freebsd gateway: 3 networks - 3 nic

[Andras Kende]

Hello,

I have the following setup in a school:

Freebsd 5.2.1 with ipfilter ipnat.

Network card 1 = fxp0 fractional T1 line (512kb) 64.140.xxx.xxx static
public ip
Network card 2 = xl1 10.1.1.2 internal lan

/etc/rc.conf
ifconfig_fxp0="inet 64.140.xxx.xxx netmask 255.255.255.224"
ifconfig_xl0="inet 10.1.1.2  netmask 255.255.255.0"
defaultrouter="64.140. xxx.yyy"

/etc/ipnat.conf
map fxp0 10.1.1.0/24 -> 0.0.0.0/32 proxy port ftp ftp/tcp 
map fxp0 10.1.1.0/24 -> 0.0.0.0/32 portmap tcp/udp 1025:65000
map fxp0 10.1.1.0/24 -> 0.0.0.0/32

/etc/ipf.conf
pass out quick on fxp0 proto tcp all keep state
pass out quick on fxp0 proto udp all keep state
pass out quick on fxp0 proto icmp all keep state
pass in quick on fxp0 proto tcp from any to any port = 22
pass in quick on fxp0 proto tcp from any to any port = 25
pass in quick on fxp0 proto tcp from any to any port = 80
block in quick on fxp0 all


The problem is the fractional shadow T1 bandwidth is maxes out during
daytime usage...

I have a fast internet connection Comcast cable dhcp 3000Kb what I would
like to also use,
But need to keep the t1 too because its static ip needed for incoming mail
and web...

Any idea how this should done?

Maybe:
Install new nic with connection to Comcast cable modem..
ifconfig_newcard="DHCP"
defaultrouter="???" and this will update automatically when the 


Thanks,

Andras Kende