<html><head></head><body>???<br>Two hosts directly connected with neither switch nor cross-over cable.<br>???<br><br>Sounds like the two nics auto-negotiated themselves to death.<br><br>To test, stop networking on boxA, rmmod nic modules, insmod nic modules, start networking. If ping runs a bit after that, disable autoconfig.<br><br><div class="gmail_quote">On April 19, 2021 1:06:07 PM EDT, Derek Atkins via Ale <ale@ale.org> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<pre class="k9mail">HI.<br><br>I'm having a strange networking issue between two AWOW devices running<br>Linux that stopped talking to each other. The devices are configured as<br>below:<br><br>--(a)[Box 1](b) ----- (c)[Box 2](d)--<br><br>Where:<br>(a) is 172.16.5.0/16<br>(b) is 172.16.5.1/16<br>(c) is 172.16.7.100/16<br>(d) is 172.16.7.0/16<br><br>The (b)/(c) link is a direct link between the devices, not a crossover<br>cable, and no switch.<br><br>The two devices were talking fine for a while and then all of a sudden<br>they stopped. Now that won't talk at all. When truing to ping .7.100<br>from Box 1, it sends out ARPs but there is no ARP response from Box 2. <br>Similarly, on Box 2 trying to ping .5.1 results in no ARP responses.<br><br>Both devices show the (b)/(c) link as up. Running ethtool shows the link<br>is detected. However arp -an shows an incomplete response (no surprise).<br><br>The dmesg output doesn't show anything.<br><br>I am at a loss. I don't understand how or why the two devices would stop<br>talking, and why neither will pick it up again.<br><br>Any suggestions for where to look or how else to debug this?<br><br>Thanks,<br><br>-derek<br></pre></blockquote></div><br>-- <br>Computers amplify human error<br>Super computers are really cool</body></html>