Unit 3
1,Compare ICMP AND DHCP
ICMP (Internet Control Message Protocol) and DHCP (Dynamic Host Configuration Protocol):
ICMP (Internet Control Message Protocol):
1. **Purpose**: ICMP is a network-layer protocol used to report errors and exchange control
messages between network devices.
2. **Functions**:
- **Error Reporting**: ICMP reports errors in packet delivery, such as "Destination
Unreachable" or "Time Exceeded".
- **Network Testing**: Tools like Ping (ICMP Echo Request/Reply) and Traceroute (ICMP Time
Exceeded) use ICMP to diagnose network connectivity and routing issues.
- **Router Information**: ICMP messages like Router Advertisement and Router Solicitation
assist in discovering routers on a network.
3. **Message Types**:
- **Echo Request/Reply**: Used by Ping to test reachability and round-trip time.
- **Destination Unreachable**: Indicates that a destination is unreachable for various
reasons.
- **Time Exceeded**: Indicates that the TTL (Time-to-Live) field has expired.
- **Parameter Problem**: Reports errors in IP headers.
- **Redirect**: Informs a host of a better next-hop router for a particular destination.
+-----------+
| Source |
+-----------+
, |
| IP Network
|
+-----------+
| Router |
+-----------+
|
| IP Network
|
+-----------+
| Destination |
+-----------+
- **Router Advertisement/ Solicitation**: Used by routers to announce their presence and
by hosts to discover routers on a network.
DHCP (Dynamic Host Configuration Protocol):
1. **Purpose**: DHCP is a client/server protocol used to dynamically assign IP addresses and
other network configuration parameters to devices on a network.
2. **Functions**:
- **IP Address Assignment**: DHCP servers assign IP addresses dynamically to DHCP clients
(devices requesting network connectivity).
- **Configuration Parameters**: DHCP also provides subnet mask, default gateway, DNS
server, and other network configuration details to clients.