action #181862
Updated by robert.richardson 5 days ago
# Observation I have noticed strange connection issues when trying to setup a VM on osiris-1.qe.nue2.suse.org (NUE-2 machine). Although the initial setup of a fresh leap image, including network connectivity, seems to be working fine (i can successfully ping and curl download.opensuse.org from within the VM), once i try to run any zypper command the connection will get stuck, without any output indicating what happened. I was suggested to run ping commands with a higher MTU value as @okurz assumed these issues may be related to that, which seems to be correct, as those ping commands would also get stuck. Similar network-related MTU For reference, similar issues have been reported where also mentioned by in a previous SD tickets: ticket https://sd.suse.com/servicedesk/customer/portal/1/SD-182364, as well in https://sd.suse.com/servicedesk/customer/portal/1/SD-142688. * [SD-182364](https://sd.suse.com/servicedesk/customer/portal/1/SD-182364) * [SD-142688](https://sd.suse.com/servicedesk/customer/portal/1/SD-142688) ## Steps How to reproduce 1. Create a fresh Leap 15.6 or Tumbleweed VM on `osiris-1`. a NUE-2 host such as osiris-1 2. Confirm that basic network connectivity works (`ping`, `curl` to `download.opensuse.org`). with download.opensuse.org 3. Run `zypper ref` and observe that it hangs without completing. 4. Alternatively, run: ```bash Try to run a zypper command such as zypper ref or run ping -Mdo -s1442 download.opensuse.org ``` and observe that it also hangs. ## Suggestions * Try another VM on osiris -> *DONE* ok1 also affected * Try on osiris-1 directly -> *DONE* not affected * Try make sure other non-salt controlled machines are not affected * Consider introducing a network diagnostic hook or health check script for VM post-boot validation. ## Workaround Manually set the MTU size within the affected VM to a lower value, like 1360: ```bash ip link set dev eth0 mtu 1360 ``` This allows `zypper` and other network operations to proceed without hanging.