After upgrading some devices to a build based on OpenWRT 19.07, revision r11325-616fff2a94, once the sysupgrade finishes, trying to connect via SSH from the management VPN to devices gives me this error:
ssh_exchange_identification: Connection closed by remote host
OpenSSH_7.9p1 Debian-10+deb10u2, OpenSSL 1.1.1d 10 Sep 2019 debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 19: Applying options for * debug2: resolve_canonicalize: hostname [ip] is address debug2: ssh_connect_direct debug1: Connecting to [ip] [[ip]] port 22. debug1: Connection established. debug1: identity file /root/.ssh/id_rsa type 0 debug1: identity file /root/.ssh/id_rsa-cert type -1 debug1: identity file /root/.ssh/id_dsa type -1 debug1: identity file /root/.ssh/id_dsa-cert type -1 debug1: identity file /root/.ssh/id_ecdsa type -1 debug1: identity file /root/.ssh/id_ecdsa-cert type -1 debug1: identity file /root/.ssh/id_ed25519 type -1 debug1: identity file /root/.ssh/id_ed25519-cert type -1 debug1: identity file /root/.ssh/id_xmss type -1 debug1: identity file /root/.ssh/id_xmss-cert type -1 debug1: Local version string SSH-2.0-OpenSSH_7.9p1 Debian-10+deb10u2 ssh_exchange_identification: Connection closed by remote host
Connecting via LAN works.
After a while the problem goes away and I'm able to get in also via the management VPN, but may re-appear intermittently shortly afterwards.
If I reboot the device, I don't see the problem anymore.
I could ignore it but it's a bit worrying, I had not seen this behavior before on previous versions.
Is anybody else experiencing the same issue?