"
Well, sadly, it wasn't the MTU. I can't find out what happened and had to remove opnsense from my network. I could trace it down to timeout errors, but couldn't find the right way to repair it.
So what I was able to see: By logging in with ssh as root and executing something like this:
truss -fdD fetch http://mirror.fra10.de.leaseweb.net/opnsense/FreeBSD:11:amd64/20.1/
I would see something like this:
0.105005698 0.000020700 read(3,"<!DOCTYPE html PUBLIC "-//W3C//D"...,1651) = 1651 (0x673)
15.105096928 15.000018920 read(3,"\r",1) = 1 (0x1)
15.105185998 0.000018960 read(3,"\n",1) = 1 (0x1)
15.105316468 0.000025120 read(3,"4",1) = 1 (0x1)
15.105436228 0.000048200 read(3,"5",1) = 1 (0x1)
15.105554448 0.000019800 read(3,"0",1) = 1 (0x1)
15.105655648 0.000019000 read(3,"\r",1) = 1 (0x1)
15.105741818 0.000018680 read(3,"\n",1) = 1 (0x1)
33.105861038 18.000020730 read(3,"/opnsense/FreeBSD:11:amd64/20.1/"...,1104) = 1104 (0x450)
What this means: data flows so slowly that the connection effectively timeouts. It took 15 to 18 seconds for receiving 1651 bytes. I also did a tcpdump and could see the TCP resets. But this didn't helped me to repair the connection. I played around with the MTU on all network interfaces that are under my control (my machine, opnsense, proxmox), but to no avail.
I would be very happy to be able to use opnsense, so if someone knows how to deal with problems like that, please let me know!
So what I was able to see: By logging in with ssh as root and executing something like this:
truss -fdD fetch http://mirror.fra10.de.leaseweb.net/opnsense/FreeBSD:11:amd64/20.1/
I would see something like this:
0.105005698 0.000020700 read(3,"<!DOCTYPE html PUBLIC "-//W3C//D"...,1651) = 1651 (0x673)
15.105096928 15.000018920 read(3,"\r",1) = 1 (0x1)
15.105185998 0.000018960 read(3,"\n",1) = 1 (0x1)
15.105316468 0.000025120 read(3,"4",1) = 1 (0x1)
15.105436228 0.000048200 read(3,"5",1) = 1 (0x1)
15.105554448 0.000019800 read(3,"0",1) = 1 (0x1)
15.105655648 0.000019000 read(3,"\r",1) = 1 (0x1)
15.105741818 0.000018680 read(3,"\n",1) = 1 (0x1)
33.105861038 18.000020730 read(3,"/opnsense/FreeBSD:11:amd64/20.1/"...,1104) = 1104 (0x450)
What this means: data flows so slowly that the connection effectively timeouts. It took 15 to 18 seconds for receiving 1651 bytes. I also did a tcpdump and could see the TCP resets. But this didn't helped me to repair the connection. I played around with the MTU on all network interfaces that are under my control (my machine, opnsense, proxmox), but to no avail.
I would be very happy to be able to use opnsense, so if someone knows how to deal with problems like that, please let me know!
