>Покажите вывод ifconfig eth0 и free #XX.XX.XX. - сеть с реальными адресами
server# ifconfig eth1 (сейчас сеть на eth1)
eth1 Link encap:Ethernet HWaddr 00:16:76:21:d2:ce
inet addr:XX.XX.XX.2 Bcast:XX.XX.XX.15 Mask:255.255.255.240
inet6 addr: fe80::216:76ff:fe21:d2ce/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:5996279 errors:0 dropped:0 overruns:0 frame:0
TX packets:3896858 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:2804054525 (2.6 GiB) TX bytes:2257225746 (2.1 GiB)
server# free
total used free shared buffers cached
Mem: 499212 492880 6332 0 1044 405124
-/+ buffers/cache: 86712 412500
Swap: 1461872 6584 1455288
server# cat /etc/network/interfaces
auto lo
iface lo inet loopback
# The primary network interface
auto eth0
auto eth1
iface eth1 inet static
address XX.XX.XX.2
netmask 255.255.255.240
network XX.XX.XX.0
broadcast XX.XX.XX.15
gateway XX.XX.XX.1
# dns-* options are implemented by the resolvconf package, if installed
dns-nameservers XX.XX.XX.20 XX.XX.XX.10
#самописный скрипт
pre-up /etc/iptables
server# cat /etc/iptables
IPTABLES=/sbin/iptables
$IPTABLES -F
$IPTABLES -t nat -F
$IPTABLES -P INPUT DROP
$IPTABLES -P OUTPUT ACCEPT
$IPTABLES -P FORWARD DROP
$IPTABLES -A INPUT -i lo -j ACCEPT
$IPTABLES -A INPUT -p tcp -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPTABLES -A INPUT -p udp -j ACCEPT
$IPTABLES -A INPUT -p icmp -j ACCEPT
$IPTABLES -A INPUT -s 192.168.88.0/24 -j ACCEPT