請大家幫幫忙,網路的問題

gateway_enable="YES"
kern_securelevel_enable="NO"
moused_enable="NO"
moused_port="/dev/psm0"
moused_type="auto"
nfs_reserved_port_only="YES"
sendmail_enable="YES"
sshd_enable="YES"
usbd_enable="YES"
# -- sysinstall generated deltas -- # Fri Jul 4 18:05:21 2003
ifconfig_em0="inet 192.168.0.254 netmask 255.255.255.0"
ifconfig_rl1="inet 210.70.157.132 netmask 255.255.255.0"
ifconfig_rl0="inet 61.62.55.253 netmask 255.255.255.0"
defaultrouter="210.70.157.254"
hostname="dns1a.cvig.org"

# -- natd setting -- #
#natd_program="/sbin/natd" # path to natd, if you want a different one.
#natd_enable="YES" # Enable natd (if firewall_enable == YES).
#natd_interface="rl1" # Public interface or IPaddress to use.
#natd_flags="-dynamic" # Additional flags for natd.
# -- firewall setting -- #
firewall_enable="YES" # Set to YES to enable firewall functionality
firewall_script="/etc/rc.firewall" # Which script to run to set up the firewall
firewall_type="OPEN" # Firewall type (see /etc/rc.firewall)
firewall_quiet="NO" # Set to YES to suppress rule display
firewall_logging="NO" # Set to YES to enable events logging
firewall_flags="" # Flags passed to ipfw when type is a file
# named. It may be possible to run named in a sandbox, man security for
named_enable="YES" # Run named, the DNS server (or NO).
named_program="/usr/sbin/named" # path to named, if you want a different one.
#named_flags="-u bind -g bind" # Flags for named

router_enable="NO"
==================================================================
以上是我的設定檔....
我的問題是....我有三張網卡
em0是內部的dhcp server之前都是分完IP後從rl0(這個是固定IP的sonet)這張網卡出去
現在是因為so-net不用了....所以要把dhcp server這張網卡改從rl1出去上網....
可是我改來改去都沒辦法上網....
請問一下大大....我要怎麼樣才能讓em0分出去的電腦上網