ServiceLink Manual

Chapter 11. Conﬁguration

Remote hosts: As mentioned in the example earlier, you might want to point a hostname such as "www" to a remote system. While

"www" is created by default, you can create other names such as "home", "research", or any other appropriate name. In the form, you

simply enter the hostname, choose the domain, and enter the remote IP address.

Local hosts: This screen is a bit more complicated because you have more options. At a basic level, you can create a hostname in a

domain that points to another computer on your local network. To do this, just type in the hostname and enter the IP address in the

"Local IP" ﬁeld. For instance, you might want "research" to point to a computer system inside your network.

Where this gets complicated is when you want "research.mycompany.xxx" to be accessible both inside and outside your local

network. The challenge is that your local IP addresses are only accessible inside your network. For that reason, the target computer

system will need to have two network interface cards - one connected to the internal network and one connected to the external

network. You would then enter both IP addresses in this screen in the "Local IP" and "Global IP" ﬁelds. Note that this will only work

if you are a ServiceLink subscriber as the server alone does not update public DNS information.

Note: The "Ethernet address" ﬁeld when creating a hostname pointing to a local host is only used for reserving IP addresses

through DHCP as mentioned in the next section.

11.5.2. Reserving IP Addresses Through DHCP

Another task you can perform through this panel is to reserve an IP addresses for a given system based on its Ethernet address. For

instance, you might have another intranet web server within your company that you want to always have the same IP address. One

method of assigning that address is to manually conﬁgure the client machine to have a static IP address. The negative aspect of doing

this is that if you later want to change the network settings for that machine, you must manually go and conﬁgure that machine. An

example would be if one of your DNS servers changed its IP address. Additionally, you have to keep track somewhere of the fact that

you have assigned a speciﬁc IP address to that machine.

Rather than conﬁguring the machine manually, you can reserve an IP address from the DHCP server for that speciﬁc machine. This

has the same result as manually conﬁguring a static IP address, but offers two beneﬁts. First, you have one location to keep track of

all assigned static address. Second, through the DHCP server you will provide network settings. If you wish to change those settings,

the change can be simply done on your server. All DHCP clients will then receive those updated changes when they renew their

DHCP-provided addresses.

To reserve an IP address, you must ﬁrst determine the Ethernet address of your client system. Windows NT/2000 users can type the

command ipconfig /all. Windows 95/98 users can run the command winipcfg. Linux/UNIX users can type ifconfig.

Once you have determined the client’s Ethernet address, click on the link to create a new hostname for a local host. Add the

hostname of the target system, the Ethernet address along with the desired IP address into the web panel. From this point on speciﬁed

IP address will only be provided to a client system with the matching Ethernet address.

11.6. E-mail Retrieval

As shown below, this section of the server manager allows you to specify the protocol used to retrieve e-mail from your ISP and

conﬁgure other settings regarding the retrieval of e-mail.