tcpdump - tun/tap virtual interfaces

[Giovanni P. Tirloni]

* Robert Watson (rwatson at freebsd.org) wrote:

> Do you see anything when you ping the broadcast address or other foreign
> address of the tap interface?  Packets delivered to local IP addresses
> generally don't go out an interface. 

 About Ethernet frames not going out to the wire and being sent to the
 loopback..
 
 The check seems to happen at line 291 in if_ethersubr.c and then it
 uses the if_simloop() function to copy the packet to the loopback
 interface. Is that right? 

 The rcvif interface is set to the hardware device, how is this used in
 this case? What kind of checks are done to the rcvif usually?

 I haven't received my copy of Steven's Volume 2 yet so if it's
 explained there (as I hope) I will sit in my corner and wait to for it
 patiently :)

 --
 Giovanni P. Tirloni <gpt at tirloni.org>
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