- machine1 IP: 172.30.11.119
- machine2 IP: 172.30.11.120
- machine3 IP: 172.30.11.121
- machine4 IP: 172.30.11.122
Note: These machines are connected to LAN.
I have configured the static IP for Ethernet interface of each machine as in above in /etc/network/interfaces file in order to persist the IP even after system reboot.
set the default gateway as 172.30.11.97 in machine4(in order to reach it from user desktop via putty connection manager)
allow-hotplug eth0 iface eth0 inet static address 172.30.11.122 netmask 255.255.255.0 gateway 172.30.11.97
But in other 3 machines I didn't set the default gateway as done for 122. Instead I tried policy routing in those 3 machines like below in the "interfaces" and "rt_table" file:
echo "1 policy_gw" >> /etc/iproute/rt_table In /etc/iproute/rt_table: 1 policy_gw In /etc/network/interfaces: allow-hotplug eth0 iface eth0 inet static address 172.30.11.121 netmask 255.255.255.0 post-up ip rule add dev eth0 table policy_gw post-up ip route add default via 172.30.11.97 dev etho src 172.30.11.121/24 table policy_gw Done like that for 120/119 machines.
now I can reach these machines directly via putty.
problem faced: I can able to ping every machine in this LAN from some other machine in the same LAN. But ssh is failing with the error"port 22:no route to host"
Suppose if I am in 121 machine: ssh 172.30.11.120 is throwing the above error.
default gateway is a cisco system router/switch.They are blocking ports for SSH,telnet protocols but not ICMP.
routing table of 122:
root@debian:~# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 172.30.11.97 0.0.0.0 UG 0 0 0 eth1 172.30.11.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
contents of ssh_config file:
Host * SendEnv LANG LC_* HashKnownHosts yes GSSAPIAuthentication yes GSSAPIDelegateCredentials no