Port Forward Limit?

Todd Morgan bamamorgans at gmail.com
Sat Sep 27 06:01:49 EST 2014

At my company we use port forwarding as an alternative to VPN. In previous
releases of openssh (pre 6.0) we could run a script and fetch the thousands
of forwards to our local machine to connect to remote machines. Since
openssh 6.x, whenever we run the same script we get a bufferoverflow error.

debug1: channel 4577: new [port listener]
debug1: channel 4578: new [client-session]
debug1: Requesting no-more-sessions at openssh.com
debug1: Entering interactive session.
*** buffer overflow detected ***: ssh terminated
======= Backtrace: =========

I assume this is a security measure to thwart overflow attacks. I've tried
utilizing multiplexing, but received the same type of buffer overflow.

Are there any settings that I can change to allow for more forwards? At the
moment we have a work around to only pull back ports in batches but that
isn't a long term solution.

Any advice would be appreciated. Thanks

-Todd Morgan

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