[Simh] VAX and networking on Linux/PPC

[Johnny Billquist]

Hi. I don't know what your problems are, but there are couple of things 
in your text that I can at least comment on...

On 2013-02-26 17:59, Lennert Van Alboom wrote:
> Hello there,
>
>
> Back with more problems with simh vax on linux/ppc. The earlier RAUSER problem
> was fixed (thanks Mark!) so I went on to install VMS in the VM. Until I got to
> networking...
>
> I cannot get TCP/IP to work on it. The line isn't completely dead though - I
> see some DECnet related traffic (endnode-hello) and there's outgoing packets as
> well, but overall communications fail (I can't ping, telnet or whatever from
> nor to the vax).
>
> I tried the following simh networking setups:
> - bridged setup with raw tapX device
> - bridged setup with built-in tap:tapX (as documented in 0readme_ethernet.txt)
> - bridged setup with "taptap" linked dual-tapX like in the 3.8 days
> - direct connection of eth0 (without host networking at all)
>
> Nothing works. I captured a tcpdump from a full boot sequence of this last setup:
>
> 	tcpdump: WARNING: eth0: no IPv4 address assigned
> 	tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
> 	listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
> 	17:38:31.041712
> 	17:38:31.234374
>
> ^^ DECnet MOP stuff (looks 'empty' unless I specify -vv, which spews a ton of garbage)
>
> 	17:38:32.287022 endnode-hello endnode vers 2 eco 0 ueco 0 src 1.42 blksize 1498 rtr 0.0 hello 15 data 2
> 	17:38:48.092170 endnode-hello endnode vers 2 eco 0 ueco 0 src 1.42 blksize 1498 rtr 0.0 hello 15 data 2
>
> ^^ More DECnet stuff

Standard decnet messages just telling that the machine exists.

> 	17:38:59.086423 ARP, Request who-has 192.168.1.124 tell 192.168.1.124, length 46
>
> ^^ VMS broadcasts the network to find its own MAC address? Heh.

Nope. It's called a gratuitous arp. It's something most systems do at 
startup to help detect if you have things misconfigured and have several 
machines configured with the same IP address. It is also good, as it 
flushes any arp caches on other machines that might be incorrect in case 
your machine now have a new mac address, and caches on other machines 
might not know.

> 	17:39:02.327686 endnode-hello endnode vers 2 eco 0 ueco 0 src 1.42 blksize 1498 rtr 0.0 hello 15 data 2
> 	17:39:17.391732 endnode-hello endnode vers 2 eco 0 ueco 0 src 1.42 blksize 1498 rtr 0.0 hello 15 data 2
> 	17:39:33.593397 endnode-hello endnode vers 2 eco 0 ueco 0 src 1.42 blksize 1498 rtr 0.0 hello 15 data 2
> 	17:39:37.598483 ARP, Request who-has 192.168.1.1 tell 192.168.1.124, length 46
> 	17:39:37.598610 ARP, Reply 192.168.1.1 is-at 00:8e:f2:4b:f1:f0 (oui Unknown), length 50
> 	17:39:38.759549 ARP, Request who-has 192.168.1.1 tell 192.168.1.124, length 46
> 	17:39:38.759655 ARP, Reply 192.168.1.1 is-at 00:8e:f2:4b:f1:f0 (oui Unknown), length 50
> 	17:39:40.773536 ARP, Request who-has 192.168.1.1 tell 192.168.1.124, length 46
> 	17:39:40.773649 ARP, Reply 192.168.1.1 is-at 00:8e:f2:4b:f1:f0 (oui Unknown), length 50
>
> ^^ This is where I tried to ping 192.168.1.1 (my router) from 192.168.1.124
> (the vax VMS). The ARP request gets on the network, and the reply enters the
> eth0 device. VMS doesn't see it though, and reports "100% packet loss".

So you are not receiving packets correctly. You need to figure that one 
out...

Do DECnet work, or is that also non-functional?

	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