[HECnet] DECnet for Linux

Some more notes on this: The problem of accessing a Linux machine seems to be related to the standard mtu of 1500 of a network interface. Reducing the maximum packet size to 576 helps; https://sourceforge.net/p/linux-decnet/mailman/message/2395733/ This can be done using ifconfig or using 576 instead of dst_mtu() in dn_current_mss() af_decnet.c of the kernel module source. tcpdump shows that a large data packet is one byte too long. Perhaps this occurs because the pad byte in the header is not counted in dn_mss_from_pmtu() in af_decnet.c; with an additional mtu-- this seems to be fixed. Kernel warnings related to dst.h; https://www.spinics.net/lists/netdev/msg225996.html indeed disappear by using dst_metric_raw at two places. The above was tested with kernel 3.10.17, and can be tested with http://mim.update.uu.se/hecnet and nodename RULLFL. dntype mim::nodenames.dat works very well on a real machine; why it doesn't work very well with the virtual machine is not really solved yet... On Wed, Jan 03, 2018 at 04:44:54PM +0100, Johnny Billquist wrote: > On 2018-01-03 16:02, Erik Olofsen wrote: > >On a virtual machine with lubuntu 12.04, kernel 3.2.0, I have > >DECnet for Linux V.2.5.68s working, with dnprogs version 2.65. > >It is node RULLFL. > > > >The daemons and utilities use decnet.conf with node information, > >so something useful would be to create it from mim::nodenames.dat. > > > >On a VAX, TYPEing it works well, but on the Linux machine, dntype > >hangs after giving parts of the file; dndir mim:: works well. > > > >Does anyone have dntype mim::nodenames.dat working properly (with > >perhaps different versions of the above)? > > I can't help, but I can report that trying to read a file from a Linux > machine on MIM also hangs after a while. > A big problem with the DECnet/Linux implementation is that the developers > only ever tested against VMS, and nothing else. > > I've known for ages that it does not play well with RSX. But I do not want > to dig into the Linux implementation. > > (The Linux DAP claims to be a VMS system, by the way, which is probably also > not a good idea. Better if it had claimed to be some Unix derivative.) > > Johnny > > -- > Johnny Billquist || "I'm on a bus > || on a psychedelic trip > email: bqt at softjar.se || Reading murder books > pdp is alive! || tryin' to stay hip" - B. Idol