MACRAW for LLDP Packets?

Question

I am using an Arduino Ethernet which uses the W5100 ethernet controller. I want to send LLDP packets to do PoE+ power negotiation. One issue is that when I send LLDP to the PoE Switch, it reports CRC error. My question is whether or not the W5100 appends FCS to the MACRAW packets automatically, or do I have to add it to the payload myself? Here is my Arduino code: [code]#include // needed for Ethernet library communication with the W5100 (Arduino ver>0018) #include #include SOCKET s; // our socket that will be opened in RAW mode //LLDP packet byte buf = {0x01, 0x80, 0xc2, 0x00, 0x00, 0x0e, // lldp multicast mac address 0x90, 0xA2, 0xDA, 0x0F, 0x06, 0xD9, // arduino mac address 0x88, 0xCC, //ethertype 0x02, 0x07, //Chassis ID TLV (type 1, length 7) 0x04, // Chassis ID Subtype: Mac Address 0x90, 0xA2, 0xDA, 0x0F, 0x06, 0xD9, // arduino mac address 0x04, 0x04, // Port ID TLV (type 2, length 4) 0x05, // Interface Name 0x31, 0x2f, 0x37, // 1/7 0x06, 0x02, // Time to Live TLV (type 3, length 2) 0x00, 0x78, // 120 seconds //4-wire Power-via-MDI 0xfe, 0x05, // Optional TLV (type 127, length 5) 0x00, 0x01, 0x42, //Cisco OUI Identifier 0x01, //Cisco Subtype B00000001,/*PSE/PD Capabilities Reserved Bits 7:4 PSE Spare Pair Operational State: Bit3 0=Disable 1=Enable PD Spare Pais Desired State: Bit 2 0=Disable 1=Enable Spare Pair Detection/Classification required: Bit 1 0=Disable 1=Enable UPOE Supported: Bit 0 0=Disable 1=Enable */ // DTE Power via MDI TLV 0xfe, 0x0c, // Optional TLV (type 127, length 12) 0x00, 0x12, 0x0f, // 802 OUI 0x02, // 802.3 subtype B00000000, /* MDI Power Support Reserved: Bits 7:4 PSE Pair Control Ability Supported: Bit 3 0 = Not supported 1 = Supported PSE MDI Power State Enabled: Bit 2 0 = Disabled 1 = Enabled PSE MDI Power Support: Bit 1 0 = Not supported 1 = Supported Port Class: Bit 0 0 = PD 1 = PSE */ 0x01, // PSE Power Pair (pethPsePortPowerPairs IETF RFC 3621) 0x05, // Power Class (pethPsePortPowerClassifications IETF RFC 3621) B01010011, /* Type/Source/Priority Power type: Bits 7:6 11 = Type 1 PD 10 = Type 1 PSE 01 = Type 2 PD 00 = Type 2 PSE Power source: Bits 5:4 Where power type = PD 11 = PSE and local 10 = Local 01 = PSE 00 = Unknown Where power type = PSE 11 = Reserved 10 = Backup source 01 = Primary power source 00 = Unknown Reserved: Bits 3:2 Power Priority: Bits 1:0 11 = Low 10 = High 01 = Critical 00 = Unknown (default) */ 0x01, 0x90, // PD requested power value 1 to 510 decimal * 0.1 Watts (40W) 0x00, 0x00, // PSE allocated power value 1 to 510 decimal * 0.1 Watts 0x00, 0x00 // End of LLDP (type 0, length 0) // ADD CRC HERE? }; int buflen; // length of data to send void setup() { // initialize the w5100 chip and open a RAW socket W5100.init(); W5100.writeSnMR(s, SnMR::MACRAW); W5100.execCmdSn(s, Sock_OPEN); } void loop() { buflen=sizeof(buf); // we will be sending ‘buflen’ bytes across the wire // filling buffer with some data … // sending buffer…

suhwan · Answer

Dear narcosis219, My question is whether or not the W5100 appends FCS to the MACRAW packets automatically, or do I have to add it to the payload myself? W5100 appends FCS to the MACRAW packets automatically. Thanks,

narcosis219 · Answer

[quote=“suhwan”]Dear narcosis219, My question is whether or not the W5100 appends FCS to the MACRAW packets automatically, or do I have to add it to the payload myself? W5100 appends FCS to the MACRAW packets automatically. Thanks,[/quote] Hi suhwan, If the W5100 does append FCS automatically, then how do I fix my issue? If I send this packet to the switch, it reports CRC error. If I try to view the packet in Wireshark, on 1 laptop I can see the packet successfully, but on 2 other laptops I don’t see the packet at all. It looks like the CRC is not checking out. Is there anything I can do to fix this?

suhwan · Answer

Dear narcosis219, Anyway, your system (included W5100) has the CRC Error. If CRC of W5100 is uncorrect, you do not solve this problem. However, we have not reported the CRC Error. If the CRC of W5100 is correct, CRC error could be caused by hardware. Would you explain your hardware(schemetic) and network in more detail? Thanks,

narcosis219 · Answer

Hi suhwan, I am using the Arduino Ethernet board: arduino.cc/en/Main/ArduinoBoardEthernet Schematic and data can be found on there. The code I am using is in my first message. I am connecting the board directly into this switch: cisco.com/c/en/us/products/c … 09864.html It reports CRC errors. I am also connecting the board directly into the Ethernet port of Laptops. The Laptops are running Wireshark, but only 1 laptop can successfully receive the LLDP packets. The others do not see the packet. When I use UDP communication, there is no issue, but when I try to do LLDP with MACRAW, there are CRC errors.

suhwan · Answer

Hi narcosis219, Thank you for your explanation. It is used same algorithm for Ethernet CRC32 in UDP and MACRAW mode. If CRC algorithm in W5100 was uncorrect, it is happened same CRC errors in UDP mode. We don’t know whether or not the CRC32 is not support in LLDP. …but only 1 laptop can successfully receive the LLDP packets. Your code is verified. Please, check the setting of peer(switch or others laptop). ex.) When Laptop is connected PoE swtich, send LLDP packets by using LLDP packet generator. Thanks,

narcosis219 · Answer

[quote=“suhwan”]Hi narcosis219, Please, check the setting of peer(switch or others laptop). ex.) When Laptop is connected PoE swtich, send LLDP packets by using LLDP packet generator. [/quote] Hi suhwan, I have connected other computers and devices (Cisco IP Phone cisco.com/c/en/us/products/c … index.html) to the PoE Switch. All of them successfully communicate with LLDP. I have used LLDP packet generators and can successfully talk to the PoE Switch. Only the Arduino reports CRC errors.

narcosis219 · Answer

Hi suhwan, I noticed that on the Switch I forced 10BASE-T, then I no longer get CRC errors. Does this make sense?

suhwan · Answer

Hi narcosis219, I noticed that on the Switch I forced 10BASE-T, then I no longer get CRC errors. The algorithm of Ethernet CRC32 is same in 10BASE-T and 100BASE-T. We think that it is easy to effect noise in hardware when frequency is high (100BASE-T). Would you check whether or not CRC errors are happened when board (w/ PoE) is connected normal switch (not PoE switch)? Would you check whether or not CRC errors are happened when board (w/o PoE) is connected normal switch (not PoE switch)? Thanks,