No remote access to Linux using ping or SSH, but Samba works

DFWT · 11-23-2007, 11:45 AM

Hi,

I have an openSUSE 10.2 (x64) installation and I want to access this machine from a Windows Vista client (x64 as well) in the same private LAN (subnet mask 255.255.255.0) using DHCP (router).

I can reach (ping) the Windows client and other network devices from within the Linux machine. But I cannot ping the Linux machine from the Windows client (using the IP address) nor can I connect to it using SSH or telnet via PuTTY. Pinging other network devices from the Windows client works fine.

Currently, the only way I can access the Linux machine from the Windows client is by using SMB/Samba (even using name resolution)!

This admittedly sounds like a firewall problem. But SUSE firewall is disabled and no additional firewall software is installed (at least none that I am aware of). Using nmap or netsat -ltnu confirms that ports 22 (SSH) and 23 (telnet) are indeed open and listening.

Disabling the firewall on the Windows client did have no effect.

I should add that the Linux machine runs inside a virtual machine on the Windows host using VMWare Workstation 6.0 (with bridged networking). I do not believe that this contributes to the problem because I have successfully worked with similar environments in the past.

I would appreciate any suggestions on where I might start looking for a solution.

GushpinBob · 11-23-2007, 12:35 PM

Stupid but simple question: is sshd installed and running on the linux system? If it is, can you login locally and try connecting to ssh via a loopback device (in other words, typing ssh username@127.0.0.1 or ssh username@localhost)?

DFWT · 11-23-2007, 12:55 PM

Thanks for your suggestion. But sshd is running (it is started in run levels 3 and 5). I can connect to my machine locally using ssh without problems.

armandrix · 11-23-2007, 01:22 PM

Hi there...
I think you can start trying to see where connection get lost... vmware gives your virtual opensuse an ip address, from the host (win box) you can ping the guest (suse)?
Maybe it can be an issue between the host machine nic and the virtual nic, windows is redirecting outside packets to virtual machine??
It can be a start

DFWT · 11-23-2007, 01:58 PM

Hi,

the virtual machine gets its own IP address from the DHCP server (which is a router on my network). I confirmed with ifconfig that the (virtual) ethernet device (eth0) has a valid IP address from the DHCP server's IP pool. Unfortunately, I am unable to ping the virtual machine from the windows host using that address. But connecting to the samba shares using that IP address works fine.

armandrix · 11-23-2007, 03:05 PM

u-hu .. really strange this situation...

Try see if firewall on suse are really off. type in a root terminal --> # iptables -F ..this kills all firewall rules.
Also you can see the rules for ping replies: # cat /proc/sys/net/ipv4/icmp_echo_ignore_all this command must reply 0.
there is other for broadcast: cat /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts ...0 means ok.. 1 means don't reply.

try set both icmp as 0 for sure. After this you can be sure the guest suse is opened. Afterwards try to see vmware host setup in Edit > Virtual Network Settings. I cannot mind other things about suse... about windows cannot even imagine.. sorry

DFWT · 11-23-2007, 03:22 PM

Hi,

thanks for your effort. Unfortunately, performing these steps did not make any difference.

DFWT · 11-25-2007, 09:34 AM

Hi,

I found out that the problems are most likely due to caching issues either with the Windows client or (more likely) with the router (DHCP server).

I assigned a new IP pool to the DHCP server to enforce new IP addresses for all network clients. This solved the problem. Ping, SSH, HTTP, SMB ... all is working fine now.

Thanks to all those who helped in finding a solution.