SLP
Service Location Protocol (SLP) is an Internet standard network protocol that provides a framework to allow networking applications to discover the existence, location, and configuration of networked services in enterprise networks, such as printers, Web servers, fax machines, video cameras, file systems, backup devices (tape drives), databases, directories, mail servers, and calendars.
In order to locate services on the network, users of network applications are required to supply the host name or network address of the device that supplies a desired service. However, SLP eliminates the need for a user to know the name of a network host supporting a service. Rather, the user only needs to supply the desired type of service and set of attributes or keywords, which describe the service.
Based on that description, SLP also resolves the network address of the service of the user. Administrators do not need to help clients find new services or to remove services when they are no longer available. SLP uses multicasting and can work over subnet boundaries.
Configuring SLP
You can configure SLP protocol settings through SyncThru Web Service. Select Network Settings Æ SLP.
•SLP Protocol: You can enable or disable SLP.
•Port Number: The port number is fixed to 427.
•Scope 1 ~ 3: A scope is a set of services and a string used to group resources by location, network, or administrative category. Each scope should not be more than 32 characters.
•Message Type: You can select the outgoing SLP message type sent to network devices. The default value is Multicast.
•Multi Cast Radius: You can specify the maximum number
of subnets that SLP multicasts can travel across. This value is also called the “hop count” or
•Registration Lifetime: You can define the time in seconds before the Server Agents registration expires.
•Multicast Address: The Multicast Address value is fixed to 239.255.255.253, 224.0.1.127.
Using SLP
Once SLP enabled is checked, the network print server works as a Service Agent and the User Agent, for example, SyncThru Admin Service, searches for the network print server by SLP Protocol.
3.2
TCP/IP environment
Dynamic DNS (DDNS)
DNS (Domain Name System) is used for registration of domain names and provides Host names to an IP address resolution service. For printer devices, DNS may be utilised for printer domain name registration, so that print server clients may refer to the printer by its host name rather than by its IP address. Even though a printer’s IP address is changed, all clients can operate this printer without reconfiguration. Addressing to a printer device by IP address is not convenient and may often go stale if an IP address to a device is assigned dynamically via a DHCP server. If the DHCP server can provide information about a printer’s changing IP address to the DNS server automatically, user convenience is increased. The printer’s name will be used as its DNS name.
Configuring DDNS
1Let the DHCP server provide updated information to the DNS server.
2Configure the same DDNS domain through SyncThru Web Service as entered in the DNS server.
If you connect your network printer via a web browser, you can enable this by selecting Network Setting Æ TCP/IP
Æ Dynamic DNS Registration.
3Set the IP assignment method of your network print server to DHCP and reboot the printer.
The DNS server will update its database and users can use the printer’s name instead of its IP address.
WINS
Before Dynamic DNS was defined, DNS could only be updated manually when DHCP servers automatically provided (or removed) IP addresses. As a result, DNS servers often contained obsolete listings. In response, Microsoft developed Windows Internet Name Service (WINS) to solve this problem for NetBIOS names.
Microsoft now recommends moving to Dynamic DNS and away from WINS. However, many customers including Microsoft maintain WINS systems and need devices to interoperate with WINS. So devices must, at least for now, support WINS interoperability to allow for dynamic NetBIOS name to IP address registration and resolution.
WINS provides a distributed database for registering and querying dynamic NetBIOS names to IP address mapping in a routed network environment. This is the best choice for NetBIOS name resolution in such a routed network because it is designed to solve the problems that occur with name resolution in complex Internet networks.
