Subject: Re: altq 3.0 kernel interacts negatively with pppd?
To: None <>
From: Kenjiro Cho <>
List: tech-net
Date: 10/17/2001 19:34:58
Scott Presnell wrote:
> 	I've patched NetBSD 1.5.2 with altq-3.0  The build and install
> went fine, kernel build (with defaults options supplied by altq)
> went fine.
> I use a modified version of dip to contact my ISP (work), and have
> dip start pppd on the appropriate tty.
> I boot up the altq modified kernel, but I have not yet operated on 
> any altq devices or started altqd, etc.
> When I contact my ISP for a connection:
> 	1) dip is able to negotiate, and fire off pppd.
> 	2) the machine becomes unresponsive on all other network interfaces
> 		for a few (10?) seconds (machine has 3 ethernet interfaces).
> 	3) pppd disconnects.
> 	4) the machine interfaces come back to life.
> (log file follows at end of message)
> If I use otherwise the same kernel (not patched for altq, but same options)
> pppd can connect and operate correctly.
> I cannot find any reference to further conifgurational changes required...
> Is there something I need to do with altq to allow connections on ppp
> interfaces even though the other network interfaces seem to operate correctly?


> Or does this seem like a problem?

I'm afraid so.

Can you replace only "sys/net/if_ppp.c" by the original (unpatched)

The symptom indicates that net interrupts are blocked until ppp times
out.  I have no idea about how it is related to ALTQ, and I don't have
a ppp setup to test with at this moment.