Difference between revisions of "IP linux route manipulation"
From Teknologisk videncenter
m (Created page with "=Example= <source lang=bash> #!/bin/sh # #Enable Routing echo "1" > /proc/sys/net/ipv4/ip_forward #Flush Route table 4 and remove mark 4 ip route flush table 4 ip rule del fwm...") |
m (→Example) |
||
| Line 31: | Line 31: | ||
iptables -t nat -A POSTROUTING -s 172.21.0.0/16 -d 0/0 -j SNAT --to 204.0.0.34 | iptables -t nat -A POSTROUTING -s 172.21.0.0/16 -d 0/0 -j SNAT --to 204.0.0.34 | ||
iptables -t nat -A POSTROUTING -s 172.22.0.0/16 -d 0/0 -j SNAT --to 204.0.0.34 | iptables -t nat -A POSTROUTING -s 172.22.0.0/16 -d 0/0 -j SNAT --to 204.0.0.34 | ||
| + | </source> | ||
| + | ==Showing the Route table== | ||
| + | Example show below has nothing to do with example above. | ||
| + | <source lang=cli> | ||
| + | heth@mars2:~$ ip route show table main | ||
| + | 192.168.139.0/24 dev eth0 proto kernel scope link src 192.168.139.50 | ||
| + | default via 192.168.139.1 dev eth0 metric 100 | ||
| + | heth@mars2:~$ ip route show table 4 | ||
| + | Kernel IP routing table | ||
| + | Destination Gateway Genmask Flags Metric Ref Use Iface | ||
| + | 192.168.140.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 | ||
| + | 0.0.0.0 192.168.140.1 0.0.0.0 UG 100 0 0 eth1 | ||
</source> | </source> | ||
[[Category:Linux]][[Category:Network]] | [[Category:Linux]][[Category:Network]] | ||
Latest revision as of 14:57, 9 January 2012
Example
#!/bin/sh
#
#Enable Routing
echo "1" > /proc/sys/net/ipv4/ip_forward
#Flush Route table 4 and remove mark 4
ip route flush table 4
ip rule del fwmark 4 table 4
#Flush iptables Rules
iptables -F -t nat
iptables -F -t mangle
#Add static routes to route table 4
ip route add table 4 204.0.0.32/28 dev eth1 scope link
ip route add table 4 172.21.0.0/16 dev eth2 scope link
ip route add table 4 default via 204.0.0.33
ip route add table 4 172.22.0.0/16 dev eth2 via 172.21.0.2
#Mark packets coming from 172.21/16 and 172.22/16 with 4
iptables -t mangle -A PREROUTING -s 172.21.0.0/16 -d 0/0 -j MARK --set-mark 4
iptables -t mangle -A PREROUTING -s 172.22.0.0/16 -d 0/0 -j MARK --set-mark 4
#Add mark 4 to route table 4
ip rule add fwmark 4 table 4
#Source Nat trafix from 172.21/16 and 172.22/16 to 204.0.0.34 (Source address changed in packets)
iptables -t nat -A POSTROUTING -s 172.21.0.0/16 -d 0/0 -j SNAT --to 204.0.0.34
iptables -t nat -A POSTROUTING -s 172.22.0.0/16 -d 0/0 -j SNAT --to 204.0.0.34
Showing the Route table
Example show below has nothing to do with example above.
heth@mars2:~$ ip route show table main
192.168.139.0/24 dev eth0 proto kernel scope link src 192.168.139.50
default via 192.168.139.1 dev eth0 metric 100
heth@mars2:~$ ip route show table 4
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.140.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
0.0.0.0 192.168.140.1 0.0.0.0 UG 100 0 0 eth1