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Hi All,
I have a single Domain DC and DNS is on same server Server name = DC.domain.com = 192.168.1.5 The users are divided in to four IP subnets: Subnet A - 192.168.1.1-62 Subnet B - 192.168.1.65-126 Subnet C - 192.168.1.129-190 Subnet D - 192.168.1.193-254 I have to finish following tasks: Task1: All the domain machines need to communicate with each other accept Subnet C Task2: DNS and DC will be on Subnet A Task3: How il routing happen? Please me i needed to finish this tasks ASAP. Thanks CK |
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#2 |
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Hébergeur: |
In news:1158143595.780294.214880@h48g2000cwc.googlegr oups.com,
chetan.kamra@gmail.com <chetan.kamra@gmail.com> typed: > Hi All, > > I have a single Domain DC and DNS is on same server > Server name = DC.domain.com = 192.168.1.5 > > The users are divided in to four IP subnets: > > Subnet A - 192.168.1.1-62 > Subnet B - 192.168.1.65-126 > Subnet C - 192.168.1.129-190 > Subnet D - 192.168.1.193-254 Those are not different subnets - they're different IP address 'ranges' in the same 192.168.1.0 one. What's the actual business/technical goal here? Knowing that might someone give you good advice. > > I have to finish following tasks: > > Task1: All the domain machines need to communicate with each other > accept Subnet C Presuming that C were actually a subnet, what is it supposed to have *in* it, and what's its purpose? > Task2: DNS and DC will be on Subnet A If you're going to have multiple subnets, you probably ought to have a DC & DNS & DHCP server in each subnet. > Task3: How il routing happen? No routing is required with the description you've provided, but if you were going to set up separate subnets, you could use routers, or switches configured with VLANs. > > Please me i needed to finish this tasks ASAP. Again, what's the ultimate goal here? > > > Thanks > CK |
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#3 |
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Hébergeur: |
This sounds like a homework question. But assuming these are actually
subnets separated by VLANs or something, you'd need a layer-3 switch or router between them. Router setup would be something like this: Subnet A | Subnet B Router < | Subnet C Subnet D Router interface A 192.168.1.1/26 Router interface B 192.168.65/26 Router interface C 192.168.129/26 Router interface D 192.168.193/26 Computers in each subnet would point to the local router interface as their default gateway. Assuming the DC/DNS server is 192.168.1.2 then you'd have to create an access-list and apply it to interface A, something like access-list 101 permit ip 192.168.128.0 0.0.0.191 host 192.168.1.2 access-list 101 deny ip 192.168.1.128 0.0.0.191 192.168.1.0 0.0.0.255 access-list 101 permit ip any any line 1 permits subnet C to route to the server line 2 prevents routing to any other host on the 192.168.1.0/24 network (access to the local subnet is not routed, so local traffic would still communicate). line 3 permits all other routing (assuming the router also has a default gateway for Internet). .....kurt <chetan.kamra@gmail.com> wrote in message news:1158143595.780294.214880@h48g2000cwc.googlegr oups.com... > Hi All, > > I have a single Domain DC and DNS is on same server > Server name = DC.domain.com = 192.168.1.5 > > The users are divided in to four IP subnets: > > Subnet A - 192.168.1.1-62 > Subnet B - 192.168.1.65-126 > Subnet C - 192.168.1.129-190 > Subnet D - 192.168.1.193-254 > > I have to finish following tasks: > > Task1: All the domain machines need to communicate with each other > accept Subnet C > Task2: DNS and DC will be on Subnet A > Task3: How il routing happen? > > Please me i needed to finish this tasks ASAP. > > > Thanks > CK > |
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#4 |
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Hébergeur: |
Thanks Guys
It ed alot to me. I am Difining my current network to all of you may be that will you understanding my goals. ISP----> Gateway Router -->LAN In lan LAN>> IP are 192.168.1.2 - 192.168.1.254 192.168.1.5 DC/DNS 192.168.1.50-75 >> Special Team Goals to achive. 1. Special team have to be isolated from Other network +have to be logged on DC at same time. 2. DNS wil host all IP request to all for whole network. Thanks CK |
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#5 |
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Hébergeur: |
"Lanwench [MVP - Exchange]"
<lanwench@heybuddy.donotsendme.unsolicitedmail.aty ahoo.com> wrote in message news:%23$CdBkz1GHA.4924@TK2MSFTNGP05.phx.gbl... > In news:1158143595.780294.214880@h48g2000cwc.googlegr oups.com, > chetan.kamra@gmail.com <chetan.kamra@gmail.com> typed: >> Hi All, >> >> I have a single Domain DC and DNS is on same server >> Server name = DC.domain.com = 192.168.1.5 >> >> The users are divided in to four IP subnets: > >> >> Subnet A - 192.168.1.1-62 >> Subnet B - 192.168.1.65-126 >> Subnet C - 192.168.1.129-190 >> Subnet D - 192.168.1.193-254 > > Those are not different subnets - they're different IP address 'ranges' in > the same 192.168.1.0 one. Lanwench MIGHT not be incorrect on this one, since those are probably subnets based on a 255.255.255.192 subnet mask. > What's the actual business/technical goal here? Knowing that might > someone give you good advice. > >> >> I have to finish following tasks: >> >> Task1: All the domain machines need to communicate with each other >> accept Subnet C > > Presuming that C were actually a subnet, what is it supposed to have *in* > it, and what's its purpose? It sounds like a homework or (very STUPID) test prep question. And it makes no sense for Subnet C to be part of the domain and NOT communicate. >> Task2: DNS and DC will be on Subnet A Not an issue, even which makes it sound even more like some homework or test prep question: Just put a router in between with 3 NICs and have all the machines use it as default gateway. Why 3 NIC in the router? No point in even connecting Subnet C if it is NOT going to communicate. <GRIN> > If you're going to have multiple subnets, you probably ought to have a DC > & DNS & DHCP server in each subnet. There is no particular reason for recommending this. Neither DCs NOR DNS are required on a per subnet basis, unless WAN lines are involved. One might expect a second DC and DNS in a real life scenario though -- merely for fault tolerance. >> Task3: How il routing happen? > > No routing is required with the description you've provided, but if you > were going to set up separate subnets, you could use routers, or switches > configured with VLANs. No, if they are four subnets then a router with (at least) 3 NICs is required. >> Please me i needed to finish this tasks ASAP. Chances are it is an attempt for us to do your homework. > Again, what's the ultimate goal here? Homework is my bet. -- Herb Martin, MCSE, MVP Accelerated MCSE http://www.LearnQuick.Com [phone number on web site] >> >> >> Thanks >> CK > > > |
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#6 |
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In news:uvHAO581GHA.4924@TK2MSFTNGP05.phx.gbl,
Herb Martin <news@LearnQuick.com> typed: > "Lanwench [MVP - Exchange]" > <lanwench@heybuddy.donotsendme.unsolicitedmail.aty ahoo.com> wrote in > message news:%23$CdBkz1GHA.4924@TK2MSFTNGP05.phx.gbl... >> In news:1158143595.780294.214880@h48g2000cwc.googlegr oups.com, >> chetan.kamra@gmail.com <chetan.kamra@gmail.com> typed: >>> Hi All, >>> >>> I have a single Domain DC and DNS is on same server >>> Server name = DC.domain.com = 192.168.1.5 >>> >>> The users are divided in to four IP subnets: >> >>> >>> Subnet A - 192.168.1.1-62 >>> Subnet B - 192.168.1.65-126 >>> Subnet C - 192.168.1.129-190 >>> Subnet D - 192.168.1.193-254 >> >> Those are not different subnets - they're different IP address >> 'ranges' in the same 192.168.1.0 one. > > Lanwench MIGHT not be incorrect on this one, since > those are probably subnets based on a 255.255.255.192 > subnet mask. Yep - you're right. I saw that in someone else's reply as well. Would've been ful if the OP had included the subnet mask. > > >> What's the actual business/technical goal here? Knowing that might >> someone give you good advice. >> >>> >>> I have to finish following tasks: >>> >>> Task1: All the domain machines need to communicate with each other >>> accept Subnet C >> >> Presuming that C were actually a subnet, what is it supposed to have >> *in* it, and what's its purpose? > > It sounds like a homework or (very STUPID) test prep question. <g> > > And it makes no sense for Subnet C to be part of the domain > and NOT communicate. > >>> Task2: DNS and DC will be on Subnet A > > Not an issue, even which makes it sound even more > like some homework or test prep question: > > Just put a router in between with 3 NICs and have all > the machines use it as default gateway. > > Why 3 NIC in the router? No point in even connecting Subnet > C if it is NOT going to communicate. <GRIN> > >> If you're going to have multiple subnets, you probably ought to have >> a DC & DNS & DHCP server in each subnet. > > There is no particular reason for recommending this. Neither > DCs NOR DNS are required on a per subnet basis, unless WAN > lines are involved. > > One might expect a second DC and DNS in a real life scenario > though -- merely for fault tolerance. Yes, and I was presuming a real-life scenario, I guess. > >>> Task3: How il routing happen? >> >> No routing is required with the description you've provided, but if >> you were going to set up separate subnets, you could use routers, or >> switches configured with VLANs. > > No, if they are four subnets then a router with (at least) 3 NICs > is required. Why not VLANs? I admit this isn't my strongest area, but I thought that was one thing VLANs could do... I bow to your expertise. > >>> Please me i needed to finish this tasks ASAP. > > Chances are it is an attempt for us to do your homework. > >> Again, what's the ultimate goal here? > > Homework is my bet. > > >>> >>> >>> Thanks >>> CK |
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#7 |
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>> No, if they are four subnets then a router with (at least) 3 NICs
>> is required. > > Why not VLANs? I admit this isn't my strongest area, but I thought that > was one thing VLANs could do... I bow to your expertise. A VLAN switch is a form of (configuarable) router. Each individual VLAN is effectively on a separate NIC; VLAN switches include the ability to DEFINE by the admin which ports are BRIDGED (same VLAN) and which are ROUTED (different VLAN and different broadcast domain). A VLAN Switch is essentially a "routed group of bridges" but all contained within one box and configurable in software. >>>> Please me i needed to finish this tasks ASAP. >> >> Chances are it is an attempt for us to do your homework. >> >>> Again, what's the ultimate goal here? >> >> Homework is my bet. -- Herb Martin, MCSE, MVP Accelerated MCSE http://www.LearnQuick.Com [phone number on web site] "Lanwench [MVP - Exchange]" <lanwench@heybuddy.donotsendme.unsolicitedmail.aty ahoo.com> wrote in message news:ulged8$1GHA.2196@TK2MSFTNGP06.phx.gbl... > In news:uvHAO581GHA.4924@TK2MSFTNGP05.phx.gbl, > Herb Martin <news@LearnQuick.com> typed: >> "Lanwench [MVP - Exchange]" >> <lanwench@heybuddy.donotsendme.unsolicitedmail.aty ahoo.com> wrote in >> message news:%23$CdBkz1GHA.4924@TK2MSFTNGP05.phx.gbl... >>> In news:1158143595.780294.214880@h48g2000cwc.googlegr oups.com, >>> chetan.kamra@gmail.com <chetan.kamra@gmail.com> typed: >>>> Hi All, >>>> >>>> I have a single Domain DC and DNS is on same server >>>> Server name = DC.domain.com = 192.168.1.5 >>>> >>>> The users are divided in to four IP subnets: >>> >>>> >>>> Subnet A - 192.168.1.1-62 >>>> Subnet B - 192.168.1.65-126 >>>> Subnet C - 192.168.1.129-190 >>>> Subnet D - 192.168.1.193-254 >>> >>> Those are not different subnets - they're different IP address >>> 'ranges' in the same 192.168.1.0 one. >> >> Lanwench MIGHT not be incorrect on this one, since >> those are probably subnets based on a 255.255.255.192 >> subnet mask. > > Yep - you're right. I saw that in someone else's reply as well. Would've > been ful if the OP had included the subnet mask. >> >> >>> What's the actual business/technical goal here? Knowing that might >>> someone give you good advice. >>> >>>> >>>> I have to finish following tasks: >>>> >>>> Task1: All the domain machines need to communicate with each other >>>> accept Subnet C >>> >>> Presuming that C were actually a subnet, what is it supposed to have >>> *in* it, and what's its purpose? >> >> It sounds like a homework or (very STUPID) test prep question. > > <g> > > >> >> And it makes no sense for Subnet C to be part of the domain >> and NOT communicate. >> >>>> Task2: DNS and DC will be on Subnet A >> >> Not an issue, even which makes it sound even more >> like some homework or test prep question: >> >> Just put a router in between with 3 NICs and have all >> the machines use it as default gateway. >> >> Why 3 NIC in the router? No point in even connecting Subnet >> C if it is NOT going to communicate. <GRIN> >> >>> If you're going to have multiple subnets, you probably ought to have >>> a DC & DNS & DHCP server in each subnet. >> >> There is no particular reason for recommending this. Neither >> DCs NOR DNS are required on a per subnet basis, unless WAN >> lines are involved. >> >> One might expect a second DC and DNS in a real life scenario >> though -- merely for fault tolerance. > > Yes, and I was presuming a real-life scenario, I guess. > >> >>>> Task3: How il routing happen? >>> >>> No routing is required with the description you've provided, but if >>> you were going to set up separate subnets, you could use routers, or >>> switches configured with VLANs. >> >> >> >>>> >>>> >>>> Thanks >>>> CK > > > |
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Hébergeur: |
> Why not VLANs? I admit this isn't my strongest area, but I thought that
> was one thing VLANs could do... I bow to your expertise. IMHO, VLANs would be the way to go. Otherwise the separation between subnets is purely logical. Anybody could just change their IP address, or introduce a laptop with an IP address on another subnet and be connected. VLANs contain broadcasts and prevent any kind of connection between subnets other than through the router (which can be locked down as tightly as local management sees fit). If I were designing this for a client, I would probably sell them managed layer-2 switches for subnets B-D and a layer-3 switch for Subnet A. Traffic from the other subnets could be trunked through the uplink port and routed at the L-3 switch. Quick to set up, central management, fewer devices to configure, plus L-3 switches will forward gigabit traffic at wire-speed unlike plain vanilla routers. ....kurt |
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"Kurt" <lorentzenkurt@nospam.hotmail.com> wrote in message
news:12gir3fpjhsj117@corp.supernews.com... >> Why not VLANs? I admit this isn't my strongest area, but I thought that >> was one thing VLANs could do... I bow to your expertise. > > IMHO, VLANs would be the way to go. Otherwise the separation between > subnets is purely logical. No, subnets in IP are far more than purely logical. They practically always represent a distinct "Broadcast domain" (area in which a broadcast will freely propagate. If two machines are on the same broadcast domain they are (practically*) always on the same subnet, and conversely if they are not on the same broadcast domain then they are not in the same broadcast domain. [* It is theorectically possible to have multiple subnets on the same 'wire' or 'broacast domain' but this is not a common practice in modern networks -- and still requires some special configuration.] The real problem is many the incomplete understand of of VLANs switches, and switches in general, by many people. One cannot understand VLANs (or any switches) completely without first understanding the differences and features of both Routers and Bridges -- we can call the features something else but switches are merely "switching" combined with either the Bridge or Router concept, or in modern devices a hybrid of all three concepts. VLANs switches allow the admin to (easily) redefine each bridged segment to include arbitrary connections to the switch, and thus map a "set of computers" to either one bridged broadcast domain OR another to which routing is required. Routed segments REQUIRE different IP subnets while EACH bridged segment typically (and all modern networks) place all of the machines on the same subnet. > Anybody could just change their IP address, or introduce a laptop with an > IP address on another subnet and be connected. This really has nothing specific to do with VLANs per se. It is a feature of whether that wiring segment is either Bridged or Routed. The KEY to a VLAN switch is the "area" or the "component network cables" which are BRIDGED vs. ROUTED can be configured by the Admin using switch-commands. > VLANs contain broadcasts and prevent any kind of connection between > subnets other than through the router (which can be locked down as tightly > as local management sees fit). If I were designing this for a client, I > would probably sell them managed layer-2 switches for subnets B-D and a > layer-3 switch for Subnet A. Traffic from the other subnets could be > trunked through the uplink port and routed at the L-3 switch. Quick to set > up, central management, fewer devices to configure, plus L-3 switches will > forward gigabit traffic at wire-speed unlike plain vanilla routers. > The above has little to do with understanding the basic concepts that are being confused here -- and detracts from keeping the explanation simple and accurate. -- Herb Martin, MCSE, MVP Accelerated MCSE http://www.LearnQuick.Com [phone number on web site] > ...kurt > |
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Hébergeur: |
>No, subnets in IP are far more than purely logical.
>They practically always represent a distinct "Broadcast >domain" (area in which a broadcast will freely propagate). Not if they're on the same wire. Although IP broadcasts will be discarded at the layer-3 level, Ethernet broadcasts propogate to every node in the broadcast domain (not to be confused with collision domain), regardless of IP subnet. > If two machines are on the same broadcast domain they > are (practically*) always on the same subnet, and conversely > if they are not on the same broadcast domain then they are > not in the same broadcast domain. Once again, does not apply if they are on the same wire. > [* It is theorectically possible to have multiple subnets on > the same 'wire' or 'broacast domain' but this is not a common > practice in modern networks -- and still requires some special > configuration.] requires no special configuration at all. Get a switch, plug 4 computers into it. Put 2 on one IP subnet and two on another. Computers on the same IP subnet can talk, computers on disparate IP subnets cannot (at layer-3). But if you sniff the wire at any computer, you'll see arp broadcasts and such from every computer. > The real problem is many the incomplete understand of of > VLANs switches, and switches in general, by many people. > One cannot understand VLANs (or any switches) completely > without first understanding the differences and features of > both Routers and Bridges -- we can call the features something > else but switches are merely "switching" combined with either > the Bridge or Router concept, or in modern devices a hybrid > of all three concepts. True, but I must say that I don't fall into that category. As the senior engineer/primary designer of a metro ring infrastructure, I live and breathe VLANs and routers every day of my life. They are what make shared ethernet infrastructures work. > VLANs switches allow the admin to (easily) redefine each > bridged segment to include arbitrary connections to the switch, > and thus map a "set of computers" to either one bridged > broadcast domain OR another to which routing is required. VLANS can exist as port based, protocol based even application based on really sophisticated multi-layer switches. They can live on a single switch, or span multiple switches, indeed multiple cities and service providers (although the latter is uncommon). Switches create separate collision domains. VLANs create separate broadcast domains. Communication between VLANS is not possible unless it is routed (OK, you could bridge it, but that would defeat the whole purpose). > Routed segments REQUIRE different IP subnets while EACH > bridged segment typically (and all modern networks) place all > of the machines on the same subnet. That's the way it usually works, but the OP does not mention anything but IP subnets - purely logical separation. > >> Anybody could just change their IP address, or introduce a laptop with an >> IP address on another subnet and be connected. > This really has nothing specific to do with VLANs per se. It has nothing to do with a VLAN at all as a standalone statement. Incoroprating VLANS into a single physical infrastructure enhances the security and prevents broadcast traffic between virtual segments. It really comes down to what the OP was driving at. A | | | | ------- ROUTER ------- | | Those are two physical segments (and must be configured as different logical subnets in order to route traffic between). B | | | 192.168.1.x /24 --------------- | | | 192.168.2.x/24 If a plain 'ole $99 switch is used, you have two logical subnets but one broadcast domain. I could still stick a 2 port router on there and route traffic between logical subnets. But if I use a managed switch and create two VLANs, I effectively have the same separation as "A". > It is a feature of whether that wiring segment is either Bridged or > Routed. Or virtually segmented and routed. > > The KEY to a VLAN switch is the "area" or the "component > network cables" which are BRIDGED vs. ROUTED can be > configured by the Admin using switch-commands. > >> VLANs contain broadcasts and prevent any kind of connection between >> subnets other than through the router (which can be locked down as >> tightly as local management sees fit). If I were designing this for a >> client, I would probably sell them managed layer-2 switches for subnets >> B-D and a layer-3 switch for Subnet A. Traffic from the other subnets >> could be trunked through the uplink port and routed at the L-3 switch. >> Quick to set up, central management, fewer devices to configure, plus L-3 >> switches will forward gigabit traffic at wire-speed unlike plain vanilla >> routers. >> > > The above has little to do with understanding the basic concepts that > are being confused here -- and detracts from keeping the explanation > simple and accurate. Perhaps, but the OP only mentioned IP subnets, no physical separation. Still, none of the answers provided a workable solution . "Why 3 NIC in the router? No point in even connecting Subnet C if it is NOT going to communicate. <GRIN>" Subnet C DOES have to communicate - With the DNS server / DC in subnet A - but not with computers in other subnets. If this is a homework question it is , like most, poorly written. The "right" answer is probably to put a rotuer between Subnets A, B, and D and leave subnet C all to itself. Of course the domain would not function on subnet C because it couldn't contact the DC or DNS server. So I proposed a solution that would allow subnet C to talk to the DC/DNS server but not communicate with other computers. The VLAN thing was in response to Lanwrench's post and took it a bit further. But I stand my ground on these points: IP subnets are purely logical things. They can be configured without regard to the physical device or how it is cabled. Routers can route between IP subnets on the same physical segment or on separate physical segments, or on separate virtual segments. ....kurt |
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"Kurt" <lorentzenkurt@nospam.hotmail.com> wrote in message
news:12gk9n8d695gc26@corp.supernews.com... > >No, subnets in IP are far more than purely logical. > > >They practically always represent a distinct "Broadcast >>domain" (area in which a broadcast will freely propagate). > > Not if they're on the same wire. That is precisely WHERE broadcasts propagate freely without any assistance: On the same wire. > Although IP broadcasts will be discarded at the layer-3 level, Ethernet > broadcasts propogate to every node in the broadcast domain (not to be > confused with collision domain), regardless of IP subnet. You keep introducing irrelevant issues that have little or (absolutely) nothing to do with understanding the issues under discussion, especially bridges, switches, routers, VLANs, and IP Subnets. >> If two machines are on the same broadcast domain they >> are (practically*) always on the same subnet, and conversely >> if they are not on the same broadcast domain then they are >> not in the same broadcast domain. > > > Once again, does not apply if they are on the same wire. Which "they"? Multi-nets are discussed below if that is your quibble (although still largely irrelevant) but otherwise the above has no meaning here. >> [* It is theorectically possible to have multiple subnets on >> the same 'wire' or 'broacast domain' but this is not a common >> practice in modern networks -- and still requires some special >> configuration.] > > requires no special configuration at all. Get a switch, plug 4 computers > into it. Put 2 on one IP subnet and two on another. Computers on the same > IP subnet can talk, computers on disparate IP subnets cannot (at layer-3). > But if you sniff the wire at any computer, you'll see arp broadcasts and > such from every computer. I was trying to you but you apparently have a very poor true understanding of switches yet do not wish to learn. See next paragraphs... >> The real problem is many the incomplete understand of of >> VLANs switches, and switches in general, by many people. > >> One cannot understand VLANs (or any switches) completely >> without first understanding the differences and features of >> both Routers and Bridges -- we can call the features something >> else but switches are merely "switching" combined with either >> the Bridge or Router concept, or in modern devices a hybrid >> of all three concepts. > > True, but I must say that I don't fall into that category. As the senior > engineer/primary designer of a metro ring infrastructure, I live and > breathe VLANs and routers every day of my life. They are what make shared > ethernet infrastructures work. You really would benefit -- if only in explaining it to others -- if you understood the basics better then. I will you if you wish to learn.... >> VLANs switches allow the admin to (easily) redefine each >> bridged segment to include arbitrary connections to the switch, >> and thus map a "set of computers" to either one bridged >> broadcast domain OR another to which routing is required. > >> The KEY to a VLAN switch is the "area" or the "component >> network cables" which are BRIDGED vs. ROUTED can be >> configured by the Admin using switch-commands. -- Herb Martin, MCSE, MVP Accelerated MCSE http://www.LearnQuick.Com [phone number on web site] |
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Hébergeur: |
> You really would benefit -- if only in explaining it to others -- if > you understood the basics better then. > > I will you if you wish to learn.... I understand the basics extremely well. I think you need to pick up a Cisco book and re-read if your understanding is different. Here's a very basic tutorial (for anyone who cares to know) on how VLANs work: First, let's all agree to use the standard, which is now 802.1q. Old Cisco ISL VLANS are history. Newer Cisco switches don't even support ISL anymore. Some cheapo switches also support local "port-based" VLANs, but those do not use tagging, nor are they trunkable to other switches. The following explains "port-centric" 802.1q VLANs, by far the most widely used application. Also let's pre-define "traffic", "communication", etc as TCP/IP on an ethernet network. 1. A switch is configured with one vlan or many vlans. Ports are added to those VLANs as either "tagged" or "untagged" (this is RFC language. Cisco uses their own terminology "Access port" = untagged and "trunk port" = tagged - they always have to be different). Yes, there are variations, but this will stick to the very basics. 2. An "untagged" port accepts only ethernet frames that do not already carry a VLAN tag. When frames enter untagged ports, they are given a tag with the VLAN ID of that port's membership. 3. A "tagged" port accepts only frames that already have a tag. A tagged port can be configured to be a member of 1 or more vlans, and are typically used for inter-switch VLAN "trunking", where traffic from multiple VLANS can travel across a single uplink (This is how my traffic from many clients is carried.across a single metro-ring infrastructure. It is also how multiple T1, Voice and other telecom traffic travels across a single pair of fiber optic cables. Telephone terminology is different, but the concept is exactly the same). 4. When a frame is to be delivered, it may only exit the switch (egress) on a port that is a member of the VLAN that it is tagged with. If that port is an "untagged" port, then the VLAN tag is stripped from the frame on egress - this is normally for delivery to an end user station. If that port is a "tagged" port, the VLAN tag stays with the frame to it's next destination - usually another switch, and once again will only be accepted by another tagged port with membership in that vlan. 5. All types of ethernet frames are tagged, including broadcast frames. That is how broadcasts are contained within a single VLAN infrastructure. All hosts on the VLAN hear broadcasts on that VLAN. Hosts on other VLANS do not. 6. Since frames do not propogate onto ports that are members of other VLANs, communication is impossible between hosts on different VLANS, regardless of the logical network (ip subnet) they are configured for. 7. If traffic is to be exchanged between VLANs, a router is required, and different logical subnets must be defined for each VLAN because that is what routers do - they route between subnets. (actually my devices are multi-layer Foundry Networks BI-4000s, so they handle the routing as well). Here are a couple of examples: 192.168.1.1 192.168.1.2 Computer A Computer B | | VL1 VL1 --------------------------- | SWITCH | --------------------------- VL2 VL2 | | Computer C Computer D 192.168.1.3 192.168.1.4 Better diagram here : http://65.243.151.82/a.html In the example above, computer C can ping computer D and Computer A can ping computer B (and vice versa of course). But computers A and B cannot ping computers B or C even though they are in the same IP subnet (all have /24 netmask), because they are on different VLANS. ----------------------------------------------------------------- 192.168.1.1 192.168.1.2 Computer A Computer B | | VL1 VL1 --------------------------- | SWITCH | --------------------------- VL2 uplink VL2 | tag VL 1 & 2 | | | | Computer C | Computer D 192.168.1.3 | 192.168.1.4 | 192.168.1.5 | 192.168.1.6 Computer E | Computer F | | | | tag VL1 & 2 | VL1 | VL1 --------------------------- | SWITCH | --------------------------- VL2 VL2 | | Computer G Computer H 192.168.1.7 192.168.1.8 Better diagram here : http://65.243.151.82/b.html Going a little further (2 switches) in the above example, in addition to the connectivity (or lack thereof) in the first example, Computers G and H can communicate with computers C & D, but not A, B, E or F. Computers E and F can communicate with A and B, but not C, D, E or F. This is all true, even though all computers are on the same IP (logical) subnet. ----------------------------------------------------------------- 192.168.1.1 192.168.1.2 Computer A Computer B | | --------------------------- | Dumb switch no Vlans | --------------------------- | | Computer C Computer D 192.168.2.1 192.168.2.2 Better diagram here : http://65.243.151.82/c.html Here Computers A and B can ping each other, but not C or D, because even though they are connected to the same switch (broadcast domain), they are in different IP subnets. ----------------------------------------------------------------- 192.168.1.1 192.168.1.2 G/W 1.10 Computer A Computer B | | --------------------------- --------------- | |--|-192.168.1.10 | | Dumb switch no Vlans | | Router | | |--|-192.168.2.10 | --------------------------- ---------------- | | Computer C Computer D 192.168.2.1 192.168.2.2 G/W 2.10 Better diagram here : http://65.243.151.82/e.html Now, with the gateways pointed at the router which has an IP interface on each subnet, all computers can contact each other. Here computers A and B will communicate directly and Computer A will, for instance, communicate with C through the router. But if you changed computer C's IP address to 192.168.1.3, it would no longer have to communicate with A via the router. You could take the router away and A-C would still communicate in the same manner as A-B. ----------------------------------------------------------------- 192.168.1.1 192.168.1.2 G/W 1.10 Computer A Computer B | | VL1 VL1 --------------------------- --------------- | |--|-192.168.1.10 | | SWITCH | | Router | | |--|-192.168.2.10 | --------------------------- ---------------- VL2 VL2 | | Computer C Computer D 192.168.2.1 192.168.2.2 G/W 2.10 Better diagram here : http://65.243.151.82/d.html And lastly, as with the previous example with the gateways set to a router the has an IP interface on each subnet, all computers can contact each other. Here computers A and B will communicate directly and Computer A will, for instance, communicate with C through the router. The difference is that if you changed computer C's IP address to 192.168.1.3, you could block communication with VLAN 1 at the router with an access-list. And, if you took the router away A-C communication is no longer possible. Believe me, I know what I'm talking about here. I've spent the last 5 years building this exact type of infrastructure from the ground up, albeit a tad more complex. But the fundamentals are the same. If you think I'm wrong, set it up and give it a try. I have - hundreds of times. Here are some links to some vlan info and basic layer-2 stuff. http://www.inetdaemon.com/tutorials/...an/index.shtml http://www.wi-fiplanet.com/tutorials...le.php/3577261 http://www.enterasys.com/support/man...%20tutorial%22 I liked this onethe best http://www.networkworld.com/news/tec.../0305tech.html ...kurt |
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"Kurt" <lorentzenkurt@nospam.hotmail.com> wrote in message
news:12gmh6bj81rdv34@corp.supernews.com... > First, let's all agree to use the standard, which is now 802.1q. Old Cisco > ISL VLANS are history. Newer Cisco switches don't even support ISL > anymore. Some cheapo switches also support local "port-based" VLANs, but > those do not use tagging, nor are they trunkable to other switches. The > following explains "port-centric" 802.1q VLANs, by far the most widely > used application. Also let's pre-define "traffic", "communication", etc as > TCP/IP on an ethernet network. No, none of that complication is necessary IF you had really understood the basics, not made several mistakes, overcomplicated it, tried to brag about how experienced you are, and then tried to hide behind obfuscation. I am never impressed when someone tries to justify their technical inadequacy by giving their resume: "True, but I must say that I don't fall into that category. As the senior engineer/primary designer of a metro ring infrastructure, I live and breathe VLANs and routers every day of my life." You are wasting my time at this point and you have already confused the issue for those trying to learn and understand networking correctly. -- Herb Martin, MCSE, MVP Accelerated MCSE http://www.LearnQuick.Com [phone number on web site] |
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I wasn't trying to hide behind anything, herb. I just can't abide when
someone tries to make me out to be some kind of loser who doesn't know my business. I'll go head to head with you any day in a real-life set-it-up-and-make-it-work situation. I've never claimed to be the sharpest pencil in the box, and I've learned a lot from your posts in the past. But I DO know networking from the root and fundamental levels up. I'm not a hardware engineer, so I can't tell you how the circuitry inside the routers, NICs and switches do their magic. But as far as designing, installing, and configuring a network, I know my stuff ! I'm sure you have a better handle on many things than I do, but not on this subject. Yes, I did make some cut and paste errors in the post. They are corrected on the links. Come th rhink of it, that's something I really COULD use some with - writing (typing too). Cheers, ....kurt "Herb Martin" <news@LearnQuick.com> wrote in message news:uZgbUWU2GHA.1292@TK2MSFTNGP03.phx.gbl... > "Kurt" <lorentzenkurt@nospam.hotmail.com> wrote in message > news:12gmh6bj81rdv34@corp.supernews.com... >> First, let's all agree to use the standard, which is now 802.1q. Old >> Cisco ISL VLANS are history. Newer Cisco switches don't even support ISL >> anymore. Some cheapo switches also support local "port-based" VLANs, but >> those do not use tagging, nor are they trunkable to other switches. The >> following explains "port-centric" 802.1q VLANs, by far the most widely >> used application. Also let's pre-define "traffic", "communication", etc >> as TCP/IP on an ethernet network. > > No, none of that complication is necessary IF you had really > understood the basics, not made several mistakes, overcomplicated > it, tried to brag about how experienced you are, and then tried to > hide behind obfuscation. > > I am never impressed when someone tries to justify their technical > inadequacy by giving their resume: > > "True, but I must say that I don't fall into that category. As the > senior > engineer/primary designer of a metro ring infrastructure, I live and > breathe > VLANs and routers every day of my life." > > You are wasting my time at this point and you have already confused > the issue for those trying to learn and understand networking correctly. > > > -- > Herb Martin, MCSE, MVP > Accelerated MCSE > http://www.LearnQuick.Com > [phone number on web site] > > |
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"Kurt" <lorentzenkurt@nospam.hotmail.com> wrote in message
news:12gn1rklotg357@corp.supernews.com... >I wasn't trying to hide behind anything, herb. I just can't abide when >someone tries to make me out to be some kind of loser who doesn't know my >business. Does that happen to you a lot? I certainly wasn't trying to make you out a loser (only you can do that yourself) but I will correct you if you make technical errors AND in the process are confusing those trying to learn. So don't do that anymore. > I'll go head to head with you any day in a real-life > set-it-up-and-make-it-work situation. I've never claimed to be the > sharpest pencil in the box, and I've learned a lot from your posts in the > past. But I DO know networking from the root and fundamental levels up. Then you have no excuse for such elementary errors -- whether you truly misunderstand or were just unable to explain how things work. You claimed experience suggests you SHOULD know better. I am always much tougher on those who are beginners than those who claim they know what they poorly understand. > I'm not a hardware engineer, so I can't tell you how the circuitry inside > the routers, NICs and switches do their magic. And that was always PART of my major point: You do not need to be a "hardware engineer" to understand IP, nor to understand routing and bridging. They are simple subjects if presented simply. No one can fully understand Switching in general and VLANs in particular with with an understanding of routing and bridging but it amazes me how many people seem to try. These are actually very simple subjects and in fact are better understood simply without reference to specific network hardware or any of the complexities of "network hardward engineering". > But as far as designing, installing, and configuring a network, I know my > stuff ! I'm sure you have a better handle on many things than I do, but > not on this subject. Yes, I did make some cut and paste errors in the > post. They are corrected on the links. Then when you figure that out -- stop arguiing. It's only when people argue BEYOND their mistakesm, rather than admitting and correcting them, that they begin to sound truly foolish. Everyone has to learn -- and their is no shame in being uninformed, but anytime we argue despite the facts we are not ing nor are we learning. > Come th rhink of it, that's something I really COULD use some with - > writing (typing too). I never criticize anyone's typing as long as the words can be decyphered. Seldom their grammar or English either. I personally type these notes as stream of consciousness, much like a conversation except we have to wait days or hours for a response and thus it is very easy to be misunderstood and for tones to be misinterpreted. As to typing (serious suggestion): Any good typing tutor works wonders. Even today I still use one regularly to counteract the bad habits I would otherwise fall into more deeply. Mavis Beacon and Tux Typing Tutor are my current favorites. -- Herb Martin, MCSE, MVP Accelerated MCSE http://www.LearnQuick.Com [phone number on web site] > Cheers, > ...kurt > > > "Herb Martin" <news@LearnQuick.com> wrote in message > news:uZgbUWU2GHA.1292@TK2MSFTNGP03.phx.gbl... >> "Kurt" <lorentzenkurt@nospam.hotmail.com> wrote in message >> news:12gmh6bj81rdv34@corp.supernews.com... >>> First, let's all agree to use the standard, which is now 802.1q. Old >>> Cisco ISL VLANS are history. Newer Cisco switches don't even support ISL >>> anymore. Some cheapo switches also support local "port-based" VLANs, but >>> those do not use tagging, nor are they trunkable to other switches. The >>> following explains "port-centric" 802.1q VLANs, by far the most widely >>> used application. Also let's pre-define "traffic", "communication", etc >>> as TCP/IP on an ethernet network. >> >> No, none of that complication is necessary IF you had really >> understood the basics, not made several mistakes, overcomplicated >> it, tried to brag about how experienced you are, and then tried to >> hide behind obfuscation. >> >> I am never impressed when someone tries to justify their technical >> inadequacy by giving their resume: >> >> "True, but I must say that I don't fall into that category. As the >> senior >> engineer/primary designer of a metro ring infrastructure, I live and >> breathe >> VLANs and routers every day of my life." >> >> You are wasting my time at this point and you have already confused >> the issue for those trying to learn and understand networking correctly. >> >> >> -- >> Herb Martin, MCSE, MVP >> Accelerated MCSE >> http://www.LearnQuick.Com >> [phone number on web site] >> >> > > |
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My final point on this issue. I have a lot of respect for your knowledge. My approach is different than yours. As I said, the VLAN thing was not started by me. It was in response to Lanwrench's question about VLANS. >A VLAN switch is a form of (configuarable) router. Your statement is just plain wrong. A "VLAN Switch" is not a router at all. I corrected the error without pointing out that you were in error (I try not to make a point of bringing attention to other's errors, just post the correction). >"A VLAN Switch is essentially a "routed group of bridges" >but all contained within one box and configurable in software." This is fundamentally incorrect. A Layer-3 switch that ALSO has dot1q capability can do both, but routing is a layer-3 function and VLANs are layer-2. Each can exist and function on it's own without the other. > It's only when people argue BEYOND their mistakesm, rather than > admitting and correcting them, that they begin to sound truly foolish. Are you big enough to take your own advice? Can you show me where I made a technical error (other than improperly edited cut and pastes that I do apologize for)? > Everyone has to learn -- and their is no shame in being > uninformed, but anytime we argue despite the facts we > are not ing nor are we learning. Agreed. > Mavis Beacon and Tux Typing Tutor are my current favorites. Is Tux Linux? I'll Google. ....kurt |
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"Kurt" <lorentzenkurt@nospam.hotmail.com> wrote in message news:12gr5a8r0shdheb@corp.supernews.com... > > My final point on this issue. I have a lot of respect for your knowledge. > My approach is different than yours. As I said, the VLAN thing was not > started by me. It was in response to Lanwrench's question about VLANS. > >>A VLAN switch is a form of (configuarable) router. > > Your statement is just plain wrong. A "VLAN Switch" is not a router at > all. I corrected the error without pointing out that you were in error (I > try not to make a point of bringing attention to other's errors, just post > the correction). Then you have thoroughly misunderstood VLANs switches. There purpose and implementation. -- Herb Martin, MCSE, MVP Accelerated MCSE http://www.LearnQuick.Com [phone number on web site] > >>"A VLAN Switch is essentially a "routed group of bridges" >>but all contained within one box and configurable in software." > > This is fundamentally incorrect. A Layer-3 switch that ALSO has dot1q > capability can do both, but routing is a layer-3 function and VLANs are > layer-2. Each can exist and function on it's own without the other. > >> It's only when people argu |