Re: [PLUG] IPv6 TCP connect timeout puzzler

2022-09-30 Thread Russell Senior
Just to follow up, I don't know why it had the effect I was seeing with TCP dump, but I did finally locate some network filtering in libvirt and observed that I saw the problem with Debian Buster as the hypervisor, but not with Debian Bullseye, and also noticed that Bullseye had a file:

Re: [PLUG] IPv6 TCP connect timeout puzzler

2022-09-09 Thread Russell Senior
On Fri, Sep 9, 2022 at 7:34 AM Paul Heinlein wrote: > On Fri, 9 Sep 2022, Russell Senior wrote: > > > I'm seeing bizarre behavior: host A initiates an ssh -6 to host B; host B > > is a qemu-kvm guest of a kvm host, C. Tcpdump (on the initiating host A > > shows A -> B TCP SYN packet, and a B ->

Re: [PLUG] IPv6 TCP connect timeout puzzler

2022-09-09 Thread Russell Senior
I don't think so. The initiating host gets the SYN-ACK like it should, just nothing happens to it. On Fri, Sep 9, 2022 at 11:43 AM Tomas Kuchta wrote: > Could the issue be that the ssh response is on ipv4, not on ipv6 as > expected? > > -T > > On Fri, Sep 9, 2022, 10:34 Paul Heinlein wrote: >

Re: [PLUG] IPv6 TCP connect timeout puzzler

2022-09-09 Thread Tomas Kuchta
Could the issue be that the ssh response is on ipv4, not on ipv6 as expected? -T On Fri, Sep 9, 2022, 10:34 Paul Heinlein wrote: > On Fri, 9 Sep 2022, Russell Senior wrote: > > > I'm seeing bizarre behavior: host A initiates an ssh -6 to host B; host B > > is a qemu-kvm guest of a kvm host, C.

Re: [PLUG] IPv6 TCP connect timeout puzzler

2022-09-09 Thread Paul Heinlein
On Fri, 9 Sep 2022, Russell Senior wrote: I'm seeing bizarre behavior: host A initiates an ssh -6 to host B; host B is a qemu-kvm guest of a kvm host, C. Tcpdump (on the initiating host A shows A -> B TCP SYN packet, and a B -> A TCP SYN-ACK reply, but host A apparently doesn't recognize it as

[PLUG] IPv6 TCP connect timeout puzzler

2022-09-09 Thread Russell Senior
I'm seeing bizarre behavior: host A initiates an ssh -6 to host B; host B is a qemu-kvm guest of a kvm host, C. Tcpdump (on the initiating host A shows A -> B TCP SYN packet, and a B -> A TCP SYN-ACK reply, but host A apparently doesn't recognize it as valid (although, in wireshark they look