The ARP request is valid. It is a normal broadcast send to ff:ff:ff:ff:ff:ff:, and the source is the MAC address that I have set to the code. As it seems there is no problem there.
*Fotis Panagiotopoulos* *--* *AMCO S.A.* 25 Amfiaraou st. PO 10442, Athens, Greece Tel: +30 210 5907000 ext. -34 <%2B30%20210%205907000%20ext.%20-36> | Fax: +30 210 5912711 e-mail: [email protected] | web: http://www.amco.gr On Fri, Aug 12, 2016 at 7:56 PM, Chris Williams <[email protected]> wrote: > Quoting Fotis Panagiotopoulos <[email protected]>: > > Look at the wireshark ARP packet: > > It should send to the broadcast MAC address (ff:ff:ff:ff:ff:ff) > Look at your send MAC address. This should be valid. > > I have seen problems if your MAC address is 0. > > Chris. > > Well, it seems I narrowed down the problem. >> >> As I see in wireshark, when my microcontroller sends an ARP request about >> my gateway it does not receive any response. It continues sending the same >> request for about 30 secs (the time I wasn't seeing any UDP traffic), and >> then it starts sending the UDP packet. >> >> Two odd things are: >> the duration of the failed ARP requests is not constant, may be 10 to 50 >> secs. >> it never gets any response from the router on the ARP request. >> >> So practically I believe it is something about the ARP, that LWIP cannot >> find the address of the router, while it has no problems, resolving the >> address of the other local computers. Any hints? >> >> >> >> *Fotis Panagiotopoulos* >> >> >> *--* >> >> *AMCO S.A.* >> >> 25 Amfiaraou st. PO 10442, Athens, Greece >> Tel: +30 210 5907000 ext. -34 <%2B30%20210%205907000%20ext.%20-36> | >> Fax: +30 >> >> 210 5912711 >> e-mail: [email protected] | web: http://www.amco.gr >> >> On Fri, Aug 12, 2016 at 2:31 PM, Fotis Panagiotopoulos <[email protected]> >> wrote: >> >> OK I bought a managed switch, so I can now monitor the traffic on my >>> network correctly. I set up the port mirroring function, to forward all >>> traffic from the ethernet port the uC is connected, to the port that my >>> PC >>> is connected. I started wireshark but the problems persist. >>> >>> First my code starts LWIP, the MAC controller and sets a static IP with >>> no >>> problems. >>> >>> Then my code enters a loop and tries a DNS query. Here the fancy staff >>> starts. The first calls to dns_gethostbyname do not produce any traffic >>> (yes I properly wait for the callback function to check the result, >>> before >>> the next call). After continuing to call this function, I finally see >>> traffic in wireshark after app. 30 seconds. I can see an apparently >>> normal >>> DNS packet being sent but there is no response from the server. >>> >>> Then I tried to provide directly the IP of the server, (effectively I >>> stopped using the DNS functionality), and tried to directly connect to an >>> NTP server (using UDP of course). Again the same sumptoms. udp_send >>> returns >>> ERR_OK, but no traffic at the network. After app. 30 seconds I see the >>> packets being sent but again absolutelly no response from the server. >>> >>> Keep in mind that I can ping my device normally, that I tried many >>> servers >>> (which are proved to work, testing from my PC), that I double checked our >>> firewall (and that everything works OK from my PC). >>> >>> Also note that these problems exist only when I try to connect to an >>> external (to my LAN) server. Trying to connect to a local server works >>> normally. >>> >>> >>> >>> *Fotis Panagiotopoulos* >>> >>> >>> *--* >>> >>> *AMCO S.A.* >>> >>> 25 Amfiaraou st. PO 10442, Athens, Greece >>> Tel: +30 210 5907000 ext. -34 <%2B30%20210%205907000%20ext.%20-36> | >>> Fax: +30 >>> >>> 210 5912711 >>> e-mail: [email protected] | web: http://www.amco.gr >>> >>> On Mon, Aug 1, 2016 at 9:22 PM, [email protected] <[email protected]> >>> wrote: >>> >>> Fotis Panagiotopoulos wrote: >>>> >>>> I am asking for the brand/model number of the one that you are >>>>> successfully using, to search for a new or used one. As you can image >>>>> buying lots of switches in the hope that randomly one of them will have >>>>> this functionality, is not an good idea :) >>>>> >>>>> >>>> You don't have to buy randomly, just look for a switch that supports >>>> "port mirroring". These should be available from around ~100 EUR or >>>> USD... >>>> >>>> The more professional tool for monitoring would be an ethernet tap, >>>> which >>>> has two ports that work like a repeater and forwards both RX sides to a >>>> 3rd >>>> port (e.g. ETH or USB) to monitor via wireshark. >>>> >>>> If you want a cheaper solution, grab two network cards for your PC and >>>> build your own passive tap (e.g. like this: >>>> http://www.securityforrealpeople.com/2014/09/how-to-build-10 >>>> -network-tap.html). You'll have to monitor every side on its own (using >>>> wireshark), but you can mix 2 pcaps into one later if you prefer. >>>> Mixing is >>>> done via timestamps, so using 2 same cards (which are NOT USB) should >>>> give >>>> the best results. >>>> (ATTENTION: as this is passive and you attach a 2nd ETH receiver to one >>>> cable, using very short cables is recommended - and worked well for me >>>> once >>>> I tried!) >>>> >>>> Simon >>>> >>>> >>>> _______________________________________________ >>>> lwip-users mailing list >>>> [email protected] >>>> https://lists.nongnu.org/mailman/listinfo/lwip-users >>>> >>>> >>> >>> >> > > > -- > ------------------------------------------------------------ > --------------- > | Chris Williams EMail [email protected] > | > | Web www.chrydesn.co.uk > | > | Tel/Fax 01686 688065 | > | Chrysalis Design. Electronics, Computers, Hardware, Software. | > | Design and development to meet all your needs. | > ------------------------------------------------------------ > --------------- > > > > > > _______________________________________________ > lwip-users mailing list > [email protected] > https://lists.nongnu.org/mailman/listinfo/lwip-users >
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