From: John Dykstra <john.dykstra1@gmail.com>
To: Stephen Hemminger <shemminger@vyatta.com>
Cc: netdev@vger.kernel.org
Subject: Re: kernel dies if loopback device not intialized
Date: Wed, 17 Jun 2009 21:51:22 -0500 [thread overview]
Message-ID: <1245293482.10073.5.camel@merlyn> (raw)
In-Reply-To: <20090616215331.2a1bd276@nehalam>
On Tue, 2009-06-16 at 21:53 -0700, Stephen Hemminger wrote:
> The packets come from SNMP smux which opens a TCP socket over 127.1
> but the loopback interface is in admin down.
Hmmm...the stack is doing the ARP because it doesn't have a valid route
for 127.0.0.1. But I would expect it to be ARPing a default router, and
getting a response (modulo your network state). What am I missing?
> I suspect the packet
> bouncing from ARP is the TCP SYN packet which does not have a
> mac_header()
> because it is going over the (down) loopback.
Loopback packets have a L2 header--it's just not very interesting.
Even if they never got an L2 header added, skb->mac_header shouldn't be
garbage.
-- John
next prev parent reply other threads:[~2009-06-18 2:56 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-11 3:35 kernel dies if loopback device not intialized Stephen Hemminger
2009-06-15 15:41 ` John Dykstra
2009-06-17 4:53 ` Stephen Hemminger
2009-06-18 2:51 ` John Dykstra [this message]
2009-06-18 12:25 ` John Dykstra
2009-06-18 1:18 ` Stephen Hemminger
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