Monday, 30 August 2010

SSH Tunnel Example

Tunnel ssh from Local Machine to Remote Machine
and from Remote Machine to a Local Machine on
Remote Machines network.

Local to remote machine with 5900 tunnel
ssh -L 5900:127.0.0.1:5900 -l username -p 22 theactualurl.net

Remote to machine on remote network with 5900 to 443 tunnel
sudo ssh -L 5900:127.0.0.1:443 -l username -p 22 remotemachine.local

This allowed one on the local machine to connect to a webserver using https on the remote machines network. The address on the local machine is https://localhost:5900 or https://127.0.0.1:5900 and the connection is tunnelled through port 5900 but the actual server uses port 443.

Wednesday, 25 August 2010

NIC IP Aliases

I needed to and Aliases for some IP addresses to the ethernet card on the Rocks Cluster to allow individual nodes to have their own public IP addresses.
I created a copy of the /etc/sysconfig/network-scripts/ifcfg-eth0 to ifcfg-eth0:0. This new file was edited with vi to contain

DEVICE=eth0:0
HWADDR=xx:xx:xx:xx:xx:xx
IPADDR=xxx.xxx.xxx.xx
NETMASK=255.255.255.0
BOOTPROTO=static
ONBOOT=yes


/sbin/service network restart to update the changes made.

/sbin/ifconfig shows the new configuration.

The change was tested by connecting the node switch to the public 211 subnet and the ip address could be pinged from the subnet showing that the changes were working.
Info On Binding IP Addresses