Problems with multiple ISP connections

[ebzzry]

My gateway has three connections with the following
information summary:

ISP #1:
Connects to: DSL modem
Interface: vr0

/etc/rc.conf.isp1

...
defaultrouter="122.53.x.x"
ifconfig_vr0="DHCP"
ifconfig_vr1="inet 203.160.x.x/24"
ifconfig_fxp0="inet 192.168.0.1/24"
...

/etc/namedb/named.conf.isp1

...
forwarders {
    59.x.x.1;
    59.x.x.2;
};
...

ISP #2:
Connects to: DSL modem
Modem IP address: 192.168.1.1;
Interface: vr1

/etc/rc.conf.isp2

...
defaultrouter="203.160.x.x"
ifconfig_vr0="DHCP"
ifconfig_vr1="DHCP"
ifconfig_fxp0="inet 192.168.0.1/24"...

/etc/namedb/named.conf.isp2

...
forwarders {
    202.138.x.50;
    202.138.x.51;
};
...

/etc/resolv.conf contains

domain some.domain
nameserver 127.0.0.1

Where "N" in "ispN" is the number that denotes the connection
from above. Whenever I want to switch connections, I run a
script that basically does the following:

route delete default

ln -sf /etc/rc.conf.ispN /etc/rc.conf
ln -sf /etc/named/named.conf.ispN /etc/named/named.conf
ln -sf /etc/ipfw.rules.ispN /etc/ipfw.rules
cp -p /etc/resolv.conf.base /etc/resolv.conf

/etc/rc.d/natd restart
/etc/rc.d/routed restart
/etc/rc.d/named restart
/etc/rc.d/routing restart
/etc/rc.d/named restart

/etc/rc.d/dhclient stop

/etc/netstart

sh /etc/ipfw.rules

cp -p /etc/resolv.conf.base /etc/resolv.conf

Using ISP1 is fine, but when I switch to ISP2, I can't
get my internet connection to work? Where have I
erred?

ISP connection #2 gives IP addresses from 192.168.1.2
and onwards.

vr1 doesn't have an IP address associated with it
as shown by the `ifconfig' output after switching to ISP2.
I tried giving it an IP address by force, via

ifconfig vr1 inet 192.168.1.2/24

but this was the message that I got:

ifconfig: ioctl (SIOCAIFADDR): File exists

I tried removing the cable connection of connection #2 and plugged it
on a standalone FreeBSD installation with one NIC, and the connection
works.

I'm really stucked and I don't have a clue how to troubleshoot this.

[J65nko]

I get the impression that ISP-1 asks you to use DHCP, while ISP-2 gives you a static IP address.

In the configuration of ISP-1 through vr0, which gets an address through DHCP, you assign a static IP address to vr11.
In the configuration of ISP-2 through vr1, you assign IP addresses for both vr0 and vr1 via DHCP. Where is the static address assignment for vr1?

Don't know if that is the problem

Another possibility to use ISP-1 and ISP-2 would be to use pf and balance the traffic between these two ISP's. See
http://www.openbsd.org/faq/pf/pools.html#outgoing for an example.

[ebzzry]

The problem has already been fixed.

What happend was that I don't have a route to the second (vr1) connection.
I checked the routing table and added the appropriate route.