Hi Marc, Unfortunately ?tap-info does not show any information like "announce" or "query".
I do see lot of messages like #log warn raw discarding frame of unknown type 0x808 and length 72 #log warn raw discarding frame of unknown type 0x808 and length 600 #log warn raw write to tap device tap3 failed: Invalid argument and so on... Best Regards, Amit On 01-Apr-16 10:14 AM, Marc Welz wrote: > On Thu, Mar 31, 2016 at 2:23 PM, Amit Bansod <[email protected]> > wrote: > >> In our setup, we have ROACH2 board sending data out via a 40G switch. >> Sometimes the data is broadcast from ROACH2 boards instead of sending to >> a particular ip address. > > Some more information on this: If the roach can't resolve and IP > address to a MAC address on the network, it defaults to broadcasting. > This is not ideal, but makes it possible to have extraordinarily dumb > receivers. However, it of course does consume bandwidth... > > Newer tcpborphservers have various tunable parameters to control the > rate at which the network is queried - see ?tap-arp-config, and > ?tap-info to display this - note the "announce" and "query" lines in > the latter. It might be useful to run tap-info after a tap-start to > count the number of detected stations/peers and only then start > transmission of the data streams, to limit the amount of broadcasting > (and thus not flood other roaches, which might still be resolving > their peers). > > ARP on the roaches is a bit unusual, as the gateware data streams > can't be paused/buffered while a peer is resolved - instead the full > subnet is pre-populated, and then continuously queried at a lower > rate. > > The source for all this is in > github.com/ska-sa/katcp_devel/tcpborphserver, let me know if you spot > something which doesn't look correct. > > regards > > marc >
