Amer Networks E5Web GUI - Manual (Page 149)

When a message type is selected but no code values are given then all codes for that type is
assumed.
ICMP Message Types
The message types that can be selected are as follows:
Echo Request Sent by PING to a destination in order to check connectivity.
Destination Unreachable The source is told that a problem has occurred when
delivering a packet. There are codes from 0 to 5 for this type:
• Code 0: Net Unreachable
• Code 1: Host Unreachable
• Code 2: Protocol Unreachable
• Code 3: Port Unreachable
• Code 4: Cannot Fragment
• Code 5: Source Route Failed
Redirect The source is told that there is a better route for a particular
packet. Codes assigned are as follows:
• Code 0: Redirect datagrams for the network
• Code 1: Redirect datagrams for the host
• Code 2: Redirect datagrams for the Type of Service and
the network
• Code 3: Redirect datagrams for the Type of Service and
the host
Parameter Problem Identifies an incorrect parameter on the datagram.
Echo Reply The reply from the destination which is sent as a result of the
Echo Request.
Source Quenching The source is sending data too fast for the receiver, the buffer
has filled up.
Time Exceeded The packet has been discarded as it has taken too long to be
delivered.
3.3.4. Custom IP Protocol Services
Services that run over IP and perform application/transport layer functions can be uniquely
identified by IP protocol numbers. IP can carry data for a number of different protocols. These
protocols are each identified by a unique IP protocol number specified in a field of the IP header.
For example, ICMP, IGMP and EGP have protocol numbers 1, 2 and 8 respectively.
Similar to the TCP/UDP port ranges described previously, a range of IP protocol numbers can be
used to specify multiple applications for one service. For example, specifying the range 1-4,7 will
match the protocols ICMP, IGMP, GGP, IP-in-IP and CBT.
Chapter 3: Fundamentals
149