Hi Julien. Yes, there is a TCP retransmission from your host. I bet that is because when the two packets come in such a close proximity your Ethernet driver is losing the second one. This, in fact, can be because there is a problem with the driver itself, or you have a really low-memory condition and the driver can't find enough memory to store the packet. If I would have to hunt this witch, I would start by setting a breakpoint on the Ethernet driver low_level_input() routine, somewhere around here:
static struct pbuf * low_level_input(struct netif *netif) { [...] /* We allocate a pbuf chain of pbufs from the pool. */ p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL); if (p != NULL) { [...] read data into(q->payload, q->len); } acknowledge that packet has been read(); [...] } else { drop packet(); <------------- It actually depends on how the one who actually wrote the driver wanted to make it difficult for you. Let me know how it goes. Cheers -- _______________________________________________ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users