This service will be undergoing maintenance at 00:00 UTC, 2016-08-01. It is expected to last about 1 hours

Bug 106279

Summary: Please include openssh/watchdog patch
Product: [Fedora] Fedora Reporter: Stig Hackvan <stig-redhat-bugzilla>
Component: opensshAssignee: Tomas Mraz <tmraz>
Status: CLOSED CURRENTRELEASE QA Contact: Brian Brock <bbrock>
Severity: medium Docs Contact:
Priority: medium    
Version: 3CC: dgunchev, mitr
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2005-02-07 09:19:05 EST Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:

Description Stig Hackvan 2003-10-04 15:06:52 EDT
Description of problem:

ssh connections die when left idle over a NAT router (timeout varies but is
seldomly configurable for appliance-class devices)


Additional info:

Please include in the redhat release the "watchdog/heartbeat" patches for openssh...

http://www.sc.isc.tohoku.ac.jp/~hgot/sources/openssh-watchdog.html

these allow the automatic transmission of occasional SSH protocol NOP packets
which keep the connection alive and prevent NAT timeouts and dropped connections.

-- stig
Comment 1 Stig Hackvan 2004-11-13 15:08:30 EST
hey nalin, can you bump this issue up a notch?  being able to preserve
connections over NAT (DSL routers, for example) boundaries is really
important these days.  every time i update redhat/fedora i have to
re-do these patches and fork my own rpms.

most people probably just suffer repeatedly dropped connections (with
screen, perhaps, on the far side so moderate the pain)...  all the
windows SSH clients i've seen can keep the connection alive, so why
can't the main branch?
Comment 2 Sitsofe Wheeler 2004-11-14 04:32:14 EST
It seems terribly broken that ssh connections would be dropped just
like that because they are idle. That seems like some broken/overly
aggressive firewalling.. 

On another note, aren't there a server side sshd_config options to
this (e.g. TCPKeepAlive or ClientAliveInterval spring to mind). Why
can't you get your server to set those?
Comment 3 Tomas Mraz 2005-02-07 09:19:05 EST
This is implemented in the current openssh-3.9p1 in FC3.

ServerAliveInterval, TCPKeepAlive are your friends.

See man ssh_config.