Q: Lan interface and snoop

[Fernando Cela Diaz <fcela@ce.chalmers.se>]

I have read your email and I wonder if you know how to trace the internal
state of the MAC sublayer of each computer plugged to the lan, ie current
retransmission number, current backoff etc... Do you know how to do that?

Thanks,

/FCD

----------------------------------------------------------------------
Fernando Cela
email: fcela@ce.chalmers.se                     phone: +46 31 772 1709



On Sat, 31 Jul 1999, Gurvesh Bhutiani wrote:

> Hi,
> 
> I am trying to get the snoop implementation to work in ns2.1b6
> 
> In snoop.tcl, the wireless part is actually a Lan with an errormodel. The
> tcl code from snoop.tcl is as follows:
> 
> proc add-error {lan src dst errmodel} {
> 	$lan instvar lanIface_
>        
> 	set nif $lanIface_([$dst id])
> 	
> 	set filter [new Filter/Field]
> 	$nif add-receive-filter $filter
> 	$filter filter-target $errmodel
> 	$errmodel target [$filter target]
> 	$filter set offset_ [PktHdr_offset PacketHeader/Mac macSA_]
> 	$filter set match_ [$src node-addr] # will not work with hier.
> routing
> }
> 
> The problem is that I cannot access the LAN interface  and I
> get the following error:
> 
> ^^^^^^^^^^^^^^^^^^^^^^^^^^
> can't read "lanIface_(1)": no such element in array
>     while executing
> "set nif $lanIface_([$dst id])"
>     (procedure "add-error" line 4)
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>  
> Could some one tell me what to do about this ?
> 
> Thank you in advance.
> 
> Gurvesh Bhutiani
> ----------------------------------------------------------
> 
> 
>