On Sat, 28 Feb 2015, Johnny Billquist wrote:
How are you doing more than one line without bridges or repeaters? Have
I misread?
(Not counting routing)
I was referring to repeaters. They are totally invisible to the ethernet, so I do not consider to cables connected by a repeater to be two different ethernet segments.
Ahhhh.
But if others do consider that separate segments, then we atleast understand each other. :-)
Yeah. I understand you now.
But the reality of it is that on your ethernet connection, you can see more than 199 other machines, even without switches or bridges.
The 500m limit of the ethernet cable is just because of signal quality. The design as such put an upper limit on how far apart two hosts can be, in time, for the collision detection to work properly. The is a hard limit.
The 2.5 meter between transcievers is also more of an effect of physics. :-)
Physics always get in the way!
Hmmmm, when did VMS/BSD get software bridging capabilities?
No idea. Can VMS do bridging now?
Not sure, that's why I was asking. ;)
Johnny
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects
Afternoon all,
Anyone have schematics for the 4000/60 PSU? Mine's acting funny again. THinking I should probably just recap it.
Harddrive kept spinning down, then back up...then right back down. Powered the entire thing off, attempted to turn back on to no avail. Let sit for several minutes and it powered right back up. Drive seems to remain spinning now.
Any other specific components I should test and replace while in there for the recap?
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects
Bridges and repeaters, DEB ETs and DEREPs, are proprietary dedicated devices.
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Onderwerp: Re: [HECnet] Maximum number of L2 routers?
On Sat, 28 Feb 2015, Johnny Billquist wrote:
Not sure what you mean with a star configuration. The first (proprietary)
glass fiber repeaters were star designs, was that what you meant?
Not all ethernet segments have to be in one line. But since the maximum
number of repeaters between any two nodes were two, you could (obviously)
have repeaters in configurations that just made sure not more than two were
involved in any given path, but there could be more than two totally.
The simplest such configuration would be a star.
How are you doing more than one line without bridges or repeaters? Have I
misread?
(Not counting routing)
But my memory is fuzzy enough at this point that I should probably go read
the docs instead of continuing to ramble here...
DEC also sold remote bridges and repeaters. A glass fiber trunc connected
either two remote repeaters or bridges or one of each. I forgot how long a
fiber segment could be, 2500 m IIRC. That gave you some room to plan on a
large site. Two remote repeaters counted as one in the two repeater rule.
Expensive stuff though. A Lanbridge 100 was 30.000 guilders in 1988. A
remote bridge was even more expensive.
Yeah.
But the ethernet was older than those devices. If my memory serves me right,
the original repeater (from DEC) was the DEREP. Probably even more expensive
back in the day. :-) And there were no bridges back then.
Hmmmm, when did VMS/BSD get software bridging capabilities?
Johnny
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects
Correct, the 200 node limit was for one cablesegment
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Onderwerp: Re: [HECnet] Maximum number of L2 routers?
On 2015-02-28 22:01, Hans Vlems wrote:
That's right, two repeaters between any two stations which gave you 1680 meters spanned distance. The extra 180 meters come from four transceiver cables, 45 m each.
So, the 200 node limit can't really be right, unless you really are only
talking about one cable, and not an ethernet, as a repeater is totally
invisible to you, and makes it possible to connect more machines on the
ethernet.
The repeater rule btw is lifted by a bridge. And there is a maximum of 7 bridges between stations.
Well, proper bridges are definitely a different thing than a repeater,
as a bridge will store and forward.
Not sure what you mean with a star configuration. The first (proprietary) glass fiber repeaters were star designs, was that what you meant?
Not all ethernet segments have to be in one line. But since the maximum
number of repeaters between any two nodes were two, you could
(obviously) have repeaters in configurations that just made sure not
more than two were involved in any given path, but there could be more
than two totally.
The simplest such configuration would be a star.
But my memory is fuzzy enough at this point that I should probably go
read the docs instead of continuing to ramble here...
DEC also sold remote bridges and repeaters. A glass fiber trunc connected either two remote repeaters or bridges or one of each. I forgot how long a fiber segment could be, 2500 m IIRC . That gave you some room to plan on a large site. Two remote repeaters counted as one in the two repeater rule.
Expensive stuff though. A Lanbridge 100 was 30.000 guilders in 1988. A remote bridge was even more expensive.
Yeah.
But the ethernet was older than those devices. If my memory serves me
right, the original repeater (from DEC) was the DEREP. Probably even
more expensive back in the day. :-) And there were no bridges back then.
Johnny
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Onderwerp: Re: [HECnet] Maximum number of L2 routers?
On 2015-02-28 21:21, Hans Vlems wrote:
Yeah of course you can have more than one L2 router in an area, didn't think of it :)
:-)
About the 10base5 segment, that was limited in length to 500 meters. Transceivers must be at least 2.5 meters apart, hence the 200 nodes. This was before a DELNI was invented. If my failing memory doesn't fail me that 200 node limit remained the same with Delni's.
But you were allowed to bridge several segments (using repeaters). I
think the maximum distance, including hops, between any two nodes had to
be within 1000m, but you could also do stars... You were not allowed to
have more than two repeaters I also seem to remember.
Johnny
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Onderwerp: Re: [HECnet] Maximum number of L2 routers?
On 2015-02-28 20:51, Hans Vlems wrote:
64:-)?
You can definitely have more than one L2 router per area... :-)
I don't know for sure, as you probably have guessed...
There is an ncp executor parameter called maximum broadcast routers, default value 32 iirc.
Is there an architectural limit, depends on what you mean by ethernet segment. A 10base5 segment was limited to 200 nodes. 64 L2 routers might put a hefty broadcast load on it. On an extended ethernet LAN there is likely no technical limit.
Really? I have some vague memory of some limit of an ethernet segment,
but I can't recall any details now. Why 200?
Johnny
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Onderwerp: [HECnet] Maximum number of L2 routers?
Hello, list,
I'm trying to remember what is the maximum number of area routers allowed in a DECNET Phase IV ethernet segment. Anyone of you have that information at hand?
On other news, the old macbook I was using as home server has died, after years of service beyond the call of duty. I'm setting up my stuff using several smallish ARM computers. To be specific, now I'm running a cubietruck and and Odroid-C1 (and a raspberry Pi as router/firewall). I'm having trouble with the net connectivity, so some yo-yo disconnects from area 7 should be expected. Not so hard as last sunday, but I'm still doing quite a lot of reboots.
BTW, the SG1 multinet link seems to be down again (unless it is a problem in my side, which is completely possible).
--
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 2015-02-28 22:24, Cory Smelosky wrote:
On Sat, 28 Feb 2015, Johnny Billquist wrote:
Not sure what you mean with a star configuration. The first
(proprietary) glass fiber repeaters were star designs, was that what
you meant?
Not all ethernet segments have to be in one line. But since the
maximum number of repeaters between any two nodes were two, you could
(obviously) have repeaters in configurations that just made sure not
more than two were involved in any given path, but there could be more
than two totally.
The simplest such configuration would be a star.
How are you doing more than one line without bridges or repeaters? Have
I misread?
(Not counting routing)
I was referring to repeaters. They are totally invisible to the ethernet, so I do not consider to cables connected by a repeater to be two different ethernet segments.
But if others do consider that separate segments, then we atleast understand each other. :-)
But the reality of it is that on your ethernet connection, you can see more than 199 other machines, even without switches or bridges.
The 500m limit of the ethernet cable is just because of signal quality. The design as such put an upper limit on how far apart two hosts can be, in time, for the collision detection to work properly. The is a hard limit.
The 2.5 meter between transcievers is also more of an effect of physics. :-)
But my memory is fuzzy enough at this point that I should probably go
read the docs instead of continuing to ramble here...
DEC also sold remote bridges and repeaters. A glass fiber trunc
connected either two remote repeaters or bridges or one of each. I
forgot how long a fiber segment could be, 2500 m IIRC. That gave you
some room to plan on a large site. Two remote repeaters counted as
one in the two repeater rule.
Expensive stuff though. A Lanbridge 100 was 30.000 guilders in 1988.
A remote bridge was even more expensive.
Yeah.
But the ethernet was older than those devices. If my memory serves me
right, the original repeater (from DEC) was the DEREP. Probably even
more expensive back in the day. :-) And there were no bridges back then.
Hmmmm, when did VMS/BSD get software bridging capabilities?
No idea. Can VMS do bridging now?
Johnny
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 Sat, 28 Feb 2015, Johnny Billquist wrote:
Not sure what you mean with a star configuration. The first (proprietary) glass fiber repeaters were star designs, was that what you meant?
Not all ethernet segments have to be in one line. But since the maximum number of repeaters between any two nodes were two, you could (obviously) have repeaters in configurations that just made sure not more than two were involved in any given path, but there could be more than two totally.
The simplest such configuration would be a star.
How are you doing more than one line without bridges or repeaters? Have I misread?
(Not counting routing)
But my memory is fuzzy enough at this point that I should probably go read the docs instead of continuing to ramble here...
DEC also sold remote bridges and repeaters. A glass fiber trunc connected either two remote repeaters or bridges or one of each. I forgot how long a fiber segment could be, 2500 m IIRC. That gave you some room to plan on a large site. Two remote repeaters counted as one in the two repeater rule.
Expensive stuff though. A Lanbridge 100 was 30.000 guilders in 1988. A remote bridge was even more expensive.
Yeah.
But the ethernet was older than those devices. If my memory serves me right, the original repeater (from DEC) was the DEREP. Probably even more expensive back in the day. :-) And there were no bridges back then.
Hmmmm, when did VMS/BSD get software bridging capabilities?
Johnny
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects
On 2015-02-28 22:01, Hans Vlems wrote:
That's right, two repeaters between any two stations which gave you 1680 meters spanned distance. The extra 180 meters come from four transceiver cables, 45 m each.
So, the 200 node limit can't really be right, unless you really are only talking about one cable, and not an ethernet, as a repeater is totally invisible to you, and makes it possible to connect more machines on the ethernet.
The repeater rule btw is lifted by a bridge. And there is a maximum of 7 bridges between stations.
Well, proper bridges are definitely a different thing than a repeater, as a bridge will store and forward.
Not sure what you mean with a star configuration. The first (proprietary) glass fiber repeaters were star designs, was that what you meant?
Not all ethernet segments have to be in one line. But since the maximum number of repeaters between any two nodes were two, you could (obviously) have repeaters in configurations that just made sure not more than two were involved in any given path, but there could be more than two totally.
The simplest such configuration would be a star.
But my memory is fuzzy enough at this point that I should probably go read the docs instead of continuing to ramble here...
DEC also sold remote bridges and repeaters. A glass fiber trunc connected either two remote repeaters or bridges or one of each. I forgot how long a fiber segment could be, 2500 m IIRC . That gave you some room to plan on a large site. Two remote repeaters counted as one in the two repeater rule.
Expensive stuff though. A Lanbridge 100 was 30.000 guilders in 1988. A remote bridge was even more expensive.
Yeah.
But the ethernet was older than those devices. If my memory serves me right, the original repeater (from DEC) was the DEREP. Probably even more expensive back in the day. :-) And there were no bridges back then.
Johnny
Verzonden vanaf mijn BlackBerry 10-smartphone.
Origineel bericht
Van: Johnny Billquist
Verzonden: zaterdag 28 februari 2015 21:28
Aan: hecnet at Update.UU.SE
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Onderwerp: Re: [HECnet] Maximum number of L2 routers?
On 2015-02-28 21:21, Hans Vlems wrote:
Yeah of course you can have more than one L2 router in an area, didn't think of it :)
:-)
About the 10base5 segment, that was limited in length to 500 meters. Transceivers must be at least 2.5 meters apart, hence the 200 nodes. This was before a DELNI was invented. If my failing memory doesn't fail me that 200 node limit remained the same with Delni's.
But you were allowed to bridge several segments (using repeaters). I
think the maximum distance, including hops, between any two nodes had to
be within 1000m, but you could also do stars... You were not allowed to
have more than two repeaters I also seem to remember.
Johnny
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Van: Johnny Billquist
Verzonden: zaterdag 28 februari 2015 20:55
Aan: hecnet at Update.UU.SE
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Onderwerp: Re: [HECnet] Maximum number of L2 routers?
On 2015-02-28 20:51, Hans Vlems wrote:
64:-)?
You can definitely have more than one L2 router per area... :-)
I don't know for sure, as you probably have guessed...
There is an ncp executor parameter called maximum broadcast routers, default value 32 iirc.
Is there an architectural limit, depends on what you mean by ethernet segment. A 10base5 segment was limited to 200 nodes. 64 L2 routers might put a hefty broadcast load on it. On an extended ethernet LAN there is likely no technical limit.
Really? I have some vague memory of some limit of an ethernet segment,
but I can't recall any details now. Why 200?
Johnny
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Origineel bericht
Van: Jordi Guillaumes i Pons
Verzonden: zaterdag 28 februari 2015 20:37
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Onderwerp: [HECnet] Maximum number of L2 routers?
Hello, list,
I'm trying to remember what is the maximum number of area routers allowed in a DECNET Phase IV ethernet segment. Anyone of you have that information at hand?
On other news, the old macbook I was using as home server has died, after years of service beyond the call of duty. I'm setting up my stuff using several smallish ARM computers. To be specific, now I'm running a cubietruck and and Odroid-C1 (and a raspberry Pi as router/firewall). I'm having trouble with the net connectivity, so some yo-yo disconnects from area 7 should be expected. Not so hard as last sunday, but I'm still doing quite a lot of reboots.
BTW, the SG1 multinet link seems to be down again (unless it is a problem in my side, which is completely possible).
--
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
That's right, two repeaters between any two stations which gave you 1680 meters spanned distance. The extra 180 meters come from four transceiver cables, 45 m each.
The repeater rule btw is lifted by a bridge. And there is a maximum of 7 bridges between stations.
Not sure what you mean with a star configuration. The first (proprietary) glass fiber repeaters were star designs, was that what you meant?
DEC also sold remote bridges and repeaters. A glass fiber trunc connected either two remote repeaters or bridges or one of each. I forgot how long a fiber segment could be, 2500 m IIRC . That gave you some room to plan on a large site. Two remote repeaters counted as one in the two repeater rule.
Expensive stuff though. A Lanbridge 100 was 30.000 guilders in 1988. A remote bridge was even more expensive.
Verzonden vanaf mijn BlackBerry 10-smartphone.
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Van: Johnny Billquist
Verzonden: zaterdag 28 februari 2015 21:28
Aan: hecnet at Update.UU.SE
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Onderwerp: Re: [HECnet] Maximum number of L2 routers?
On 2015-02-28 21:21, Hans Vlems wrote:
Yeah of course you can have more than one L2 router in an area, didn't think of it :)
:-)
About the 10base5 segment, that was limited in length to 500 meters. Transceivers must be at least 2.5 meters apart, hence the 200 nodes. This was before a DELNI was invented. If my failing memory doesn't fail me that 200 node limit remained the same with Delni's.
But you were allowed to bridge several segments (using repeaters). I
think the maximum distance, including hops, between any two nodes had to
be within 1000m, but you could also do stars... You were not allowed to
have more than two repeaters I also seem to remember.
Johnny
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Verzonden: zaterdag 28 februari 2015 20:55
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Onderwerp: Re: [HECnet] Maximum number of L2 routers?
On 2015-02-28 20:51, Hans Vlems wrote:
64:-)?
You can definitely have more than one L2 router per area... :-)
I don't know for sure, as you probably have guessed...
There is an ncp executor parameter called maximum broadcast routers, default value 32 iirc.
Is there an architectural limit, depends on what you mean by ethernet segment. A 10base5 segment was limited to 200 nodes. 64 L2 routers might put a hefty broadcast load on it. On an extended ethernet LAN there is likely no technical limit.
Really? I have some vague memory of some limit of an ethernet segment,
but I can't recall any details now. Why 200?
Johnny
Verzonden vanaf mijn BlackBerry 10-smartphone.
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Van: Jordi Guillaumes i Pons
Verzonden: zaterdag 28 februari 2015 20:37
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Beantwoorden: hecnet at Update.UU.SE
Onderwerp: [HECnet] Maximum number of L2 routers?
Hello, list,
I'm trying to remember what is the maximum number of area routers allowed in a DECNET Phase IV ethernet segment. Anyone of you have that information at hand?
On other news, the old macbook I was using as home server has died, after years of service beyond the call of duty. I'm setting up my stuff using several smallish ARM computers. To be specific, now I'm running a cubietruck and and Odroid-C1 (and a raspberry Pi as router/firewall). I'm having trouble with the net connectivity, so some yo-yo disconnects from area 7 should be expected. Not so hard as last sunday, but I'm still doing quite a lot of reboots.
BTW, the SG1 multinet link seems to be down again (unless it is a problem in my side, which is completely possible).
--
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 2015-02-28 21:21, Hans Vlems wrote:
Yeah of course you can have more than one L2 router in an area, didn't think of it :)
:-)
About the 10base5 segment, that was limited in length to 500 meters. Transceivers must be at least 2.5 meters apart, hence the 200 nodes. This was before a DELNI was invented. If my failing memory doesn't fail me that 200 node limit remained the same with Delni's.
But you were allowed to bridge several segments (using repeaters). I think the maximum distance, including hops, between any two nodes had to be within 1000m, but you could also do stars... You were not allowed to have more than two repeaters I also seem to remember.
Johnny
Verzonden vanaf mijn BlackBerry 10-smartphone.
Origineel bericht
Van: Johnny Billquist
Verzonden: zaterdag 28 februari 2015 20:55
Aan: hecnet at Update.UU.SE
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Onderwerp: Re: [HECnet] Maximum number of L2 routers?
On 2015-02-28 20:51, Hans Vlems wrote:
64:-)?
You can definitely have more than one L2 router per area... :-)
I don't know for sure, as you probably have guessed...
There is an ncp executor parameter called maximum broadcast routers, default value 32 iirc.
Is there an architectural limit, depends on what you mean by ethernet segment. A 10base5 segment was limited to 200 nodes. 64 L2 routers might put a hefty broadcast load on it. On an extended ethernet LAN there is likely no technical limit.
Really? I have some vague memory of some limit of an ethernet segment,
but I can't recall any details now. Why 200?
Johnny
Verzonden vanaf mijn BlackBerry 10-smartphone.
Origineel bericht
Van: Jordi Guillaumes i Pons
Verzonden: zaterdag 28 februari 2015 20:37
Aan: HECnet Mailing List
Beantwoorden: hecnet at Update.UU.SE
Onderwerp: [HECnet] Maximum number of L2 routers?
Hello, list,
I'm trying to remember what is the maximum number of area routers allowed in a DECNET Phase IV ethernet segment. Anyone of you have that information at hand?
On other news, the old macbook I was using as home server has died, after years of service beyond the call of duty. I'm setting up my stuff using several smallish ARM computers. To be specific, now I'm running a cubietruck and and Odroid-C1 (and a raspberry Pi as router/firewall). I'm having trouble with the net connectivity, so some yo-yo disconnects from area 7 should be expected. Not so hard as last sunday, but I'm still doing quite a lot of reboots.
BTW, the SG1 multinet link seems to be down again (unless it is a problem in my side, which is completely possible).
--
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
Jordi, what made you ask the question in the first place, academic interest?
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Onderwerp: Re: [HECnet] Maximum number of L2 routers?
El 28/02/2015, a les 20:55, Johnny Billquist <bqt at softjar.se> va escriure:
On 2015-02-28 20:51, Hans Vlems wrote:
64:-)?
You can definitely have more than one L2 router per area... :-)
I don't know for sure, as you probably have guessed...
There is an ncp executor parameter called maximum broadcast routers, default value 32 iirc.
Is there an architectural limit, depends on what you mean by ethernet segment. A 10base5 segment was limited to 200 nodes. 64 L2 routers might put a hefty broadcast load on it. On an extended ethernet LAN there is likely no technical limit.
Really? I have some vague memory of some limit of an ethernet segment, but I can't recall any details now. Why 200?
Got it. The (virtual) Big Orange Wall comes to the rescue:
3.7.3.1 Maximum Number of Routers and End Nodes Allowed
Certain NCP command parameter values limit the number of routers and end nodes that can be configured on broadcast circuits.
Use the SET CIRCUIT command with the MAXIMUM ROUTERS parameter to set the maximum number of routers permitted on a particular Ethernet or FDDI circuit. The largest number of routers allowed on a LAN is 33, which is the default value of the MAXIMUM ROUTERS parameter. Note that the recommended limit on the number of routers on a single broadcast circuit is 10, because of the control traffic overhead (routing messages and system identification messages) involved. For example, the following command specifies that no more than five routers can exist on Ethernet circuit SVA-0:
NCP>SET CIRCUIT SVA-0 MAXIMUM ROUTERS 5
Use the SET EXECUTOR command with the MAXIMUM BROADCAST ROUTERS parameter to specify the maximum number of routing nodes that will be permitted on all Ethernet and FDDI circuits to which the local node is attached.
So it is a global maximum, for both L1 and L2 routers.
