1. Scientific Computing Division File Transfers from/to SCD Supercomputers Siddhartha S Ghosh Consulting Services Group SCD/NCAR

2. Scientific Computing Division Current Security Policy Exposed Network UCAR Exposed Hosts gatekeeper ServersOffices Servers MSS Protected Network RAS VPN ssh, scp, sftp ftp, telnet, ssh, rcp/rlogin ssh Semi Exposed Network token + ssh Supers Data Analysis Super Net MSS roy token + ssh ssh scp sftp

3. Scientific Computing Division Options 1.Invoke scp/sftp from Supers to remote Computers 2.Invoke ftp-proxy from Supers to remote Computers 3.Invoke scp from remote Computers to roy.ucar.edu 4.Invoke scp from Supers to salo-s.ucar.edu and a following scp from remote Computers to salo and vise-versa. 5.Stage into MSS and download using ftp/TLS to peewink.ucar.edu

4. Scientific Computing Division Invoke scp/sftp from Supers to remote Computers Most convenient, may be automated through scripts by Installation of ssh-keys. Secure Ref: http://www.scd.ucar.edu/docs/ibm/scp.html Caveats Remote site must allow incoming ssh Little computational overhead for encryption/decryption

5. Scientific Computing Division Invoke ftp-proxy from Supers to remote Computers Issue ftp roy-s from Supers At the proxy prompt give username@remote-host.remote-domain Follow usual ftp syntax Convenient for anonymous remote ftp access Caveats - Remote site should allow incoming active mode ftp connection - Password for remote account is transmitted in clear - Few reported cases of failures particularly when remote ftp server is behind a firewall

6. Scientific Computing Division Invoke scp from remote Computers to roy.ucar.edu Scp files from remote computers to username@roy.ucar.edu:supercomputer-name Periodically roy transfers those files to username@supercomputer:/ptmp/username/file Some ssh key and other setup is required, Ref: https://www.scd.ucar.edu/docs/access/internal/inbound.html Caveats: - Only works for inbound transfers

7. Scientific Computing Division Invoke scp from Supers to salo-s.ucar.edu following scp from remote Computers to salo and vice versa. Works when remote site too is hardened Transfer to salo (3 rd machine) username@salo.ucar.edu:ptmp Pick it up from salo within 2 hrs. (Refer to the last section of previous reference) Requires account in salo, please email consult1@ucar.edu.

8. Scientific Computing Division Stage into MSS and download using ftp/TLS to peewink.ucar.edu Convenient, if it needs to be archived in MSS anyway May be used for transferring files in both ways. Ref: http://www.scd.ucar.edu/docs/mss/ftp.html Caveats - Installation of ftp/TLS client is required, (usually straightforward in Linux) - MSS holdings and transfers incur charges.

9. Scientific Computing Division Installation of ssh-keys in roy This is described in the web page referred to earlier. Create key in your remote computer: ssh-keygen –t rsa press at passphrase prompts Grab the.pub key using mouse type “key roy” when prompted type “key supercomputer-name” e.g. “key bluesky” and type passwd for bluesky when prompted. Once completed you can do: automated file-transfers (method-1) You only need to give One Time Crypto passwd while logging into the supercomputers.

10. Scientific Computing Division Conclusion All the options have little caveats attached Things will change for the better for the users in near future, we have been exploring different options Questions ?