2 don't need to fragment the packet, but router does
  - therefore the ping is expected to fail (and this is happennig), but we should also receive a "Packet too big" message from the router and we don't

So at the end the behavior is correct, but we're missing the "Packet too big" notification from ping. I'm not sure if it's a user-space issue (in iputils-ping) or a kernel issue.