On 6/6/2012 5:26 AM, Peter Coghlan wrote:
No, you have not misunderstood. You are just not getting the full
picture. Yes, the Cisco box will transport the DECnet frames inside
something. At the bottom there will be IP, but most likely the DECnet
frames are actually sitting inside UDP...
My understanding of it is that GRE is another IP protocol on the same level
as TCP and UDP rather than using UDP.
You are correct. GRE is Layer 4 just like TCP and UDP.
-brian
On 6/4/2012 8:51 PM, Dave McGuire wrote:
On 06/04/2012 12:13 PM, Brian Hechinger wrote:
SIMH 3.9 somehow kernel paniced my solaris server!
Wow.
-brian
ps: it's older solaris, but stil!
Holy cow! I have NEVER seen that happen. (which is why I run it!)
How the heck did you do that?
Built and ran SIMH 3.9
3.8-1 works just fine (it's what i'm running now) and 3.9 runs fine in my sol11 VM.
-brian
On 6/6/2012 9:04 AM, Peter Lothberg wrote:
Could this work in a domestic environment with an ISP that
gives out dynamic IP addresses?
My head hurts.. Ask for a /56 of IPv6 space. -:)
If there are many users that need this, I will look in to it, I thnk
there was magic that could be applied.
On the side with the dhcp address it's simple. You just make the source the actual interface and not an IP.
interface Tunnel0
description Tunnel for DECnet to Dave M.
no ip address
decnet cost 10
tunnel source FastEthernet0/1
tunnel destination 50.73.179.1
tunnel path-mtu-discovery
end
interface FastEthernet0/1
description Internet Connection (Cable Modem)
ip address dhcp
ip nat outside
ip virtual-reassembly
duplex auto
speed auto
end
Now, in my case it's actually a static IP but RCN require me to actually fetch my IP via DHCP or it won't work.
As to how to handle this on the other end, I have no clue. :)
-brian
On 6/6/2012 8:48 AM, Peter Lothberg wrote:
On 2012-06-05 03:50, Peter Lothberg wrote:
For people who don't need LAT and have a Cisco box, this is way better
than the bridge program.
(If you really want LAT with other parts of HECnet, then there is no
alternative to the bridge...)
You can bridge LAT with the cisco box... -:) ((It might even HELP you
with LAT over WAN....)) (And it can act as a LAT termianl server)
Nice. I did not know that. That's even better. Will it just bridge the
protocols you ask for, or will it do them all? Hmm, I assume it's using
GRE for this?
Johnny
I -think- there where special stuff to help with LAT in WAN scenarios,
at some point there might even have been a telnet/lat gw.. I have to
go and refresh my memory..
SuperLAT! It no longer says that in the version banner though.
bart#lat ?
WORD Name of a remote system
bart(config-subif)#lat ?
enabled Enable LAT protocol translation
host Statically define LAT services
-brian
No, you have not misunderstood. You are just not getting the full picture.
Yes, the Cisco box will transport the DECnet frames inside something. At
the
bottom there will be IP, but most likely the DECnet frames are actually
sitting
inside UDP...
So what is the difference from the bridge program, you ask.
Well, simple, the bridge program tries to be clever about which frames to
send where, but it cannot be clever enough at times, and also there are
times when it is forced to send traffic that we might want to limit.
The reason is that the bridge is not really a part of the DECnet traffic,
but is
just relaying packets back and forth, making the two ends of the bridge
appear as if they were on the same ethernet segment.
The Cisco box, on the other hand, is a DECnet routing node. It sits on the
ethernet, and participate fully in the DECnet traffic.
Thanks. Now I get it. I didn't know that anyone other than DEC ever made
something that could route actual DECnet and therefore did not realise that
"actual DECnet router" meant "actual DECnet router" :-) Until now I thought
this was something only available in a VMS router node.
It would be a fun exercise to turn the bridge into an actual DECnet router.
One day, when I have a lot of time I might even think about trying that.
Regards
Rob
As a good friend has commented to me, unless you plan on throwing a lot of money at Larry's yacht, you can forget any supposed "care" that Oracle may have. What you see is what you get... fortunately with Solaris, there may be a few souls left from the old organization that will go beyond google and a best endeavor.
Apologies... been fed up with Oracle now for quite some time...
On Mon, Jun 4, 2012 at 6:27 PM, Johnny Billquist <bqt at softjar.se> wrote:
On 2012-06-04 18:13, Brian Hechinger wrote:
SIMH 3.9 somehow kernel paniced my solaris server!
Wow.
-brian
ps: it's older solaris, but stil!
Wow. Now I am impressed. You have managed to trigger a bug in Solaris... :-)
Send an SPR to Oracle... If they care...
Johnny
On 2012-06-06 11:26, Peter Coghlan wrote:
No, you have not misunderstood. You are just not getting the full
picture. Yes, the Cisco box will transport the DECnet frames inside
something. At the bottom there will be IP, but most likely the DECnet
frames are actually sitting inside UDP...
My understanding of it is that GRE is another IP protocol on the same level
as TCP and UDP rather than using UDP.
You could definitely be right on GRE. It was way too long since I actually tried working with GRE to really remember much anymore...
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
No, you have not misunderstood. You are just not getting the full
picture. Yes, the Cisco box will transport the DECnet frames inside
something. At the bottom there will be IP, but most likely the DECnet
frames are actually sitting inside UDP...
My understanding of it is that GRE is another IP protocol on the same level
as TCP and UDP rather than using UDP.
Regards,
Peter Coghlan.
The Cisco box can have several point-to-point connections. Each is
considered its own interface (well, circuit I'd guess, but possibly also
line) in DECnet on the Cisco box.
In DECnet on PTP links in the DECnet architecture, like DDCMP links,
the DECnet routing protocol is spoken using incrmental updates, this
is what I beleive hapens with Multinet on VMS.
When a DECnet node speaks routing on a ETHERNET segment, it basically
dumps a "routing vector" every 3 seconds, depending on if you are area
router or just routing-4 you send all areas or just you own.
A routing vector has the area id, and then indexed with node-numbers
are 16-bit cost+hops, where 0 represent not reachable....... So
2 bytes*1024 nodes.
The cisco implemenation uses the LAN format with some optimizing
kludge.
-P
Forgive my ignorance, but when you say "actual DECnet routing", it must be
transporting it over something, what is that something? I assume it
is IP, in which case it would still need to encapsulate the DECnet
in IP wouldn't it? Have I misunderstood something here?
A bridge connects two ethernet segments together at the Ethernet
layer, they might have a learning mechanism so they knew what MAC
address is on what port, so if you have a multipoint network, all
packets are not sent everywhere.
Johnnys bridge takes a Etherent frame, puts it in a IP packet, sends
it to the other side, removes the outer iP header and sends the
Ethernet fram out on the physical ethernet on the other side.
A DECnet router is a L3 device, it will look at the packets and figure
out where it needs to go based on the DECnet address, not the MAC
address. It also speaks a routing protocol to figure out what is on
the other side, the same way IP has routing protocols. The closest IP
routing we have to DECnet is ISIS. OSPF is based on the same
principle, but (long rant..) it's backwards in many ways.
A L3 router can have many interfaces, and the interface type can be
anything, point-to-point, HDLC, DDCMP, POS (did anyone figure POS is
kludge DDCMP clone?) and the L2 header is stripped off.
Now, in DECnet on a LAN segment there is a kludge, there is no ND or
ARP, instead the DECnet node address is "hard coded" in to the MAC
address.. aa00.0400.xxxx
To get xxxx multiplie the area number by 1,024 and add the node
number to the product. The resulting 16-bit decimal address is
converted to a hexadecimal number and appended to the address
AA00.0400 in byte-swapped order, with the least significant byte
first. For example, DECnet address 12.75 becomes 12363 (base 10),
which equals 304B (base 16).
Now, so think of a L3 router with a physical Ethernet on one side and
a logical (GRE or other tunnel interface) on the other side. The
traffic across the IP network in this case will be the GRE encapsulate
Ethernet frame with address as above and ethertype 0x6003.
This is DECnet Phase 4, on DEcnet Phase 5 it's all OSI-IP/CLNP and I
have forgotten all of it as OSI died..
And dept of useless knowledge, Tops10 ANF10 uses 0x6016
--Peter
