1.2.4.5.2 Internet Protocol (IP) Configurations

IPv4 Specific User Configurations

• Enable Console Commands:

  • Enable the IPv4 TCP/IP Console Commands
  • Default value: false
  • Symbol: TCPIP_IPV4_COMMANDS_ENABLE, TCPIP_IPV4_COMMANDS

• Number of ARP Requests IPv4 can queue:

  • The number of entries that IPv4 can queue up for ARP resolution.
  • Usually it should be <= the number of total ARP cache entries for all interfaces
  • Default value: 10
  • Symbol TCPIP_IPV4_ARP_QUEUE_SLOTS, TCPIP_IPV4_ARP_SLOTS

• Enable IPv4 Fragmentation Support:

  • If 1, enable IPv4 fragmentation processing, RX + TX
  • If 0 (default), IPv4 fragmentation not supported
  • Default value: false
  • Symbol TCPIP_IPV4_FRAGMENTATION

• Initial fragment timeout (in sec):

  • Initial fragment timeout
  • Timer Lower Bound (RFC 791)
  • The RFC states this value to be 15 seconds
  • Value is in seconds
  • Default value: 15
  • Symbol TCPIP_IPV4_FRAGMENT_TIMEOUT

• Maximum number of fragmented streams:

  • Upper limit for the number of fragmented streams that could be handled simultaneously
  • Default value: 3
  • Symbol TCPIP_IPV4_FRAGMENT_MAX_STREAMS

• Maximum number of fragments:

  • Upper limit for the number of fragments in a fragmented stream
  • This also imposes a limit on how large a packet could be depending on the MTU and fragmentations that occur
  • If more fragments received for a certain stream, the stream will be discarded
  • Default value: 4
  • Symbol TCPIP_IPV4_FRAGMENT_MAX_NUMBER

• Enable External Packet Processing:

  • This setting enables/disables the processing of the RX packets by an external handler
  • The user of the IPv4 can register an external function to process the incoming packets
  • If true, the functionality is built in and could be used by the application
  • If false, the functionality does not exist and the generated code is slightly smaller
  • Default value: false
  • Symbol TCPIP_IPV4_EXTERN_PACKET_PROCESS

• IPv4 Fragmentation Task Rate (in msec):

  • IPv4 task processing rate, in milliseconds.
  • The IPv4 module will process a timer event with this rate for maintaining its own queues, processing timeouts, etc.
  • The lower the rate (higher the frequency) the higher the module priority and higher module performance can be obtained
  • The default value is around 30 milliseconds.
  • The value cannot be lower than the TCPIP_STACK_TICK_RATE.
  • Value is in milliseconds
  • Default value: 37
  • Symbol TCPIP_IPV4_TASK_TICK_RATE

• Enable IPv4 Forwarding Support:

  • Builds the IPv4 module with forwarding support
  • Default value: false
  • Symbol TCPIP_IPV4_FORWARD, TCPIP_IPV4_FORWARDING_ENABLE

• Support Forwarding Table with ASCII strings:

  • The initialization forwarding table is in ASCII format, using strings
  • Default value: true
  • Symbol TCPIP_IPV4_FORWARD_ASCII_ENABLE, TCPIP_IPV4_FORWARDING_TABLE_ASCII

• Support Dynamic Forwarding Table Manipulation:

  • Enables run time API for forwarding tables manipulation
  • Certain API functions (TCPIP_IPV4_FwdTableAddAscii, TCPIP_IPV4_FwdTableRemoveAscii, ...) exists only if they are enabled
  • Default value: true
  • Symbol TCPIP_IPV4_FORWARD_DYN_ENABLE, TCPIP_IPV4_FORWARDING_DYNAMIC_API

• Enable Broadcast Traffic Forwarding:

  • Enable the forwarding of the broadcast packets
  • The default should be disabled
  • Default value: false
  • Symbol TCPIP_IPV4_FORWARD_BCAST_ENABLE

• Enable Forwarding Statistics:

  • Enable the IPv4 module to keep statistics counts
  • Default value: false
  • Symbol TCPIP_IPV4_FORWARD_STATS_ENABLE, TCPIP_IPV4_FORWARDING_STATS

• Forwarding TX Queue Slots:

  • The maximum number of broadcast and multicast packets that can be queued waiting for the output interface to transmit them.
  • This applies only for packets that have to be both forwarded and processed internally which is only broadcast or multicast
  • Adjust depending on your traffic
  • Note that if this limit is exceeded, the packets will not be forwarded but still processed internally
  • If 0, packets will not be forwarded, just processed internally.
  • Default value: 0
  • Symbol TCPIP_IPV4_FWD_QUEUE_SLOTS

• Forwarding Table Maximum Size:

  • The maximum number of entries in the forwarding table for each interface
  • Default value: 10
  • Symbol TCPIP_IPV4_FORWARD_TABLE_MAX_SIZE, TCPIP_IPV4_FORWARDING_TABLE_MAX_SIZE

• Use ASCII Init Forwarding Table:

  • Initialization table built with ASCII strings
  • Default value: true
  • Symbol TCPIP_IPV4_FORWARD_ASCII_SELECT

• Number of Entries in the Init Forwarding table:

  • Number of entries in the routing table as part of the initialization
  • Default value: none
  • Symbol TCPIP_IPV4_FORWARD_TABLE_CNT, TCPIP_IPV4_FORWARDING_TABLE_ENTRIES

• Network Destination Address:

  • Network destination address.
  • This address is used for matching the IPv4 packet destination address. For ex: "192.168.2.0"
  • Default value: "0.0.0.0"
  • Symbol TCPIP_IPV4_FWD_ENTRY_NET_ADD_IDX

• Network Mask:

  • Associated mask for this destination address. For ex: "255.255.255.0"
  • The value needs to be a valid network mask, with contiguous ones in its binary representation followed by contiguous zeros
  • Default value: "0.0.0.0"
  • Symbol TCPIP_IPV4_FWD_ENTRY_NET_MASK_IDX

• Gateway Destination Address:

  • Gateway destination address. For ex: "192.168.2.1"
  • Used as packets destination */
  • Default value: "0.0.0.0"
  • Symbol TCPIP_IPV4_FWD_ENTRY_GW_ADD_IDX

• Source Interface Name:

  • The name of the input interface that this entry applies to.
  • The forwarding tables are built per interface. For ex: "eth0", "wlan0", etc.
  • Default value: ""
  • Symbol TCPIP_IPV4_FWD_ENTRY_SRC_IF_NAME_IDX

• Destination Interface Name:

  • The name of the interface to go out on if this entry is selected. For ex: "eth0", "wlan0", etc.
  • Default value: ""
  • Symbol TCPIP_IPV4_FWD_ENTRY_DEST_IF_NAME_IDX

• Entry Metric Value:

  • The path efficiency. The smaller the value, the higher priority for the path.
  • Note that this value is useful only when there are multiple entries in the forwarding table that have the same number of mask bits set
  • Default value: 10
  • Symbol TCPIP_IPV4_FWD_ENTRY_METRIC_IDX