SSH connections difficulties

I'm using RED HAT 5.9 OS on my grid, having 3 machine: 1 Head node (known as ilmn-qm.ilmn) and 2 compute nodes (aka compute-00-00 and compute-00-01). **Problem is that i cant use SSH from either one of the compute nodes units.** I tried: 1) SSH FROM and TO head node works perfectly. 2) SSH from head node to compute nodes works. 3) vise versa SSH from compute nodes to head nodes work as well. 4) Head node define as gateway: [root@compute-00-01 ~]# route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 172.20.22.0 * 255.255.255.0 U 0 0 0 eth1 172.20.20.0 * 255.255.255.0 U 0 0 0 eth0 169.254.0.0 * 255.255.0.0 U 0 0 0 eth0 default ilmn-qm.ilmn 0.0.0.0 UG 0 0 0 eth0 5) I've checked that ipv4 forwarding is enabled on the Head node cat /etc/sysctl.conf # 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 = 1 # 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 # 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 and yet any ssh attempt ends up with: ssh: connect to host 132.68.107.69 port 22: Connection timed out from Head node: root@ilmn-qm ~ # ip a show 1: lo: mtu 16436 qdisc noqueue link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: mtu 1500 qdisc pfifo_fast qlen 1000 link/ether f0:4d:a2:0b:2d:b9 brd ff:ff:ff:ff:ff:ff inet 132.68.106.1/28 brd 132.68.106.15 scope global eth0 inet6 fe80::f24d:a2ff:fe0b:2db9/64 scope link valid_lft forever preferred_lft forever 3: eth1: mtu 1500 qdisc pfifo_fast qlen 1000 link/ether f0:4d:a2:0b:2d:bb brd ff:ff:ff:ff:ff:ff inet 172.20.20.5/24 brd 172.20.20.255 scope global eth1 inet6 fe80::f24d:a2ff:fe0b:2dbb/64 scope link valid_lft forever preferred_lft forever 4: eth2: mtu 1500 qdisc pfifo_fast qlen 1000 link/ether f0:4d:a2:0b:2d:bd brd ff:ff:ff:ff:ff:ff inet 172.20.21.2/24 brd 172.20.21.255 scope global eth2 inet6 fe80::f24d:a2ff:fe0b:2dbd/64 scope link valid_lft forever preferred_lft forever 5: eth3: mtu 1500 qdisc noop qlen 1000 link/ether f0:4d:a2:0b:2d:bf brd ff:ff:ff:ff:ff:ff 6: sit0: mtu 1480 qdisc noop link/sit 0.0.0.0 brd 0.0.0.0 root@ilmn-qm ~ # ip route show 132.68.106.0/28 dev eth0 proto kernel scope link src 132.68.106.1 172.20.21.0/24 dev eth2 proto kernel scope link src 172.20.21.2 172.20.20.0/24 dev eth1 proto kernel scope link src 172.20.20.5 169.254.0.0/16 dev eth2 scope link default via 132.68.106.14 dev eth0 from compute-00-00: [root@compute-00-00 ~]# ip a show 1: lo: mtu 16436 qdisc noqueue link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: mtu 1500 qdisc pfifo_fast qlen 1000 link/ether f0:4d:a2:0b:2d:c2 brd ff:ff:ff:ff:ff:ff inet 172.20.20.6/24 brd 172.20.20.255 scope global eth0 inet6 fe80::f24d:a2ff:fe0b:2dc2/64 scope link valid_lft forever preferred_lft forever 3: eth1: mtu 1500 qdisc pfifo_fast qlen 1000 link/ether f0:4d:a2:0b:2d:c4 brd ff:ff:ff:ff:ff:ff inet 172.20.22.6/24 brd 172.20.22.255 scope global eth1 4: eth2: mtu 1500 qdisc pfifo_fast qlen 1000 link/ether f0:4d:a2:0b:2d:c6 brd ff:ff:ff:ff:ff:ff 5: eth3: mtu 1500 qdisc pfifo_fast qlen 1000 link/ether f0:4d:a2:0b:2d:c8 brd ff:ff:ff:ff:ff:ff 6: sit0: mtu 1480 qdisc noop link/sit 0.0.0.0 brd 0.0.0.0 [root@compute-00-00 ~]# ip route show 172.20.22.0/24 dev eth1 proto kernel scope link src 172.20.22.6 172.20.20.0/24 dev eth0 proto kernel scope link src 172.20.20.6 169.254.0.0/16 dev eth1 scope link default via 172.20.20.5 dev eth0 from compute-00-01: [root@compute-00-01 ~]# ip a show 1: lo: mtu 16436 qdisc noqueue link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 84:2b:2b:f9:9e:11 brd ff:ff:ff:ff:ff:ff inet 172.20.20.7/24 brd 172.20.20.255 scope global eth0 inet6 fe80::862b:2bff:fef9:9e11/64 scope link valid_lft forever preferred_lft forever 3: eth1: mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 84:2b:2b:f9:9e:13 brd ff:ff:ff:ff:ff:ff inet 172.20.22.7/24 brd 172.20.22.255 scope global eth1 4: eth2: mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 84:2b:2b:f9:9e:15 brd ff:ff:ff:ff:ff:ff 5: eth3: mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 84:2b:2b:f9:9e:17 brd ff:ff:ff:ff:ff:ff 6: sit0: mtu 1480 qdisc noop link/sit 0.0.0.0 brd 0.0.0.0 [root@compute-00-01 ~]# ip route show 172.20.22.0/24 dev eth1 proto kernel scope link src 172.20.22.7 172.20.20.0/24 dev eth0 proto kernel scope link src 172.20.20.7 169.254.0.0/16 dev eth0 scope link default via 172.20.20.5 dev eth0