** $Filename: ARCNET.txt $ ** $Revision: 1.3 $ ** $Date: 92/01/10 15:18:56 $ S2WireType_Arcnet 7 ios2_DataLength: 506 byte MTU (because of the possibility of two byte Types). Packets of size 254, 255, or 256 bytes are padded to 257 bytes before transmition. Station Address: ARCNET hardware may have addresses set with jumpers, DIP switches or software. Different drivers may therefore behave differently with S2_CONFIGINTERFACE. Hardware addresses should be assigned by users from highest to lowest because there is some efficiency gained in the token passing scheme this way. For example, on a three node network, hardware numbers 254, 253 and 252 should be used rather than 1, 2 and 3. Raw reads and writes: Short Packets (1-253 bytes) Destination Address (1 byte) Source Address (1 byte) Count (256-N-Type length) (1 byte) Padding (to byte number Count) Type (1 or 2 bytes) Data (N bytes) Long Packets (257-506 bytes) Destination Address (1 byte) Source Address (1 byte) zero (1 byte) Count (512-N-Type length) (1 byte) Padding (to byte number Count) Type (1 or 2 bytes) Data (N bytes) Multicast: Not Supported Broadcast: Supported Promiscuous: Generally Not Supported Packet Type Numbers for ARCNET are assigned by: Datapoint Corporation Some Common Packet Type Numbers decimal hex description ------- --- ----------- 221 DD AppleTalk 240 F0 TCP/IP -- IP (RFC 1051) 241 F1 TCP/IP -- ARP (RFC 1051) 212 F0 TCP/IP IP (RFC 1201, proposed) 213 F1 TCP/IP -- ARP (RFC 1201, proposed) 214 D6 TCP/IP -- RARP (RFC 1201, proposed) 247 F7 Banyan Vines 250 FA Novell IPX