[Simh] Connecting to Ethernet

Mark Pizzolato - Info Comm Mark at infocomm.com
Tue Sep 4 14:41:29 EDT 2012


Hi David,

I'm wondering why you are not using simh v3.9.

If I had been participating in this discussion from the beginning I'd have recommended you start from the latest released code since there were numerous networking changes included there.

The simh v3.9-0 release code is available at: http://simh.trailing-edge.com/sources/simhv39-0.zip


-          Mark


From: simh-bounces at trailing-edge.com [mailto:simh-bounces at trailing-edge.com] On Behalf Of Sergey Oboguev
Sent: Tuesday, September 04, 2012 10:57 AM
To: david.d.miller at att.net; simh at trailing-edge.com
Subject: Re: [Simh] Connecting to Ethernet

(typos fixed)

Hi David,

To begin with, on host side you have network mask for A-class IP address defined as for C-class address.
Which *may* be ok, but subnet/broadcast masks definitions mismatch on host side and VAX side.
You need to have them equal.
This also distorts routing table on the host side.

See http://en.wikipedia.org/wiki/IP_classes

Note "may" in "may be ok". Though A/B/C class scheme is supposed to be retired, I'd rather stick to standard masking as initial step, just because not all software, especially legacy software, may implement non-standard masking 100% correctly. (As a matter of fact I have a set-up that uses A-class private subnet, but it uses standard-size A class masks, i.e. 255.0.0.0 rather than 255.255.255.0.)

Fix this for a start and see what happens.

This said, it is suspicious that DELQA MAC address does not appear in list of MAC addresses seen by the bridge and that tap0 counters are all 0.

But begin by fixing masks, do some pinging, and if it still does not work repost new data.
Also see if SHOW DEVICE XQ /FULL indicates any errors.

- Sergey

________________________________
From: "david.d.miller at att.net" <david.d.miller at att.net>
To: simh at trailing-edge.com
Sent: Tue, September 4, 2012 10:10:52 AM
Subject: Re: [Simh] Connecting to Ethernet
Sergey

I printed the data you asked for and made no changes to VAX because they looked OK to me.  TCPIP SHOW ROUTE looped and produced no output.

I appreciate your examination of this problem.

Diagnostic data follows......


On Linux(Ubuntu) IP: 10.0.0.2 kermel 2.6.38-15-generic .....

david at Thinkpad:~/vax$ ifconfig
br0       Link encap:Ethernet  HWaddr 00:16:36:29:e6:7b
          inet addr:10.0.0.2  Bcast:10.0.0.255  Mask:255.255.255.0
          inet6 addr: fe80::216:36ff:fe29:e67b/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:11 errors:0 dropped:0 overruns:0 frame:0
          TX packets:46 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:811 (811.0 B)  TX bytes:16459 (16.4 KB)

eth0      Link encap:Ethernet  HWaddr 00:16:36:29:e6:7b
          inet6 addr: fe80::216:36ff:fe29:e67b/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:81237 errors:0 dropped:0 overruns:0 frame:0
          TX packets:73843 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:80090941 (80.0 MB)  TX bytes:11682488 (11.6 MB)
          Interrupt:16

tap0      Link encap:Ethernet  HWaddr 86:bc:f0:f2:2c:de
          UP BROADCAST 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)


david at Thinkpad:~/vax$ brctl show
bridge name    bridge id        STP enabled    interfaces
br0        8000.00163629e67b    no        eth0
                            tap0
david at Thinkpad:~/vax$ brctl show br0
bridge name    bridge id        STP enabled    interfaces
br0        8000.00163629e67b    no        eth0
                            tap0
david at Thinkpad:~/vax$ brctl showmacs br0
port no    mac addr        is local?    ageing timer
  1    00:0d:4b:4b:3d:ab    no           6.52
  1    00:16:36:29:e6:7b    yes           0.00
  1    00:21:6a:75:6d:04    no          63.15
  2    86:bc:f0:f2:2c:de    yes           0.00
  1    e0:46:9a:58:62:14    no          31.61
david at Thinkpad:~/vax$ route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
10.0.0.0        0.0.0.0         255.255.255.0   U     0      0        0 br0
0.0.0.0         10.0.0.1        0.0.0.0         UG    0      0        0 br0

In SIMH ......

sim> sho ver
VAX simulator V3.8-1 [64b data, 64b addresses, Ethernet support]
sim> show xq
XQ, address=20001920-2000192F, no vector, MAC=08:00:2B:AA:BB:CC, type=DELQA, poll=100, attached to tap0

In OpenVMS V7.3  on node MYVAX   4-SEP-2012

$ tcpip show interface /full
 Interface: LO0
   IP_Addr: 127.0.0.1         NETWRK: 255.0.0.0         BRDCST:
                                                           MTU:  4096
     Flags: UP LOOP NOARP MCAST SMPX
                                  RECEIVE        SEND
   Packets                              0           0
     Errors                             0           0
   Collisions:                          0

 Interface: QE0
   IP_Addr: 10.0.0.99         NETWRK: 255.0.0.0         BRDCST: 10.255.255.255
 Cluster
    C_Addr:                 C_NETWRK:                 C_BRDCST:
                       Ethernet_Addr: 08-00-2B-AA-BB-CC    MTU:  1500
     Flags: UP BRDCST RUN MCAST SMPX
                                  RECEIVE        SEND
   Packets                              0           5
     Errors                             0           0
   Collisions:                          0

$ tcpip show route /full
MYVAX::SYSTEM 09:53:18 TCPIP$UCP CPU=00:00:03.15 PF=4490 IO=341 MEM=931
MYVAX::SYSTEM 09:53:22 TCPIP$UCP CPU=00:00:03.15 PF=4502 IO=347 MEM=943
MYVAX::SYSTEM 09:53:29 TCPIP$UCP CPU=00:00:03.16 PF=4502 IO=353 MEM=943
 Interrupt

SHOW ROUTE just hangs .. well, I see it's doing I/Os, but no results.

$ mc tcpip$ping 10.0.0.2

Hangs as well.


--- On Mon, 9/3/12, Sergey Oboguev <oboguev at yahoo.com> wrote:

From: Sergey Oboguev <oboguev at yahoo.com>
Subject: Re: [Simh] Connecting to Ethernet
To: david.d.miller at att.net, simh at trailing-edge.com
Date: Monday, September 3, 2012, 5:34 PM
Did you remember to configure the interface in TCP/IP services for OpenVMS?

Assuming for the sake of example that your host uses IP address 192.168.21.3 for

(initially) eth0 and (subsequently after bridging) br0, and assuming you want to
assign

IP address 192.168.21.200 to VAX instance, you need to configure QE0 inside VMS
as follows:

    $ TCPIP SET INTERFACE QE0 /HOST=192.168.21.200
    $ TCPIP SET CONFIGURATION INTERFACE QE0 /HOST=192.168.21.200

Depending on exact value of network addresses being used and network topology it

may be necessary to additionally specify options /NETWORK_MASK=n.n.n.n and
/BROADCAST_MASK=m.m.m.m, although usually VMS TCP/IP picks correct defaults for
the masks.

If it still does not work, please post the output of

    $ TCPIP SHOW INTERFACE /FULL
    $ TCPIP SHOW ROUTE /FULL

and (in Linux)

    ifconfig br0
    ifcongig eth0
    ifconfig tap0
    brctl show
    brctl show br0
    brctl showmacs br0
    route -n

and (at SIMH command console prompt)

    show xq

Thanks,
Sergey

________________________________
From: "david.d.miller at att.net" <david.d.miller at att.net>
To: simh at trailing-edge.com
Sent: Mon, September 3, 2012 4:10:48 PM
Subject: Re: [Simh] Connecting to Ethernet


Sergey

That was a big help, but I'm not there yet.  I did the following

$ sudo ./ linux-tap.sh create br0 eth0 tap0 david
$ sudo vax    ; to start SIMH
simh>   ; the usual stuff
simh> set xq mac=bla bla
simh> att tap0  ;  hooray, this is the first time this succeeded.
simh> boot cpu

When logged into VMS, I could PING and TELNET to LOCALHOST (and 127.0.0.1).
But alas, not to my physical host.  And my physical host can't see the VAX
either.

But I did so many things to get to this point that something else might be
screwed up, so I need to reboot linux and start this drill again.

Thanks for a great start!

Any other suggestions?

--- On Mon, 9/3/12, Sergey Oboguev <oboguev at yahoo.com> wrote:


>From: Sergey Oboguev <oboguev at yahoo.com>
>Subject: Re: [Simh] Basic questions
>To: david.d.miller at att.net, simh at trailing-edge.com
>Date: Monday, September 3, 2012, 12:20 PM
>
>
>> In particular I get the following error:
>> david at Thinkpad:~$ sudo brctl addbr br0
>> david at Thinkpad:~$ sudo ifconfig tap0 up
>> tap0: ERROR while getting interface flags: No such device
>
>Perhaps because
>
>    /usr/sbin/tunctl -t $TAPDEV -u $USERID
>
>is missing.
>
>You may find the following script helpful:
>http://oboguev.net/misc/linux-tap.sh.txt
>
>Usage is at the bottom or invokable as
>
>    ./linux-tap.sh help
>


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