Absolutely Paul :-)
If I had any previous experience with that kind of coding I would at least gave a look. Seriously, it's not a one man job, right?
Anyway , it was a nice idea..
So if there's a spare decbrouter 90 around I'm willing to try that.
Hans
Verzonden vanaf mijn BlackBerry 10-smartphone.
Origineel bericht
Van: Paul_Koning at Dell.com
Verzonden: zaterdag 3 januari 2015 16:54
Aan: hecnet at Update.UU.SE
Beantwoorden: hecnet at Update.UU.SE
Onderwerp: Re: [HECnet] Hecnet Peering/Python
On Jan 3, 2015, at 3:02 AM, Hans Vlems <hvlems at zonnet.nl> wrote:
Paul,
the latest supported VMS versions for Python are 2.7.8 for Alpha and 2.7.9
for Itanium.
Which kind of kills the experiment, right? :(
Hans
Pretty much. It would be possible to port the code back to that version, but it would be a fair amount of work and not something I d be interested in. I prefer Python 3 for new projects for a number of reasons; some of those affect pydecnet significantly.
I suppose you could see what s involved in building Python 3.3 on VMS? :-)
paul
On Jan 3, 2015, at 3:02 AM, Hans Vlems <hvlems at zonnet.nl> wrote:
Paul,
the latest supported VMS versions for Python are 2.7.8 for Alpha and 2.7.9
for Itanium.
Which kind of kills the experiment, right? :(
Hans
Pretty much. It would be possible to port the code back to that version, but it would be a fair amount of work and not something I d be interested in. I prefer Python 3 for new projects for a number of reasons; some of those affect pydecnet significantly.
I suppose you could see what s involved in building Python 3.3 on VMS? :-)
paul
Paul,
the latest supported VMS versions for Python are 2.7.8 for Alpha and 2.7.9
for Itanium.
Which kind of kills the experiment, right? :(
Hans
-----Oorspronkelijk bericht-----
Van: owner-hecnet at Update.UU.SE [mailto:owner-hecnet at Update.UU.SE] Namens
Paul_Koning at Dell.com
Verzonden: vrijdag 2 januari 2015 20:23
Aan: hecnet at Update.UU.SE
Onderwerp: Re: [HECnet] Hecnet Peering
On Jan 2, 2015, at 2:08 PM, Hans Vlems <hvlems at zonnet.nl> wrote:
It would be nice to move the connection off a Linux box to a VMS system.
There is a libpcap version for VMS, it's used by simh.
The problem is Python. AFAIK that i s just v2.7 for VMS. I know my systems
run that kit, but I don't use it much so a newer version may be available.
Hans
The Python 3.3 what s new document says that VMS is no longer supported
due to lack of a maintainer . So it may be possible to build Python 3.2 on
VMS. The current DECnet/Python code wants 3.3, but earlier on I used 3.2
and there isn t much that needs 3.3. (In other words, it would not be all
that hard to change it back to allow 3.2.)
paul
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01/03/15
On 01/02/2015 09:17 PM, Johnny Billquist wrote:
One can tunnel most anything over GRE, even raw Ethernet
frames,
regardless of the higher-level protocols. Hence the 'G' for
"Generic".
Yes. But you need some ingress and egress that makes use of it. Or
else
we could just as well argue that UDP can tunnel anything.
...which it can. ;) On a Cisco, assigning a DECnet cost to an
interface (and a GRE endpoint is a pseudo-interface on a Cisco) forms
that ingress/egress.
(I know YOU know this; I'm saying it for the benefit of those
here who
are just learning about this)
Actually, I don't know the details, even though I pretty much know how
it *could* be done. I've pretty much never actually worked on a Cisco
box. :-)
However, DECnet costs cannot possibly be related, as we're now not
talking about DECnet protocols. (LAT and MOP are not using DECnet...)
You need to somehow tell the Cisco box to grab all ethernet packets
with
a certain protocol number, and pass those on over the tunnel, and have
the other end do the reverse.
Assigning a DECnet cost to a tunnel endpoint pseudo-interface
causes
it to pay attention to DECnet packets.
Which is not LAT and MOP. Which is what I've written multiple times now.
:-)
Right. I didn't say it was.
Seemed to me you implied it. Oh well. Me and english... :-)
Oh, nono...I'm sorry if it seemed that way.
DECnet packets are routed by the Cisco router. MOP and LAT are not
protocols running on top of DECnet, but are their own protocols directly
on ethernet. Which is also why they in essence are "local only", as they
cannot be routed.
...but they can be bridged, which you can ALSO do with a GRE tunnel.
The very same GRE tunnel as is handling DECnet, in fact.
Yes. And this is where it comes to me not knowing Ciscos. I know how you
do it in general if we talk networking. And this is just what my bridge
does, except it don't use GRE, but is more simple and stupid. :-)
I wouldn't say that; I think it's just that GRE is more standardized,
and typically ends in a router, which gives it more powerful
capabilities...but not by virtue of it being GRE.
But I assume there must be a way to tell a Cisco to bridge an arbitrary
ethernet protocol, using GRE as the tunneling protocol.
Yes there is. You can also bridge ALL packets on a network to a
different network, regardless of protocol.
I remember looking at the GRE interface under NetBSD many years ago when
I wanted to setup HECnet, but the documentation confused me in the
details, and I just wanted something really simple, so I wrote my own
bridge instead. It was a dirty hack on a dark night. It does (more or
less) do what I needed, but it's really just a quick hack.
Yes. Computer operating system-based implementations tend to be a bit
ridiculous. In a router it's more natural. I'm sure being written by
"router people" has a big positive influence on its implementation as
well, as opposed to being written by "operating system people".
-Dave
--
Dave McGuire, AK4HZ/3
New Kensington, PA
On 2015-01-03 02:54, Dave McGuire wrote:
On 01/02/2015 08:43 PM, Johnny Billquist wrote:
One can tunnel most anything over GRE, even raw Ethernet frames,
regardless of the higher-level protocols. Hence the 'G' for
"Generic".
Yes. But you need some ingress and egress that makes use of it. Or
else
we could just as well argue that UDP can tunnel anything.
...which it can. ;) On a Cisco, assigning a DECnet cost to an
interface (and a GRE endpoint is a pseudo-interface on a Cisco) forms
that ingress/egress.
(I know YOU know this; I'm saying it for the benefit of those
here who
are just learning about this)
Actually, I don't know the details, even though I pretty much know how
it *could* be done. I've pretty much never actually worked on a Cisco
box. :-)
However, DECnet costs cannot possibly be related, as we're now not
talking about DECnet protocols. (LAT and MOP are not using DECnet...)
You need to somehow tell the Cisco box to grab all ethernet packets with
a certain protocol number, and pass those on over the tunnel, and have
the other end do the reverse.
Assigning a DECnet cost to a tunnel endpoint pseudo-interface causes
it to pay attention to DECnet packets.
Which is not LAT and MOP. Which is what I've written multiple times now.
:-)
Right. I didn't say it was.
Seemed to me you implied it. Oh well. Me and english... :-)
DECnet packets are routed by the Cisco router. MOP and LAT are not
protocols running on top of DECnet, but are their own protocols directly
on ethernet. Which is also why they in essence are "local only", as they
cannot be routed.
...but they can be bridged, which you can ALSO do with a GRE tunnel.
The very same GRE tunnel as is handling DECnet, in fact.
Yes. And this is where it comes to me not knowing Ciscos. I know how you do it in general if we talk networking. And this is just what my bridge does, except it don't use GRE, but is more simple and stupid. :-)
But I assume there must be a way to tell a Cisco to bridge an arbitrary ethernet protocol, using GRE as the tunneling protocol.
I remember looking at the GRE interface under NetBSD many years ago when I wanted to setup HECnet, but the documentation confused me in the details, and I just wanted something really simple, so I wrote my own bridge instead. It was a dirty hack on a dark night. It does (more or less) do what I needed, but it's really just a quick hack.
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
On 2015-01-03 02:49, Paul_Koning at Dell.com wrote:
On Jan 2, 2015, at 8:41 PM, Johnny Billquist <bqt at softjar.se> wrote:
On 2015-01-03 02:13, Paul_Koning at Dell.com wrote:
On Jan 2, 2015, at 7:57 PM, Johnny Billquist <bqt at softjar.se> wrote:
On 2015-01-02 19:07, Paul_Koning at Dell.com wrote:
On Jan 2, 2015, at 12:34 PM, Johnny Billquist <bqt at softjar.se> wrote:
On 2015-01-02 18:28, Hans Vlems wrote:
Is there an advantage if you use a tunnel in stead of Johnny's bridge
program which I use?
It scales better and use less network bandwidth, if that is a concern.
Less network bandwidth because the GRE tunnel doesn t use Ethernet padding and regular Ethernet headers, while the JB bridge is a bridge so it does have both of those?
That seems like the only difference; from the DECnet routing layer point of view, both are LAN links and the protocol operation is the same for both.
No, you're not thinking about the larger picture, Paul. :-)
Like I responded myself. One "problem" is all the routers that are broadcasting. Both hello messages and routing updates. And they need to go to all bridges connected. While if you had a tunnel between two routers, you'll end up with just the chatter between those two routers. Any routers located on each end, or elsewhere, is of no concern for the link.
But you re comparing different cases. GRE is like a two-station Ethernet; your bridge is more general. The flooding case of a bridge makes a difference only if you have more than two stations.
Right. But we should not talk about GRE here, because that just confuse the issue. The thing is, the Ciscos are routers, with a tunnel between the two routers. So you only have these two routers talking to each other over the tunnel.
With the bridge, you do not get that isolation. You will instead have every router on each side (even if you just have two points to the bridge) talking across the bridge. So the number of packets over the bridge is essentially proportional to the number of routers connected to the ethernet segments.
And in the HECnet specific case, the bridge actually have around 10 active points, and atleast one router at each point
Ok. But if someone wanted the efficiency of a GRE tunnel without having a device capable of talking that protocol, one could set up another instance of a JB bridge, with just those two systems on it. Then it would be just as efficient.
If you also placed a router between the rest of the net and the bridge then yes, then they become equivalent.
I agree that if you compare a point to point topology tunnel with a 10-point bridge, the two necessarily look rather different.
Yeah... :-)
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
On 01/02/2015 08:43 PM, Johnny Billquist wrote:
One can tunnel most anything over GRE, even raw Ethernet frames,
regardless of the higher-level protocols. Hence the 'G' for
"Generic".
Yes. But you need some ingress and egress that makes use of it. Or
else
we could just as well argue that UDP can tunnel anything.
...which it can. ;) On a Cisco, assigning a DECnet cost to an
interface (and a GRE endpoint is a pseudo-interface on a Cisco) forms
that ingress/egress.
(I know YOU know this; I'm saying it for the benefit of those
here who
are just learning about this)
Actually, I don't know the details, even though I pretty much know how
it *could* be done. I've pretty much never actually worked on a Cisco
box. :-)
However, DECnet costs cannot possibly be related, as we're now not
talking about DECnet protocols. (LAT and MOP are not using DECnet...)
You need to somehow tell the Cisco box to grab all ethernet packets with
a certain protocol number, and pass those on over the tunnel, and have
the other end do the reverse.
Assigning a DECnet cost to a tunnel endpoint pseudo-interface causes
it to pay attention to DECnet packets.
Which is not LAT and MOP. Which is what I've written multiple times now.
:-)
Right. I didn't say it was.
DECnet packets are routed by the Cisco router. MOP and LAT are not
protocols running on top of DECnet, but are their own protocols directly
on ethernet. Which is also why they in essence are "local only", as they
cannot be routed.
...but they can be bridged, which you can ALSO do with a GRE tunnel.
The very same GRE tunnel as is handling DECnet, in fact.
-Dave
--
Dave McGuire, AK4HZ/3
New Kensington, PA
On Jan 2, 2015, at 8:41 PM, Johnny Billquist <bqt at softjar.se> wrote:
On 2015-01-03 02:13, Paul_Koning at Dell.com wrote:
On Jan 2, 2015, at 7:57 PM, Johnny Billquist <bqt at softjar.se> wrote:
On 2015-01-02 19:07, Paul_Koning at Dell.com wrote:
On Jan 2, 2015, at 12:34 PM, Johnny Billquist <bqt at softjar.se> wrote:
On 2015-01-02 18:28, Hans Vlems wrote:
Is there an advantage if you use a tunnel in stead of Johnny's bridge
program which I use?
It scales better and use less network bandwidth, if that is a concern.
Less network bandwidth because the GRE tunnel doesn t use Ethernet padding and regular Ethernet headers, while the JB bridge is a bridge so it does have both of those?
That seems like the only difference; from the DECnet routing layer point of view, both are LAN links and the protocol operation is the same for both.
No, you're not thinking about the larger picture, Paul. :-)
Like I responded myself. One "problem" is all the routers that are broadcasting. Both hello messages and routing updates. And they need to go to all bridges connected. While if you had a tunnel between two routers, you'll end up with just the chatter between those two routers. Any routers located on each end, or elsewhere, is of no concern for the link.
But you re comparing different cases. GRE is like a two-station Ethernet; your bridge is more general. The flooding case of a bridge makes a difference only if you have more than two stations.
Right. But we should not talk about GRE here, because that just confuse the issue. The thing is, the Ciscos are routers, with a tunnel between the two routers. So you only have these two routers talking to each other over the tunnel.
With the bridge, you do not get that isolation. You will instead have every router on each side (even if you just have two points to the bridge) talking across the bridge. So the number of packets over the bridge is essentially proportional to the number of routers connected to the ethernet segments.
And in the HECnet specific case, the bridge actually have around 10 active points, and atleast one router at each point
Ok. But if someone wanted the efficiency of a GRE tunnel without having a device capable of talking that protocol, one could set up another instance of a JB bridge, with just those two systems on it. Then it would be just as efficient.
I agree that if you compare a point to point topology tunnel with a 10-point bridge, the two necessarily look rather different.
paul
On 2015-01-03 02:36, Dave McGuire wrote:
On 01/02/2015 08:12 PM, Johnny Billquist wrote:
One can tunnel most anything over GRE, even raw Ethernet frames,
regardless of the higher-level protocols. Hence the 'G' for "Generic".
Yes. But you need some ingress and egress that makes use of it. Or else
we could just as well argue that UDP can tunnel anything.
...which it can. ;) On a Cisco, assigning a DECnet cost to an
interface (and a GRE endpoint is a pseudo-interface on a Cisco) forms
that ingress/egress.
(I know YOU know this; I'm saying it for the benefit of those here who
are just learning about this)
Actually, I don't know the details, even though I pretty much know how
it *could* be done. I've pretty much never actually worked on a Cisco
box. :-)
However, DECnet costs cannot possibly be related, as we're now not
talking about DECnet protocols. (LAT and MOP are not using DECnet...)
You need to somehow tell the Cisco box to grab all ethernet packets with
a certain protocol number, and pass those on over the tunnel, and have
the other end do the reverse.
Assigning a DECnet cost to a tunnel endpoint pseudo-interface causes
it to pay attention to DECnet packets.
Which is not LAT and MOP. Which is what I've written multiple times now. :-)
DECnet packets are routed by the Cisco router. MOP and LAT are not protocols running on top of DECnet, but are their own protocols directly on ethernet. Which is also why they in essence are "local only", as they cannot be routed.
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
On 2015-01-03 02:13, Paul_Koning at Dell.com wrote:
On Jan 2, 2015, at 7:57 PM, Johnny Billquist <bqt at softjar.se> wrote:
On 2015-01-02 19:07, Paul_Koning at Dell.com wrote:
On Jan 2, 2015, at 12:34 PM, Johnny Billquist <bqt at softjar.se> wrote:
On 2015-01-02 18:28, Hans Vlems wrote:
Is there an advantage if you use a tunnel in stead of Johnny's bridge
program which I use?
It scales better and use less network bandwidth, if that is a concern.
Less network bandwidth because the GRE tunnel doesn t use Ethernet padding and regular Ethernet headers, while the JB bridge is a bridge so it does have both of those?
That seems like the only difference; from the DECnet routing layer point of view, both are LAN links and the protocol operation is the same for both.
No, you're not thinking about the larger picture, Paul. :-)
Like I responded myself. One "problem" is all the routers that are broadcasting. Both hello messages and routing updates. And they need to go to all bridges connected. While if you had a tunnel between two routers, you'll end up with just the chatter between those two routers. Any routers located on each end, or elsewhere, is of no concern for the link.
But you re comparing different cases. GRE is like a two-station Ethernet; your bridge is more general. The flooding case of a bridge makes a difference only if you have more than two stations.
Right. But we should not talk about GRE here, because that just confuse the issue. The thing is, the Ciscos are routers, with a tunnel between the two routers. So you only have these two routers talking to each other over the tunnel.
With the bridge, you do not get that isolation. You will instead have every router on each side (even if you just have two points to the bridge) talking across the bridge. So the number of packets over the bridge is essentially proportional to the number of routers connected to the ethernet segments.
And in the HECnet specific case, the bridge actually have around 10 active points, and atleast one router at each point...
It seems to me that both cases produce the same number of packets if you configure a connection between just two stations, because each multicast goes to the one other station either in the GRE case or the bridge case.
But you get so many more multicast packets if you listen to an ethernet segment with multiple routers...
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
