Re: [Netconf] SSH question

[Martin Bjorklund <mbj at tail-f.com>]

Andy Bierman <andy at netconfcentral.com> wrote:
> Hi,
> 
> 
> You know about openssh, and the ClientAliveInterval messages
> that it sends (keepalive at openssh.com)?  The client is
> supposed to send data on the channel before N of these
> arrive.
> 
> It seems that libssh2 drops these messages.

Are you sure?  It's supposed to reply with an error if it doesn't
understand the request, since WantReply is set.

> But if the NETCONF manager wanted to answer,
> what can it send to the agent?  whitespace?
> an XML comment?
> 
> Is the agent supposed to handle (discard) non-PDU messages
> received on its channel? 

This is unclear.  At least the counter inBadRpcs will be incremented.
One school of thought says that if garbage is received, the session
should be dropped.

> What is the most interoperable
> way to send data to the agent without actually issuing
> an <rpc> and wasting resources?

I think you have to send an rpc.  kill-session on your own session id
should be cheap (just hope the server is 4741 compliant :)


/martin