• 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.
IP protocol numbers
The currently assigned IP protocol numbers and references are published by the Internet
Assigned Numbers Authority (IANA) and can be found at:
http://www.iana.org/assignments/protocol-numbers
Example 3.17. Adding an IP Protocol Service
This example shows how to create an IP Protocol service for the Virtual Router Redundancy
Protocol (VRRP).
Command-Line Interface
gw-world:/> add Service ServiceIPProto VRRP IPProto=112
Chapter 3: Fundamentals
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