Postfix is the default Mailer used in CentOS and Ubuntu. If you are using a residential Internet connection you will possibly need to use the Smarthost option in Postfix to deliver mail. If this is the case, here’s how to do it.
Edit /etc/postfix/main.cf and either edit or add the line:
relayhost = <smarthost>
Replacing with the server you will be using to deliver mail.
After this change, you’ll need to restart Postfix.
I have had my Mikrotik RB751G-2HnD in service for a few months now, and it’s been rocking along great. The cheap price had me a bit skeptical at first, but after seeing some of the reviews and the community around their devices, I was pretty sold. I purchased the first one to replace a Linksys E4500 wireless router after the Cisco cloud connect upgrade.
I am using the device as a simple home gateway router for my network, with many of the more advanced features disabled. I do have IPv6 enabled, using a tunnel provided by Hurricane Electric using their tunnel broker service, which has been very stable. The wireless works great with coverage area expanding beyond what the Linksys provided.
The device supports various VPN connections, but I have yet to test any of this. Other notable features include a wireless hotspot manager, VLANs and several routing protocols including BGP.
This post is being made for me personal notes. Maybe it will assist others at some point. I am always forgetting the various configuration files involved with setting up networking on a CentOS host. I have decided to document the process I go through each time to help me remember next time. Most of this information comes from various forums, CentOS documentation and the man pages.
Device specific information
A configuration file exists for each interface under /etc/sysconfig/network-scripts/. To change the configuration for eth0 we will need to edit /etc/sysconfig/network-scripts/ifcfg-eth0.
Edit the file to match to the following, leave any lines that are not listed below in place
To use a static IP address, edit the configuration file as noted below. Again, leave any lines already in the file not listed below in place. The NETWORK, NETMASK, and IPADDR should match your network settings.
If you’ve just installed Thunderbird on Fedora 13, you’ve probably noticed the Global Search bar is missing. At least, this is one of the first things I noticed. After using Thunderbird 3.x for sometime on Windows I’ve really come to love this feature.
It seems the default configuration on Fedora doesn’t enable this feature by default, however it is simple to get working. Go to the Preferences menu, Advanced section and check “Enable Global Search and Indexer”. After this, restart Thunderbird and it will begin indexing your mail. After which, the Global Search should work as expected.
Using telnet (or putty) it’s possible to some simple tests against a POP server. By no means exhaustive, it can give you insights in where to start troubleshooting.
First, using telnet and open a connection the remote POP server
telnet mailserver 110
Where mailserver is the mail server you want to connect to. Note that port 110 is the default port for POP, but could be different depending on your servers settings.
Once connected, use USER and PASS to login.
[root@ms1 ~] # telnet localhost 110
Connected to localhost.
Escape character is '^]'.
+OK POP3 localhost v2001.78rh server ready
+OK User name accepted, password please
+OK Mailbox open, 1 messages
Connection closed by foreign host.
Using ping6 and ip neigh it’s possible to discover other IPv6 hosts on your local network using the link-local addresses.
First, use ping6 to ping all hosts on the local network using the IPv6 link-local address
ping6 -c 2 -I eth0 ff02::1
Then, use ip neigh to show a list of IPv6 enable hosts on the local network