bastion ssh login

Hi Fabric Team,

I was able to configure and create my first slice.

First minor thing: following instructions of the Jupyter Notebook configure.ipynb , I got this error message zip command not found. I solved the issue by running the following:

conda install zip

Also, I created this simplified ssh config file:

Host fabric-bastion
  Hostname bastion.fabric-testbed.net
  User scrgiorgio_0039551217
  ForwardAgent yes
  IdentityFile ~/.nsdf/vault/fabric/id_nsdf_fabric_bastion
  IdentitiesOnly yes
  StrictHostKeyChecking no
  ServerAliveInterval 120

Host fabric-slice
  Hostname 2620:103:a006:12:f816:3eff:fe70:52dc
  User rocky
  ForwardAgent yes
  ProxyJump fabric-bastion
  IdentityFile ~/.nsdf/vault/fabric/id_nsdf_fabric_slice
  StrictHostKeyChecking no

The ssh fabric-slice  works perfectly from a Fabric Jupyter Lab Terminal.

But it stuck if run from the “outside”. Debugging by ssh -vvvvv fabric-slice, I see the problem is that (*) from inside Fabric, the bastion node solves to 152.54.15.121; (*) from the outside, it solves to 128.163.180.149.

This is the log when it stuck:

ssh -vvvvvvv fabric-slice
OpenSSH_8.2p1 Ubuntu-4ubuntu0.4, OpenSSL 1.1.1f 31 Mar 2020
debug1: Reading configuration data /home/scrgiorgio/.ssh/config
debug1: /home/scrgiorgio/.ssh/config line 347: Applying options for fabric-slice
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: include /etc/ssh/ssh_config.d/*.conf matched no files
debug1: /etc/ssh/ssh_config line 21: Applying options for *
debug2: resolve_canonicalize: hostname 2620:103:a006:12:f816:3eff:fe70:52dc is address
debug1: Setting implicit ProxyCommand from ProxyJump: ssh -vvv -W '[%h]:%p' fabric-bastion
debug1: Executing proxy command: exec ssh -vvv -W '[2620:103:a006:12:f816:3eff:fe70:52dc]:22' fabric-bastion
debug1: identity file /home/scrgiorgio/.nsdf/vault/fabric/id_nsdf_fabric_slice type 2
debug1: identity file /home/scrgiorgio/.nsdf/vault/fabric/id_nsdf_fabric_slice-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.2p1 Ubuntu-4ubuntu0.4
OpenSSH_8.2p1 Ubuntu-4ubuntu0.4, OpenSSL 1.1.1f 31 Mar 2020
debug1: Reading configuration data /home/scrgiorgio/.ssh/config
debug1: /home/scrgiorgio/.ssh/config line 338: Applying options for fabric-bastion
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: include /etc/ssh/ssh_config.d/*.conf matched no files
debug1: /etc/ssh/ssh_config line 21: Applying options for *
debug2: resolving "bastion.fabric-testbed.net" port 22
debug2: ssh_connect_direct
debug1: Connecting to bastion.fabric-testbed.net [128.163.180.149] port 22.
debug1: Connection established.
debug1: identity file /home/scrgiorgio/.nsdf/vault/fabric/id_nsdf_fabric_bastion type 2
debug1: identity file /home/scrgiorgio/.nsdf/vault/fabric/id_nsdf_fabric_bastion-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.2p1 Ubuntu-4ubuntu0.4
debug1: Remote protocol version 2.0, remote software version OpenSSH_8.0
debug1: match: OpenSSH_8.0 pat OpenSSH* compat 0x04000000
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to bastion.fabric-testbed.net:22 as 'scrgiorgio_0039551217'
debug3: hostkeys_foreach: reading file "/home/scrgiorgio/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /home/scrgiorgio/.ssh/known_hosts:38
debug3: load_hostkeys: loaded 1 keys from bastion.fabric-testbed.net
debug3: order_hostkeyalgs: prefer hostkeyalgs: ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
Connection closed by 128.163.180.149 port 22
kex_exchange_identification: Connection closed by remote host

As you see, it’s not getting any reply to the SSH2_MSG_KEXINIT message.

Setting explicitly the bastion hostname to the working IP4 address 152.54.15.121fixes the problem, and I can always connect.

Thanks. G.