Hi Dale, The setting is required on the data receive computer side, and is done by our system administrator in GB.
Sorry but I do not know how to set that myself. Glen > Hi Glen, > > Thanks for the reply, and the useful example from your system. It looks > like a configuration problem on the ROACH side, then. Is there a > configuration file somewhere that tells tgtap about Jumbo packets and so > on? We are sending 6k packets, so will definitely need it. I do not see > any information on that from tgtap -h, and there is no man page. > > Regards, > Dale > ________________________________________ > From: Glen Langston [[email protected]] > Sent: Thursday, January 05, 2012 11:45 PM > To: Gary, Dale > Cc: [email protected] > Subject: Re: [casper] Problem with tap? > > Hi > > Your commands seem fine, (but not the mac address). > > One note, the 10 GBe is not configured for jumbo packets. > > For Jumbo packets you'd expect > > MTU:9000 > > ie for our 10 GBe link to a bee2 we have: > > eth2 Link encap:Ethernet HWaddr 00:60:DD:45:9F:76 > inet addr:192.168.3.68 Bcast:192.168.3.255 Mask:255.255.255.0 > UP BROADCAST RUNNING MULTICAST MTU:9000 Metric:1 > RX packets:1090598864 errors:0 dropped:0 overruns:0 frame:0 > TX packets:131516 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:1000 > RX bytes:8766147319262 (7.9 TiB) TX bytes:14799961 (14.1 MiB) > Interrupt:90 > > Glen > >> Hi All, >> >> I am setting up a ROACH at the observatory that worked fine in the lab. >> However, here I am not getting 10Gbe packets, although the internal >> counters show that the design is creating them. I looked around and >> believe I have a problem with the tap creation. The Python script does >> this: >> >> print 'Configuring transmitter core...', >> sys.stdout.flush() >> >> fpga.tap_start('tap3',tx_core_name,mac_base+source_ip,source_ip,fabric_port) >> print 'done' >> >> where >> >> source_ip=10*(2**24) + 20 #10.0.0.20 >> mac_base=(2<<40) + (2<<32) >> >> I therefore expect a hardware address 00 02 02 10 00 00 20. When I do >> an >> ifconfig, I see >> >> tap3 Link encap:UNSPEC HWaddr >> 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 >> inet addr:10.0.0.20 P-t-P:10.0.0.20 Mask:255.255.255.0 >> UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1 >> RX packets:0 errors:0 dropped:0 overruns:0 frame:0 >> TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 >> collisions:0 txqueuelen:500 >> RX bytes:0 (0.0 b) TX bytes:0 (0.0 b) >> >> That is a lot of zeros in the hardware address! Am I right that this >> anomalous hardware MAC address is the cause of the problem? I could >> have >> some setup wrong somewhere. Any ideas what could cause this? All other >> register settings seem to work okay. >> >> Thanks, >> Dale >> > > >
