RTKernel-32

RTFiles-32

RTIP-32

RTIP-32 Programming Manual

RTIP-32 Reference Manual

RTIP-32 Configuration

Socket API

Simplified Networking API

Extended RTIP-32 API

Function vf_init

Function xn_add_dns_server

Function xn_add_host_table_entry

Function xn_clear_host_cache

Function xn_delete_host_table_entry

Function xn_get_domain_name

Function xn_has_dns

Function xn_set_domain_name

Function xn_set_server_list

Function xn_name2ip_addr

Function xn_abort

Function xn_arp_send

Function xn_attach

Function xn_bootp_res

Function xn_bootp

Function xn_debug_error

Function xn_getlasterror

Function xn_geterror_string

Function xn_interface_close

Function xn_interface_info

Function xn_interface_mcast

Function xn_interface_open

Function xn_interface_open_config

Function xn_interface_opt

Function xn_interface_ethernet_statistics

Function xn_interface_statistics

Function xn_ip_set_option

Function xn_ping

Function xn_pkt_data_max

Function xn_rarp

Function xn_rt_add

Function xn_rt_cycle_gw

Function xn_rt_del

Function xn_rt_replace

Function xn_rtip_exit

Function xn_rtip_init

Function xn_rtip_restart

Function xn_set_ip

Function xn_tcp_is_connect

Function xn_tcp_is_read

Function xn_tcp_is_write

Function xn_wait_tcp_output

Function xn_autoanswer

Function xn_autologin

Function xn_hangup

Function xn_scriptlogin

Function xn_autoip

Function xn_ioacc_init

Function xn_nat_init

Function xn_arp_add

Function xn_arp_del

Function xn_arp_remote

Function xn_arp_cache_lookup

Function xn_send_ethernet_frame

Function xn_callbacks

Function cb_wr_screen_string_fnc

Function cb_rs232_connection_lost_fnc

Function cb_error_report_fnc

Function cb_raw_mode_in_char_fnc

Function cb_autoip_new_ip_fnc

Function cb_autoip_no_ip_fnc

Function cb_packetin_isr

Function cb_packetin_task

Function cb_packetout

Function xn_arp_remote

xn_arp_remote sends out an ARP request to resolve an IP address:

int xn_arp_remote(int * iface,  BYTE * ipn, long timeout);

Parameters

iface

Pointer to an integer which holds the interface number on which the request is to be sent or was sent. When the interface is set to -1 before this function is called, the IP stack will select an appropriate interface based on parameter *ipn and then assign that interface number to *iface. This parameter is optional and may be set to NULL.

ipn

Pointer to the IP address in network byte order to be resolved.

timeout

Timeout in seconds to wait for an ARP reply. If this parameter is set to 0, the function does not wait and will not return a timeout error. ARP requests sent internally by RTIP-32 have a timeout of CFG_ARPC_REQ_TIMEOUT (1 second by default).

return value

Returns 0 if successful, otherwise SOCKET_ERROR. If an error occurred, call xn_getlasterror and xn_geterror_string to return the error value. Section Error Codes further describes each error.

This function can be used to either create or refresh an ARP cache entry. It can also be used to check if a particular IP address on the local LAN segment is currently reachable. If parameter timeout is greater zero and the function returns success, the ARP cache entry can be looked up using xn_arp_cache_lookup.

Please note that this function should not be called too frequently to avoid flooding the LAN with ARP requests. ARP cache entries have a configurable live-time (see CFG_ARP_TIMEOUT, default 10 minutes). xn_arp_remote should be called to refresh an ARP cache entry only when it is about to expire. The remaining live-time can be queried with function xn_arp_cache_lookup.

Left Extended RTIP-32 API

Function xn_arp_del

Down Function xn_arp_cache_lookup