more click/ip

[Eddie Kohler]

Hi Jacob, as far as I know:

IP broadcast packets should be sent to this machine, but not sent
further. There are multiple broadcast IP addresses, namely X.X.X.0 and
X.X.X.255. (I need to double check this.)

The last line is essentially crap. It says that anything that doesn't match
should be sent to output 1. TOriginally, it was sent to output 3, which was
hookued up to the LCS network, but in the configuration file we took out
the LCS-network output. We should have deleted the last line as well.

love
ed

> To: eddietwo at MIT.EDU
> Subject: more click/ip
> Date: Tue, 16 May 2000 20:09:59 -0400
> From: Jacob B Schwartz <quark at MIT.EDU>
> 
> 
> -- from the click sample router:
> -- // IP routing table. Outputs:
> -- // 0: packets for this machine.
> -- // 1: packets for 18.26.4.
> -- // 2: packets for 18.26.7.
> -- // 3: default route to LCS router.
> -- rt :: LookupIPRoute(18.26.4.24  255.255.255.255 0.0.0.0 0,
> --                  18.26.4.255 255.255.255.255 0.0.0.0 0,
> --                  18.26.4.0   255.255.255.255 0.0.0.0 0,
> --                  18.26.7.1   255.255.255.255 0.0.0.0 0,
> --                  18.26.7.255 255.255.255.255 0.0.0.0 0,
> --                  18.26.7.0   255.255.255.255 0.0.0.0 0,
> --                  18.26.4.0 255.255.255.0 0.0.0.0 1,
> --                  18.26.7.0 255.255.255.0 0.0.0.0 2,
> --                  0.0.0.0 0.0.0.0 18.26.4.1 1);
> 
> I'm curious what's going on in the configuration.
> 18.26.4.24 and 18.26.7.1 are presumably the IP addresses of
> each device, so a packet destined for that should go to the
> router itself.  18.26.4.255 and 18.26.7.255 are broadcast
> addresses, so that goes as well.  But what are 18.26.4.0
> and 18.26.7.0?  And aren't there several different types of
> broadcast addresses? (some get repeated and some don't I think--
> why do you only appear to handle on type of broadcast address)
> (If you wanted to send repeatable broadcasts locally and out to
> one of the networks, how would you do it in this configuration,
> out of curiosity?)  And what's the last line doing?