6 May
2018
6 May
'18
1:32 p.m.
What Mark actually is talking about, and referring to, is the question
if sending packets are also seen by others connected to the same
interface and receiving packets.
It's a bit more complicated than just saying "BSD" does this, or
"Linux"
does that. But the bottom line is that some systems, and some hardware,
makes outgoing packets also visible to programs reading from the
interface, and other combinations do not.
And if you do not receive outgoing packets, then two virtual machines on
the same host, using the same interface, cannot communicate with each other.
Johnny
On 2018-05-06 04:00, Mark Pizzolato wrote:
Mark,
I?ve seen no evidence that anything has changed at all on Linux or other
operating systems. ??Changes have been made within simh to better
support some situations where bridges are used, but some sort of bridge
setup needs to be done like it did long ago.
Please point at specifics of what you are seeing that now allows telnet
to an emulator?s IP address without setting up some sort of bridging.
-Mark
*From:*owner-hecnet at Update.UU.SE [mailto:owner-hecnet at Update.UU.SE] *On
Behalf Of *Mark Abene
*Sent:* Saturday, May 5, 2018 3:57 PM
*To:* hecnet at update.uu.se
*Subject:* Re: [HECnet] Connections?
Nothing of the sort. I'm saying that in the past, you couldn't telnet to
an emulator's IP address from within the same host server. Naturally the
host server has multiple IPs for all the emulated guest OSes. This was a
well known and well documented peculiarity of BSD and Linux when logged
into a shell on the host server. It's no longer the case on more recent
Linux systems.
-Mark
On Sat, May 5, 2018, 10:56 AM Mark Pizzolato <Mark at infocomm.com
<mailto:Mark at infocomm.com>> wrote:
Hi Mark,
I?m not understanding what you saying here.
Are you suggesting that on a single host system, you?ve got multiple
independent simulators running which all are using the same IP
address as the host system? And, if true these devices can then, not
only uniquely communicate with remote systems (on the Internet say),
and also to each other AND the host system?
-Mark
*From:*owner-hecnet at Update.UU.SE <mailto:owner-hecnet at Update.UU.SE>
[mailto:owner-hecnet at Update.UU.SE
<mailto:owner-hecnet at Update.UU.SE>] *On Behalf Of *Mark Abene
*Sent:* Saturday, May 5, 2018 10:45 AM
*To:* hecnet at update.uu.se <mailto:hecnet at update.uu.se>
*Subject:* Re: [HECnet] Connections?
This is an often misunderstood generalization, with some people able
and others not. I remember this being true on *BSD. You could not
connect to a simulated IP on the same host. It *used* to also be
true on Linux, but is no longer the case for some time. On my ubuntu
server where I run dynamips, simh, and klh10, all on bridged taps, I
can telnet to all instances, even locally.
-Mark
On Sat, May 5, 2018, 12:27 AM Johnny Billquist <bqt at softjar.se
<mailto:bqt at softjar.se>> wrote:
On 2018-05-05 03:39, Robert Armstrong wrote:
--
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
>since once Multinet grabs the interface, I
can?t get to the
underlying
host.
? ? Actually I think it?s a limitation in simh and the pcap
library ? the
simh guest OS can?t talk to the host OS on the
same
interface.? You can
work around the problem with a TAP device.? Check
the
archives for the
simh mailing list ? it?s been discussed many
times before.
No. That is not correct. I run simh myself on a machine where I
have
both the native host and simh talking on the same ethernet. And
they are
both reachable by other hosts.
The OP must be doing something else funny.
? ?Johnny
--
Johnny Billquist? ? ? ? ? ? ? ? ? || "I'm on a bus
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?||? on a psychedelic trip
email: bqt at softjar.se <mailto:bqt at softjar.se>? ? ? ? ? ? ?||
Reading murder books
pdp is alive!? ? ? ? ? ? ? ? ? ? ?||? tryin' to stay hip" - B. Idol