Wednesday, October 19, 2011

"No route to host" error

Can't believe another day is over. Learn so much about installation of Red Hat.

I had one windows desktop and a windows laptop given to me from work, so I decided to format my desktop to linux. Nice idea isn't it. Got the CD from one colleague and I am on my way to install RH for the first time. I have 10 years of experience installing windows :D how hard it can be, correct?

I opted for GUI option and on my way hitting next next next. Installation complete bingo!!!!. It was easy. Next I wanted to know the IP of my box. boom! ifconfig gave me 127.0.0.1. The moment I saw local ip, I knew I am in trouble.
Realized that my ethernet device is all disabled and just activating them solved this tiny issue of mine. Used "/usr/bin/neat" command to figure it out.

Now I got IP and being able to ping to server from my laptop. It's a brand new box so thought, let me go ahead and install my tools like java, jetty etc...
Downloaded the rpms and wanted to ftp to new box and fired putty. Boom! started getting another error. "No route to host".
Googles and found very nice article to help me. (http://nixcraft.com/linux-hardware/6366-no-route-host.html). I am pasting the content.

----------------------------------------------
I too have a problem with putty connect to my
VM Ware. And what I do :

1. Check ip`s and ports in my CentOS (VM Ware) and my PuTTY.

Result : no mistakes.

2. Check the state sshd in my CentOS (VM Ware):

[root@localhost ~]# /etc/init.d/sshd status
sshd (pid 3940 3936) is running...
[root@localhost ~]#

Result : sshd is running.

3. Check the state a port on CentOs for connection through ssh:

[root@localhost ~]# netstat -a | grep ssh
tcp 0 0 *:ssh *:* LISTEN
[root@localhost ~]#

or

[root@localhost ~]# cat /etc/services | grep ssh
ssh 22/tcp # SSH Remote Login Protocol
ssh 22/udp # SSH Remote Login Protocol
[root@localhost ~]# netstat -an | grep 22
tcp 0 0 :::22 :::* LISTEN
[root@localhost ~]#


Result: all is normal.

4. Check configuration my iptables:

[root@localhost ~]# /sbin/iptables -L -n
Chain INPUT (policy ACCEPT)
target prot opt source destination
RH-Firewall-1-INPUT all -- 0.0.0.0/0 0.0.0.0/0

Chain FORWARD (policy ACCEPT)
target prot opt source destination
RH-Firewall-1-INPUT all -- 0.0.0.0/0 0.0.0.0/0

Chain OUTPUT (policy ACCEPT)
target prot opt source destination

Chain RH-Firewall-1-INPUT (2 references)
target prot opt source destination
ACCEPT all -- 0.0.0.0/0 0.0.0.0/0
ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0 icmp type 255
ACCEPT esp -- 0.0.0.0/0 0.0.0.0/0
ACCEPT ah -- 0.0.0.0/0 0.0.0.0/0
ACCEPT udp -- 0.0.0.0/0 224.0.0.251 udp dpt:5353
ACCEPT udp -- 0.0.0.0/0 0.0.0.0/0 udp dpt:631
ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
[root@localhost ~]#

Result: God dammed!! No rule for port 22! -> port 22 - forbidden!

4. Add rule for port 22 to my iptables:
Just insert it line by means of your favourite editor
in /etc/sysconfig/iptables:
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT

before:

-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
COMMIT

Warning: your chaine name may be enother, because you have enother Linux. Curent chaine name you can see through /sbin/iptables -L -n (see above).

5. Check /etc/sysconfig/iptables:

[root@localhost ~]# cat /etc/sysconfig/iptables
# Firewall configuration written by system-config-securitylevel
# Manual customization of this file is not recommended.
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:RH-Firewall-1-INPUT - [0:0]
-A INPUT -j RH-Firewall-1-INPUT
-A FORWARD -j RH-Firewall-1-INPUT
-A RH-Firewall-1-INPUT -i lo -j ACCEPT
-A RH-Firewall-1-INPUT -p icmp --icmp-type any -j ACCEPT
-A RH-Firewall-1-INPUT -p 50 -j ACCEPT
-A RH-Firewall-1-INPUT -p 51 -j ACCEPT
-A RH-Firewall-1-INPUT -p udp --dport 5353 -d 224.0.0.251 -j ACCEPT
-A RH-Firewall-1-INPUT -p udp -m udp --dport 631 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
COMMIT
[root@localhost ~]#

6. Reboot you Linux and enjoy PuTTY
[root@localhost ~]# reboot
-------------------------------

Life is good again.

Manisha

No comments:

Post a Comment