I'm trying to connect to a number of hosts using pssh in combination with a jump host and ssh-agent key forwarding.
Unfortunately this fails quiet regular, but with different hosts failing on. So this is only an example which would look different next time:
~> pssh -h /tmp/hostfile -o /tmp/log -e /tmp/error/ -v uname -a  13:51:18 [FAILURE] host1 Exited with error code 255  13:51:19 [SUCCESS] host2  13:51:19 [SUCCESS] host3  13:51:19 [SUCCESS] host4  13:51:19 [SUCCESS] host5  13:51:19 [SUCCESS] host6  13:51:19 [SUCCESS] host7 ….  13:51:19 [SUCCESS] host16
When having a deeper look, I'm getting
ssh_exchange_identification: Connection closed by remote host ssh_exchange_identification: Connection closed by remote host
on the host that failed. This looks much like the ssh-agent keyforwarding via jump host did not work in this particular scenario.
Inside my ~.ssh/config it looks like this:
ForwardAgent yes Host *.tld.foo User frlan ProxyCommand ssh tld-jump-host nc %h %p Host tld-jump-host HostName myhost.example.com User frlan ProxyCommand none
Usually this is working. Now I'm wondering why starting at about 15 hosts sometime the key is not forwarded an dhow I can upgrade my configuration to prevent this from happening.