For a while I have been struggling with stalling downloads when running packagekitd and/or 'zypper dup' for openSUSE Tumbleweed on multiple systems. Until recently, I would send a 'kill -HUP <process>' to them to break the stall and restart the downloads. Since previously downloaded updates would be in the cache, this eventually would finish the downloads and successfully run the update. A couple of days ago I thought it might be interesting to see what would happen if I would just kill the stalled connection to the download servers with 'ss -K dst [download server address] dport = 80'. Bingo! Both packagekitd and zypper would immediately resume the download without further input. The connection to the download servers is native IPv6 (fiber) so I guessed it might be a PMTU problem. On my side of the connection MTU = 1500, so it is not likely that packets are being dropped on this end. The 'http://icmpcheckv6.popcount.org/' also shows no problems, so if there is a PMTU problem, it doesn't appear to be something I can fix. My question is, is this a known problem? Are there other people who see this? I have two systems on Tumbleweed, one connected through GigE and one through WLAN 5GHz. Both exhibit the same behavior.