On 20/08/2011 11:18, Ben Gray wrote: > Thanks everyone, > > Cheers for the tips on the mac address, I must admit I wasn't aware of the > locally assigned bit in the address. > > As for H/W checksum offloading, the main problem is the datasheet for the > chip is under NDA which I'm unwilling to sign, so I'm working off the Linux > driver. It seems under Linux if the TCP/UDP checksum fails it reverts to a > software calculation and as far as I can tell FreeBSD doesn't do this. Hence > it seems under Linux the driver reports incorrect csums but the kernel covers > up for it. > > And thanks for the tips on network test tools, I'll check 'em it. I was > hoping there was a nice FOSS test tool. I might be wrong but i thought scapy (http://www.secdev.org/projects/scapy/ and in ports) was meant to be pretty good for crafting custom packets. I think its lacking ipv6 though. there is also nemesis (http://nemesis.sourceforge.net and in ports) This is based purely on reading too many mailing lists though, I havent actually needed to use either.
Vince > > Thanks, > Ben > > On 20 Aug 2011, at 03:11, Ben Hutchings <bhutchi...@solarflare.com> wrote: > >> On Fri, 2011-08-19 at 11:04 +0100, Ben Gray wrote: >>> Hi, >>> >>> I'm not sure if this the right list to post to, but here goes ... >>> >>> I'm currently writing a driver for the SMSC LAN95xx range of USB to >>> Ethernet adapter chips >>> (http://www.smsc.com/index.php?tid=300&pid=135&tab=1). The basic RX/TX >>> works and now I'm trying to get the H/W checksum offload working, >>> however I've come across some problems with the H/W implementation, e.g. >>> it doesn't work with small (<64 byte) packets. >>> >>> So I was wondering if anyone knows of any test tools I can use to >>> fire all the different unusual sort of packets at the interface to see >>> how the H/W csum reacts, i.e. runt packets, packets with IP options, >>> IPv6 packets with extension headers, etc. >> There are various commercial tools and test suites, and I would expect >> that most vendors of network controllers and IP blocks have their own >> test suites that attempt to cover this. I know Solarflare has used >> tools from Oktet Labs (see <http://www.oktetlabs.ru/test_env.rhtml>) >> among others. >> >>> Another question I had was; is there a kernel function to generate >>> a random MAC address ? Or is there a FreeBSD (or FOSS equivalent) >>> Ethernet manufacturer ID I could use for randomly generated MAC addresses ? >> [...] >> >> You can use any (almost) any address with byte 0 bit 0 cleared (not >> multicast) and byte 0 bit 1 set (locally assigned). I don't know >> whether FreeBSD has a function for this, but Linux has one which just >> gets 6 random bytes and then changes the first byte to conform to this. >> >> There are a small number of old OUIs which should be avoided; see >> <http://thread.gmane.org/gmane.linux.network/195545>. >> >> Ben. >> >> -- >> Ben Hutchings, Staff Engineer, Solarflare >> Not speaking for my employer; that's the marketing department's job. >> They asked us to note that Solarflare product names are trademarked. >> > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org" _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
