[Babel-users] Duplicating externals

[Juliusz Chroboczek]

> Please try this patch, running Babel with ``-A''.

Er, slightly more complicated than that.

You'll need to patch babel-pinger (see below) and run

  babeld -k 2048 -A 2048

The idea is that with -A, we use the kernel priority to choose between
Babel and external routes.  So babel-pinger needs to install its route
at a priority that less than the priority that Babel uses.

Note that if you weren't using babel-pinger, you wouldn't need to use
multiple routing tables with this patch -- it'd just work out of the
box with the right -k and -A values.

(I'm using priority, rather than metric, to avoid confusion between
routing protocol metrics and kernel priorities -- they are orthogonal
concepts.  Cisco uses the term ``administrative distance'', which you're
welcome to google.)

                                        Juliusz

diff -rN -u old-babel-pinger/babel-pinger.c
new-babel-pinger/babel-pinger.c
--- old-babel-pinger/babel-pinger.c     2009-11-07 18:53:06.032768279
+0100
+++ new-babel-pinger/babel-pinger.c     2009-11-07 18:53:06.032768279
+0100
@@ -407,7 +407,7 @@
     char buf[100];
     if(!installed) {
         snprintf(buf, 100,
-                 "ip route add 0.0.0.0/0 dev lo metric 65534 proto %d",
+                 "ip route add 0.0.0.0/0 dev lo metric 1234 proto %d",
                  protocol);
         system(buf);
     }