OpenSSH SFTP - worked 9/6 and now it doesn't

[VilenaRP]

Hi all,

I'm hoping someone can point me in the right direction. I have set up SFTP on system running V5R4 (an upgrade is not in the works). I had it working on 9/6/14 but when I tried to connect last night (and tonight) I keep getting a connection closed message. Below is what I get when I try to log in manually. I have not changed any settings and port 22 is open. Since the iseries will be initiating the connection I have set it up as a client only. I am at a loss as to why this will suddenly not work.

Connecting to b2b100qa.volvo.com...
OpenSSH_3.5p1, SSH protocols 1.5/2.0, OpenSSL 0.9.7d 17 Mar 2004
debug1: Reading configuration data /QOpenSys/QIBM/ProdData/SC1/OpenSSH/openss
h-3.5p1/etc/ssh_config
debug3: Seeding PRNG from /QOpenSys/QIBM/ProdData/SC1/OpenSSH/openssh-3.5p1/l
ibexec/ssh-rand-helper
debug1: Rhosts Authentication disabled, originating port will not be trusted.
debug1: ssh_connect: needpriv 0
debug1: Connecting to b2b100qa.volvo.com [192.138.117.118] port 22.
debug1: connect to address 192.138.117.118 port 22: A remote host refused an
attempted connect operation.
ssh: connect to host b2b100qa.volvo.com port 22: A remote host refused an att
empted connect operation.
Connection closed


Thanks,
Vilena

[DeadManWalks]

Re: OpenSSH SFTP - worked 9/6 and now it doesn't

Perhaps there has been a change on the b2b100qa.volvo.com server. They deleted the key? Changed the key? Blocked the ip and or port?

[Scott Klement]

Re: OpenSSH SFTP - worked 9/6 and now it doesn't

The error message "A remote host refused an attempted connect operation." means that the SSH server is not running on that computer. Perhaps someone forgot to start it?

[VilenaRP]

Re: OpenSSH SFTP - worked 9/6 and now it doesn't

Interesting, Scott. I hadn't considered that. I have sent an email to my contact asking them to look into their side. Thanks!

[VilenaRP]

Re: OpenSSH SFTP - worked 9/6 and now it doesn't

hi all,

Turns out that the server was blocking a range of ip addresses and I just happened to be in that range. So my connection issue is now solved. On to a new problem in the same project.

Thanks for your help!

[tomliotta]

Re: OpenSSH SFTP - worked 9/6 and now it doesn't

IMO, the use of the word "refused" in that message (and similar messages about other servers or services) was a mistake. It's too close to "rejected", and the two words are too easily confused.

As a rule of thumb for such messages in IBM i, "refused" practically means that no connection happened with the intended service. Maybe the service isn't running, maybe a firewall is in the way, maybe...? Whatever the reason, there was no signal coming back that says the connection is active and whatever exchange is needed next can proceed. "Refused" effectively means "No answer."

And "rejected" generally means that a connection attempt got through to the coded service, but the service itself found some reason to drop the connection. You can often expect that some kind of diagnostic indication will also be returned that gives at least a hint about what was wrong. E.g., a user ID or password might be wrong. Those could only be verified if the connection actually got initially established in order for those values to be received, so that's when the idea of "rejected" comes in. ("I looked at what you sent, and I reject your offer,")

A "refusal" generally comes because of some intermediate component between you and the remote server/service rather than from any code in the server/service.

A "rejection" generally comes via the remote server/service itself, perhaps (e.g., on IBM i) because an exit program returned with the 'Reject' flag set.

The difference doesn't always hold when checking messages on other platforms. And I think I've seen at least one exception somewhere in the AS/400 line. But, IMO, it's one of the best starting points for us on our platform as long as a starting point is needed.