<div dir="ltr"><div class="gmail_quote"><div>Hi All,</div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>I think you're saying that it's not surprising that dnsmasq is not reading from the socket because the send queue is also full.</div></div></blockquote><div><br></div><div>As per this thread on netdev (<a href="https://lore.kernel.org/netdev/CABUuw65R3or9HeHsMT_isVx1f-7B6eCPPdr+bNR6f6wbKPnHOQ@mail.gmail.com/">https://lore.kernel.org/netdev/CABUuw65R3or9HeHsMT_isVx1f-7B6eCPPdr+bNR6f6wbKPnHOQ@mail.gmail.com/</a>) it seems we were consuming the socket send buffer with pending packets waiting for ARP responses that were never coming. This was causing failures sending to devices that were still live.</div><div><br></div><div>As per that thread we increased the <span style="color:rgb(0,0,51);font-size:13px;white-space:pre-wrap">/proc/sys/net/core/wmem_default value so all sockets will have larger send buffers (the device has very few sockets in use). It might be useful to add dnsmasq config options to increase </span><span style="color:rgb(0,0,51);font-size:13px;white-space:pre-wrap">SO_SNDBUF on the dhcp and dns sockets to allow more granular control.</span></div><div><span style="color:rgb(0,0,51);font-size:13px;white-space:pre-wrap"><br></span></div><div><span style="color:rgb(0,0,51);font-size:13px;white-space:pre-wrap">Thanks,
Tom Keddie</span></div></div></div>