# uip/uipopt.h File Reference

## Detailed Description

Configuration options for uIP.

Author:
  Adam Dunkels <adam@dunkels.com>

This file is used for tweaking various configuration options for uIP. You should make a copy of this file into one of your project's directories instead of editing this example "uipopt.h" file that comes with the uIP distribution.

Definition in file uipopt.h.

`#include "uip-conf.h"`

Go to the source code of this file.

## Static configuration options

These configuration options can be used for setting the IP address settings statically, but only if UIP_FIXEDADDR is set to 1. The configuration options for a specific node includes IP address, netmask and default router as well as the Ethernet address. The netmask, default router and Ethernet address are appliciable only if uIP should be run over Ethernet.

All of these should be changed to suit your project.

#define | UIP_FIXEDADDR
| Determines if uIP should use a fixed IP address or not.
#define | UIP_PINGADDRCONF
| Ping IP address asignment.
#define | UIP_FIXEDETHADDR
| Specifies if the uIP ARP module should be compiled with a fixed Ethernet MAC address or not.

## IP configuration options

#define | UIP_TTL 64
| The IP TTL (time to live) of IP packets sent by uIP.
#define | UIP_REASSEMBLY
| Turn on support for IP packet reassembly.
#define | UIP_REASS_MAXAGE 40
| The maximum time an IP fragment should wait in the reassembly buffer before it is dropped.

## UDP configuration options

#define | UIP_UDP
| Toggles wether UDP support should be compiled in or not.
#define | UIP_UDP_CHECKSUMS
| Toggles if UDP checksums should be used or not.
#define | UIP_UDP_CONNS
| The maximum amount of concurrent UDP connections.

## TCP configuration options

#define | UIP_ACTIVE_OPEN
| Determines if support for opening connections from uIP should be compiled in.
#define | UIP_CONNS
| The maximum number of simultaneously open TCP connections.
#define | UIP_LISTENPORTS
| The maximum number of simultaneously listening TCP ports.
#define | UIP_URGDATA
| Determines if support for TCP urgent data notification should be compiled in.
#define | UIP_RTO 3
| The initial retransmission timeout counted in timer pulses.
#define | UIP_MAXRTX 8
| The maximum number of times a segment should be retransmitted before the connection should be aborted.
#define | UIP_MAXSYNRTX 5
| The maximum number of times a SYN segment should be retransmitted before a connection request should be deemed to have been unsuccessful.
#define | UIP_TCP_MSS (UIP_BUFSIZE - UIP_LLH_LEN - UIP_TCPIP_HLEN)
| The TCP maximum segment size.
#define | UIP_RECEIVE_WINDOW
| The size of the advertised receiver's window.
#define | UIP_TIME_WAIT_TIMEOUT 120
| How long a connection should stay in the TIME_WAIT state.

## ARP configuration options

#define | UIP_ARPTAB_SIZE
| The size of the ARP table.
#define | UIP_ARP_MAXAGE 120
| The maxium age of ARP table entries measured in 10ths of seconds.

## General configuration options

#define | UIP_BUFSIZE
| The size of the uIP packet buffer.
#define | UIP_STATISTICS
| Determines if statistics support should be compiled in.
#define | UIP_LOGGING
| Determines if logging of certain events should be compiled in.
#define | UIP_BROADCAST
| Broadcast support.
#define | UIP_LLH_LEN
| The link level header length.
void | uip_log (char *msg)
| Print out a uIP log message.

## CPU architecture configuration

The CPU architecture configuration is where the endianess of the CPU on which uIP is to be run is specified. Most CPUs today are little endian, and the most notable exception are the Motorolas which are big endian. The BYTE_ORDER macro should be changed to reflect the CPU architecture on which uIP is to be run.
#define | UIP_BYTE_ORDER
| The byte order of the CPU architecture on which uIP is to be run.

## Defines

#define | UIP_LITTLE_ENDIAN 3412
#define | UIP_BIG_ENDIAN 1234