iproute2, alternative tables, no default route: routing trouble for localhost

[Покотиленко Костик <casper@meteor.dp.ua>]

Hi.

The task:

1. There 3 servers and a router with 2 PPPoE connections (let call them:
ppp0, ppp1).
2. There are several groups of Inet-clients to be served (Servers,
Clients and Club).
3. The task is:
   - to route Club through the ppp1;
   - to Servers and Clients through ppp0;

(Next is reproduced from memory and may be slightly incorrect)

router # netstat -nr
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt
Iface
192.168.1.0     0.0.0.0         255.255.255.0   U         0 0          0
eth0
a1.a2.a3.a4     0.0.0.0         255.255.255.255 U         0 0          0
ppp0
b1.b2.b3.b4     0.0.0.0         255.255.255.255 U         0 0          0
ppp1

router # cat /etc/iproute2/rt_tables
#
# reserved values
#
255     local
254     main
253     default
0       unspec
#
# local
#
#1      inr.ruhep
200 Servers
201 Clients
202 Club

router # ip rule ls
0:      from all lookup local
32763:  from 10.10.100.101/24 lookup Club
32764:  from 10.10.100.100/24 lookup Clients
32765:  from 192.168.1.0/24 lookup Servers
32766:  from all lookup main
32767:  from all lookup default

router # ip route ls table Clients
default via a1.a2.a3.a4 dev ppp0

router # ip route ls table Servers
default via a1.a2.a3.a4 dev ppp0

router # ip route ls table Club
default via b1.b2.b3.b4 dev ppp1

========================================

So, to summarize, the is no default route in main routing table. Each
group of clients is to be routed through its respective connection, and,
when its connection is down it is not to be routed.

This scheme works almost fine, 10.10.100.100/24 addresses are really
being routed through ppp0, 10.10.100.101/24 through ppp1 and
192.168.1.0/24 (3 Servers) through ppp0. BUT the router itself
(192.168.1.4) has no route to any host. I get "network is unreachable"
to any connectiion attempt from 192.168.1.4. And I can't connect to this
router from outside, because the packets have no route to be sent back.

I thought that there is different routing politics for localhost and
added default route to "local" table. 192.168.1.4 has started to have
the route, but the rest of the scheme started to work incorrectly.

So, the question is: how does the routing of packets comming from
localhost is being accomplished?

As to me there is a kind of "vicious circle" situation, because to enter
alternative routing table there should already be "source address", but
for localhost which have many source addresses it should decide which
route it needs to have the corresponding "source address" be set.

-- 
Покотиленко Костик <casper@meteor.dp.ua>