Why is the first of two post-up commands for routing in interfaces configuration not automatically processed

Question

We managed to connect our servers to two distinct networks and everything works fine. We use routing rules that ensure that server responds to the right network.

I followed the instructions under this link: http://www.thomas-krenn.com/en/wiki/Two_Default_Gateways_on_One_System#Configuring_the_New_Routing_Table

Now I encounter the following problem: I I restart the server, only one routing-configuration (rt3) is established. Only the second set of post-up commands seems to work automatically.

I can solve this problem easily buy then executing the first set of post-up commands (rt2) manually and everything will be working as expected.

But of course the post-up commands should be executed automatically.

This is our interfaces-file:

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
allow-hotplug eth0
iface eth0 inet static
address xxx.xxx.xxx.xxx
netmask 255.255.255.0
broadcast xxx.xxx.xxx.xxx
gateway xxx.xxx.xxx.xxx
dns-nameservers xxx.xxx.xxx.xxx xxx.xxx.xxx.xxx 4.2.2.2 8.8.4.4
post-up ip route add xxx.xxx.xxx.xxx/24 dev eth0 src xxx.xxx.xxx.xxx table rt2
post-up ip route add default via xxx.xxx.xxx.xxx dev eth0 table rt2
post-up ip rule add from xxx.xxx.xxx.xxx/32 table rt2
post-up ip rule add to xxx.xxx.xxx.xxx/32 table rt2

# The secondary network interface
auto eth1
allow-hotplug eth1
iface eth1 inet static
address xxx.xxx.xxx.xxx
netmask 255.255.255.0
broadcast xxx.xxx.xxx.xxx
gateway xxx.xxx.xxx.xxx
dns-nameservers xxx.xxx.xxx.xxx xxx.xxx.xxx.xxx 4.2.2.2 8.8.4.4
post-up ip route add xxx.xxx.xxx.xxx/24 dev eth1 src xxx.xxx.xxx.xxx table rt3
post-up ip route add default via xxx.xxx.xxx.xxx dev eth1 table rt3
post-up ip rule add from xxx.xxx.xxx.xxx/32 table rt3
post-up ip rule add to xxx.xxx.xxx.xxx/32 table rt3

Once executing the commands for rt2 manually, everything is perfect and we had this configuration running for weeks without any issues.

the rt_tables file is as follows:

#
# reserved values
#
255     local
254     main
253     default
0       unspec
#
# local
#
#1      inr.ruhep
1 rt2
2 rt3