Linux-Hams archive - July 1997: confusion over routing with rspf

confusion over routing with rspf

Mike Bilow ()
Thu, 03 Jul 97 15:57:00 -0000


Simon J Mudd wrote in a message to Mike Bilow:

SJM> This is something Julian, who has configured ea4rct, has
SJM> pointed out, and he suggested that maybe this is a bug in
SJM> the linux kernel routing algorithm. This sounds worrying,
SJM> and a glaring mistake like this should have been found and
SJM> corrected a long time ago. That or something else is
SJM> happening.

SJM> I didn't think it was necessary to specifically name a route
SJM> to the hosts on a network interface, as this is implicit in
SJM> the device's configuration parameters, but maybe this is
SJM> something which must be done if dynamic routing is used.

I strongly doubt that there could be a glaring bug of this kind in the IP
routing code itself. It makes perfect sense to have the "ifconfig" command
imply a "route add" as if you typed it from the console, but then the effect
should be the same regardless of whether the route is implicit or explicit. If
no entry is made on the IP routing table, then the packets would not actually
get where they are going. It seems far more likely to me that someone jiggered
the /proc/net stuff to distinguish between implicit and explicit routes, and
that both rspfd the "route" command are messed up because of their dependence
upon /proc/net information -- but this is just a guess.

-- Mike