SSH slow to ask for password

Question

There is a similar question about slow logins here, but I believe my issue is different. Read on...

I usually use my Pi headless, SSHing in from my Macbook over WiFi. When I do, it usually takes 10-20 seconds for the password prompt to appear. While it isn't the end of the world, it is annoying.

I ran the ssh command with the -vvv parameter and this seems to be where the problem is:

debug1: Trying private key: /Users/Name/.ssh/id_rsa
debug3: no such identity: /Users/Name/.ssh/id_rsa
debug1: Trying private key: /Users/Name/.ssh/id_dsa
debug3: no such identity: /Users/Name/.ssh/id_dsa
debug2: we did not send a packet, disable method
debug3: authmethod_lookup password
debug3: remaining preferred: ,password
debug3: authmethod_is_enabled password
debug1: Next authentication method: password

It seems it is looking for keys that are not there before finally asking for a password (where I have placed Name is actually my Macbook user name). As that path is obviously on my Mac I assume the problem lies that way, but I don't know - it could be the Pi. Performance is fine once I've logged in. Does anyone have any suggestions?

Have you tried disabling dns from your ssh server ? (see https://www.turnkeylinux.org/blog/slow-ssh ) — lord.garfield, Jun 27 '17 at 14:03

score 2 · Answer 1 · answered Jul 23 '14 at 01:01

You may also find it useful to copy an SSH key to the Pi so you don't need to enter a password each time you connect. To do that, first check if you've already got a public ssh keyfile:

ls ~/.ssh/id_rsa.pub

If you haven't, you can generate one with:

ssh-keygen -t rsa -C "your_email@youremail.com"

Finally, copy the keyfile to ~/.ssh/authorized_keys on the Pi (there's a few different ways to do this, I used Transmit to copy it over SFTP, since I'm a Mac user. Windows users have WinSCP, and Linux users probably already know how to do it ;) ). This file contains all of the keys authorised to connect to the Pi, so will probably be blank or non-existent on a new Pi. If so, just copy id_rsa.pub to this location. If it already exists, add the key from id_rsa.pub to the end of the file.

score 1 · Answer 2 · answered Jul 22 '14 at 14:29

1

You have two choices:

disable all authentication methods except the password
generate RSA keypair and copy the public part to your RPi (preferred)

answered Jul 22 '14 at 14:29

lenik

11,541
1
30
37

Ok - how do I do the latter? – user8543 Jul 22 '14 at 14:32
google for "generate RSA keypair mac" ? – lenik Jul 22 '14 at 14:35
Wouldn't it be nice if Googling that had a chance of finding your extremely helpful answer here on Stack Exchange? – user8543 Jul 22 '14 at 14:37
sorry, I don't have mac, googling that particular query is totally useless for me because I cannot prove, disprove or approve the standard ssh-keygen/copy-id method due to the lack of hardware. – lenik Jul 22 '14 at 15:35

SSH slow to ask for password

2 Answers2