Can not convert a LLDP packet to bytes

[UlyssesWu]

As description in HERE, when constructing a LLDP packet and getting bytes by calling Packet.Bytes, we will get a NullReferenceException (see the stackoverflow page for details).

And there is a workaround in that page:

var packet = LLDPPacket.RandomPacket();
var lldpBytes = packet.Bytes;
var lldpPacket = new LLDPPacket(new ByteArraySegment(lldpBytes));

After "reparsing" we can get the bytes. I think this may be a bug. also see

[chmorgan]

Hello. If you had a .pcap file with the least number of packets required to reproduce the issue I could use that to create a unit test and fix this issue.

[UlyssesWu]

You may add a test at LldpTest.cs like this:

    [Test]
    public void AsPayloadTest()
    {
        PhysicalAddress NDP_MULTICAST =
       new PhysicalAddress(new byte[] { 0x01, 0x23, 0x20, 0x00, 0x00, 0x01 });
        LLDPPacket lldpPacket = new LLDPPacket();
        lldpPacket.TlvCollection.Add(new ChassisID(NDP_MULTICAST));
        lldpPacket.TlvCollection.Add(new PortID(PortSubTypes.PortComponent, BitConverter.GetBytes(6633)));
        lldpPacket.TlvCollection.Add(new TimeToLive(120));
        lldpPacket.TlvCollection.Add(new EndOfLLDPDU());
        // reparse these bytes back into a lldp packet
        //lldpPacket = new LLDPPacket(new ByteArraySegment(lldpPacket.Bytes));

        EthernetPacket ethernet = new EthernetPacket(NDP_MULTICAST, NDP_MULTICAST, EthernetPacketType.LLDP);
        ethernet.PayloadPacket = lldpPacket;
        var bytes = ethernet.Bytes;
        Assert.NotNull(bytes);
    }

It throws NullReferenceException. After uncomment that "reparse" line, the test would succeed. I don't know if I shouldn't call methods in that way...

[chmorgan]

Hi @UlyssesWu. I'm closing this out as it has been open for a while now but we appreciate you reporting it. We would love to have a PR to help resolve this issue and add a test for this case, we just haven't had the time to resolve it here.