# Kernel sysctl configuration file for Red Hat Linux
#
# For binary values, 0 is disabled, 1 is enabled.  See sysctl(8) and
# sysctl.conf(5) for more details.

# Controls IP packet forwarding
net.ipv4.ip_forward = 0

# Controls source route verification
net.ipv4.conf.default.rp_filter = 1

# Do not accept source routing
net.ipv4.conf.default.accept_source_route = 0

# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0

# Controls whether core dumps will append the PID to the core filename.
# Useful for debugging multi-threaded applications.
kernel.core_uses_pid = 1

# Controls the use of TCP syncookies
net.ipv4.tcp_syncookies = 1

# Disable netfilter on bridges.
net.bridge.bridge-nf-call-ip6tables = 0
net.bridge.bridge-nf-call-iptables = 0
net.bridge.bridge-nf-call-arptables = 0

# Controls the maximum size of a message, in bytes
kernel.msgmnb = 65536

# Controls the default maxmimum size of a mesage queue
kernel.msgmax = 65536

# Controls the maximum shared segment size, in bytes
kernel.shmmax = 68719476736

# Controls the maximum number of shared memory segments, in pages
kernel.shmall = 4294967296
net.ipv4.ip_forward = 1

kol@kol /]$ ping 194.44.31.233
PING 194.44.31.233 (194.44.31.233) 56(84) bytes of data.
From 172.16.0.1 icmp_seq=1 Destination Host Prohibited
Fro
[m 172.16.0.1 icmp_seq=2 Destination Host Prohibited
--- 194.44.31.233 ping statistics ---
11 packets transmitted, 0 received, +11 errors, 100% packet loss, time 10833ms

[kol@kol /]$ ping 172.16.0.2
PING 172.16.0.2 (172.16.0.2) 56(84) bytes of data.
64 bytes from 172.16.0.2: icmp_seq=1 ttl=64 time=0.035 ms
64 bytes from 172.16.0.2: icmp_seq=2 ttl=64 time=0.023 ms
64 bytes from 172.16.0.2: icmp_seq=3 ttl=64 time=0.026 ms
^C
--- 172.16.0.2 ping statistics ---

PING 172.16.0.2 (172.16.0.2) 56(84) bytes of data.
64 bytes from 172.16.0.2: icmp_seq=1 ttl=64 time=0.035 ms
64 bytes from 172.16.0.2: icmp_seq=2 ttl=64 time=0.023 ms
64 bytes from 172.16.0.2: icmp_seq=3 ttl=64 time=0.026 ms
^C
3 packets transmitted, 3 received, 0% packet loss, time 2531ms
rtt min/avg/max/mdev = 0.023/0.028/0.035/0.005 ms
[kol@kol /]$ import -windows pol.png

# Firewall configuration written by system-config-firewall
# Manual customization of this file is not recommended.
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
COMMIT
*nat
-A POSTROUTING -o eth0 -j SNAT --to-source 194.44.31.237
#
COMMIT

root@pol pol]# service iptables restart
iptables: Сбрасываются правила межсетевого экрана:         [  OK  ]
iptables: Цепочкам назначается политика ACCEPT: nat filter [  OK  ]
iptables: Применяются правила межсетевого экрана: iptables-restore v1.4.7: no command specified
Error occurred at line: 17
Try `iptables-restore -h' or 'iptables-restore --help' for more information.
                                                           [СБОЙ ]
[root@pol pol]# mc

[root@pol sysconfig]#