i386/112481: ppp.linkup example

[JD Bronson]

>Number:         112481
>Category:       i386
>Synopsis:       ppp.linkup example
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-i386
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          doc-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon May 07 13:40:00 GMT 2007
>Closed-Date:
>Last-Modified:
>Originator:     JD Bronson
>Release:        6.2
>Organization:
Aurora Health Care
>Environment:
6.2-STABLE FreeBSD 6.2-STABLE #0
>Description:
I am requesting to have the example ppp.linkup file changed to reflect the following (in some sort of way):

It seems that until commands specified with "! sh -c" are completed, no traffic is permitted under tun0.

Specifying "!bg sh -c" permits the process to be backgrounded and therefore does not hold up tun0 traffic and allows programs running within ppp.linkup to actually use tun0.

I discovered this when attempting to run 'nsupdate' to my DNS server to notify it of my newly obtained IP.

If I run it as "! sh -c", nsupdate HANGS forever.
If I run it as "!bg sh -c", nsupdate performs the requested actions.

I think it would be very helpful to add something into the ppp.linkup example files to indicate this.

-JD
>How-To-Repeat:
See above
>Fix:
Run commands with "!bg sh -c" 
instead of "! sh -c"
>Release-Note:
>Audit-Trail:
>Unformatted: