The Serial Line Address Resolution Protocol (SLARP) is a protocol used primarily for address resolution over serial lines. It helps devices connected via serial communication to discover each other's network addresses.
Understanding SLARP
SLARP is designed for environments where traditional methods of address resolution, such as ARP (Address Resolution Protocol) over Ethernet, are not suitable. This is often the case in serial communication setups where a point-to-point connection exists.
Key Features
- Purpose: To resolve network addresses in serial line environments.
- Frame Type: SLARP frames are identified by the cHDLC protocol code value of
0x8035. - Frame Variants: SLARP utilizes three primary frame types:
- Address Request (0x00): A device sends this to discover the network address of another device.
- Address Reply (0x01): A device responds with this to communicate its network address after receiving an address request.
- Keep-Alive (0x02): Devices use this to ensure the connection is active and maintained.
How SLARP Works
- Request Phase: A device broadcasts an address request.
- Response Phase: The targeted device responds with its corresponding network address.
- Maintenance Phase: Keep-alive frames are exchanged to maintain the active connection and periodically re-verify device status.
Practical Application
SLARP is typically found in scenarios involving:
- Legacy Systems: Older hardware that uses serial connections.
- Embedded Systems: Small devices with limited network capabilities.
- Point-to-Point Connections: Direct communication between two devices.
Advantages of SLARP
- Simplicity: SLARP is easy to implement and understand.
- Efficiency: It works well in resource-constrained environments.
- Low Overhead: The protocol adds minimal overhead to serial line communication.
Disadvantages of SLARP
- Limited Scope: It's specific to serial line environments.
- Not Universal: Not used in mainstream network environments.
| SLARP Frame Type | Value | Description |
|---|---|---|
| Address Request | 0x00 | Used by a device to request the network address of another device. |
| Address Reply | 0x01 | Used by a device to respond with its network address to an address request. |
| Keep-Alive | 0x02 | Used to maintain the connection and monitor device status. |
In summary, the Serial Line Address Resolution Protocol (SLARP) is a protocol tailored to handle network address resolution in serial line environments, distinguished by its cHDLC code of 0x8035 and the utilization of address requests, replies, and keep-alive frames.
