How do VLANs work?

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Virtual LANs (VLANs) are an abstraction to permit a single physical network to emulate the functionality of multiple parallel physical networks. This is handy because there may be situations where you need the functionality of multiple parallel physical networks but you’d rather not spend the money on buying parallel hardware. I’ll be speaking about Ethernet VLANs in this answer (even though other networking technologies can support VLANs) and I won’t be diving deeply into every nuance.

A Contrived Example and a Problem

As a purely contrived example scenario, imagine you own an office building that you lease to tenants. As a benefit of the lease, each tenant will get live Ethernet jacks in each room of the office. You buy a Ethernet switch for each floor, wire them up to jacks in each office on that floor, and wire all the switches together.
Initially, you lease space to two different tenants– one on the floor 1 and one on 2. Each of these tenants configures their computers w/ static IPv4 addresses. Both tenants use different TCP/IP subnets and everything seems to work just fine.

Later, a new tenant rents half of floor 3 and brings up one of these new-fangled DHCP servers. Time passes and the 1st floor tenant decides to jump on the DHCP bandwagon, too. This is the point when things start to go awry. The floor 3 tenants report that some of their computers are getting “funny” IP addresses from a machine that isn’t their DHCP server. Soon, the floor 1 tenants report the same thing.

DHCP is a protocol that takes advantage of the broadcast capability of Ethernet to allow client computers to obtain IP addresses dynamically. Because the tenants are all sharing the same physical Ethernet network they share the same broadcast domain. A broadcast packet sent from any computer in the network will flood out all the switch ports to every other computer. The DHCP servers on floors 1 and 3 will receive all requests for IP address leases and will, effectively, duel to see who can answer first. This is clearly not the behavior you intend your tenants to experience. This is the behavior, though, of a “flat” Ethernet network w/o any VLANs.

Worse still, a tenant on floor 2 acquires this “Wireshark” software and reports that, from time to time, they see traffic coming out of their switch that references computers and IP addresses that they’ve never heard of. One of their employees has even figured out that he can communicate with these other computers by changing the IP address assigned to his PC from 192.168.1.38 to 192.168.0.38! Presumably, he’s just a few short steps away from performing “unauthorized pro-bono system administration services” for one of the other tenants. Not good.

Potential Solutions

You need a solution! You could just pull the plugs between the floors and that would cut off all unwanted communication! Yeah! That’s the ticket…

That might work, except that you have a new tenant who will be renting half of the basement and the unoccupied half of floor 3. If there isn’t a connection between the floor 3 switch and the basement switch the new tenant won’t be able to get communication between their computers that will be spread around both of their floors. Pulling the plugs isn’t the answer. Worse still, the new tenant is bringing yet anotherone of these DHCP servers!

You flirt with the idea of buying physically separate sets of Ethernet switches for each tenant, but seeing as how your building has 30 floors, any of which can be subdivided up to 4 ways, the potential rats nest of floor-to-floor cables between massive numbers of parallel Ethernet switches could be a nightmare, not to mention expensive. If only there was a way to make a single physical Ethernet network act like it was multiple physical Ethernet networks, each with its own broadcast domain.

VLANs to the Rescue

VLANs are an answer to this messy problem. VLANs permit you to subdivide an Ethernet switch into logically disparate virtual Ethernet switches. This allows a single Ethernet switch to act as though it’s multiple physical Ethernet switches. In the case of your subdivided floor 3, for example, you could configure your 48 port switch such that the lower 24 ports are in a given VLAN (which we’ll call VLAN 12) and the higher 24 ports are in a given VLAN (which we’ll call VLAN 13). When you create the VLANs on your switch you’ll have to assign them some type of VLAN name or number. The numbers I’m using here are mostly arbitrary, so don’t worry about what specific numbers I choose.

Once you’ve divided the floor 3 switch into VLANs 12 and 13 you find that the new floor 3 tenant can plug in their DHCP server to one of the ports assigned to VLAN 13 and a PC plugged into a port assigned to VLAN 12 doesn’t get an IP address from the new DHCP server. Excellent! Problem solved!

Oh, wait… how do we get that VLAN 13 data down to the basement?

VLAN Communication Between Switches

Your half-floor 3 and half-basement tenant would like to connect computers in the basement to their servers on floor 3. You could run a cable directly from one of the ports assigned to their VLAN in the floor 3 switch to the basement and life would be good, right?

In the early days of VLANs (pre-802.1Q standard) you might do just that. The entire basement switch would be, effectively, part of VLAN 13 (the VLAN you’ve opted to assign to the new tenant on floor 3 and the basement) because that basement switch would be “fed” by a port on floor 3 that’s assigned to VLAN 13.

This solution would work until you rent the other half of the basement to your floor 1 tenant who also wants to have communication between their 1st floor and basement computers. You could split the basement switch using VLANs (into, say, VLANS 2 and 13) and run a cable from floor 1 to a port assigned to VLAN 2 in the basement, but you better judgement tells you that this could quickly become a rat’s nest of cables (and is only going to get worse). Splitting switches using VLANs is good, but having to run multiple cables from other switches to ports which are members of different VLANs seems messy. Undoubtedly, if you had to divide the basement switch 4 ways between tenants who also had space on higher floors you’d use 4 ports on the basement switch just to terminate “feeder” cables from upstairs VLANs.

It should now be clear that some type of generalized method of moving traffic from multiple VLANs between switches on a single cable is needed. Just adding more cables between switches to support connections between different VLANs isn’t a scalable strategy. Eventually, with enough VLANs, you’ll be eating up all the ports on your switches with these inter-VLAN / inter-switch connections. What’s needed is a way to carry the packets from multiple VLANs along a single connection– a “trunk” connection between switches.

Up to this point, all the switch ports we’ve talked about are called “access” ports. That is, these ports are dedicated to accessing a single VLAN. The devices plugged into these ports have no special configuration themselves. These devices don’t “know” that any VLANs are present. Frames the client devices send are delivered to the switch which then takes care of making sure that the frame is only sent to ports assigned as members of the VLAN assigned to the port where the frame entered the switch. If a frame enters the switch on a port assigned as a member of VLAN 12 then the switch will only send that frame out ports that are members of VLAN 12. The switch “knows” the VLAN number assigned to a port from which it receives a frame and somehow knows to only deliver this frame out ports of the same VLAN.

If there were some way for a switch to share the VLAN number associated with a given frame to other switches then the other switch could properly handle delivering that frame only to the appropriate destination ports. This is what the 802.1Q VLAN tagging protocol does. (It’s worth noting that, prior to 802.1Q, some vendors made up their own standards for VLAN tagging and inter-switch trunking. For the most part these pre-standard methods have all been supplanted by 802.1Q.)

When you have two VLAN-aware switches connected to each other and you want those switches to deliver frames between each other to the proper VLAN you connect those switches using “trunk” ports. This involves changing the configuration of a port on each switch from “access” mode to “trunk” mode (in a very basic configuration).

When a port is configured in trunk mode each frame that the switch sends out that port will have a “VLAN tag” included in the frame. This “VLAN tag” wasn’t part of the original frame that the client sent. Rather, this tag is added by the sending switch prior to sending the frame out the trunk port. This tag denotes the VLAN number associated with the port from which the frame originated.

The receiving switch can look at the tag to determine which VLAN the frame originated from and, based on that information, forward the frame out only ports that are assigned to the originating VLAN. Because the devices connected to “access” ports aren’t aware that VLANs are being used the “tag” information must be stripped from the frame before it’s sent out a port configured in access mode. This stripping of the tag information causes the entire VLAN trunking process to be hidden from client devices since the frame they receive will not bear any VLAN tag information.

Before you configure VLANs in real life I’d recommend configuring a port for trunk mode on a test switch and monitoring the traffic being sent out that port using a sniffer (like Wireshark). You can create some sample traffic from another computer, plugged into an access port, and see that the frames leaving the trunk port will, in fact, be larger than the frames being send by your test computer. You’ll see the VLAN tag information in the frames in Wireshark. I find that it’s worth actually seeing what happens in a sniffer. Reading up on the 802.1Q tagging standard is also a decent thing to do at this point (especially since I’m not talking about things like “native VLANs” or double-tagging).

VLAN Configuration Nightmares and the Solution

As you rent more and more space in your building the number of VLANs grows. Each time you add a new VLAN you find that you have to logon to increasingly more Ethernet switches and add that VLAN to the list. Wouldn’t it be great if there were some method by which you could add that VLAN to a single configuration manifest and have it automatically populate the VLAN configuration of each switch?

Protocols like Cisco’s proprietary “VLAN Trunking Protocol” (VTP) or the standards-based “Multiple VLAN Registration Protocol” (MVRP– previously spelled GVRP) fulfill this function. In a network using these protocols a single VLAN creation or deletion entry results in protocol messages being sent to all switches in the network. That protocol message communicates the change in VLAN configuration to the rest of the switches which, in turn, modify their VLAN configurations. VTP and MVRP aren’t concerned with which specific ports are configured as access ports for specific VLANs, but rather are useful in communicating the creation or deletion of VLANs to all the switches.

When you’ve gotten comfortable with VLANs you’ll probably want to go back and read about “VLAN pruning”, which is associated with protocols like VTP and MVRP. For now it’s nothing to be tremendously concerned with. (The VTP article on Wikipedia has a nice diagram that explains VLAN pruning and the benefits therewith.)

When Do You Use VLANs In Real Life?

Before we go much further it’s important to think about real life rather than contrived examples. In lieu of duplicating the text of another answer here I’ll refer you to my answer re: when to create VLANs. It’s not necessarily “beginner-level”, but it’s worth taking a look at now since I’m going to make reference to it briefly before moving back to a contrived example.

For the “tl;dr” crowd (who surely have all stopped reading at this point, anyway), the gist of that link above is: Create VLANs to make broadcast domains smaller or when you want to segregate traffic for some particular reason (security, policy, etc). There aren’t really any other good reasons to use VLANs.

In our example we’re using VLANs to limit broadcast domains (to keep protocols like DHCP working right) and, secondarily, because we want isolation between the various tenants’ networks.

An Aside re: IP Subnets and VLANs

Generally speaking there is a typically a one-to-one relationship between VLANs and IP subnets as a matter of convenience, to facilitate isolation, and because of how the ARP protocol works.

As we saw at the beginning of this answer two different IP subnets can be used on the same physical Ethernet without issue. If you’re using VLANs to shrink broadcast domains you won’t want to share the same VLAN with two different IP subnets since you’ll be combining their ARP and other broadcast traffic.

If you’re using VLANs to segregate traffic for security or policy reasons then you also probably won’t want to combine multiple subnets in the same VLAN since you’ll be defeating the purpose of isolation.

IP uses a broadcast-based protocol, Address Resolution Protocol (ARP), to map IP addresses onto physical (Ethernet MAC) addresses. Since ARP is broadcast based, assigning different parts of the same IP subnet to different VLANs would be problematic because hosts in one VLAN wouldn’t be able to receive ARP replies from hosts in the other VLAN, since broadcasts aren’t forwarded between VLANs. You could solve this “problem” by using proxy-ARP but, ultimately, unless you have a really good reason to need to split an IP subnet across multiple VLANs it’s better not to do so.

One Last Aside: VLANs and Security

Finally, it’s worth noting that VLANs aren’t a great security device. Many Ethernet switches have bugs that permit frames originating from one VLAN to be sent out ports assigned to another VLAN. Ethernet switch manufacturers have worked hard to fix these bugs, but it’s doubtful that there will ever be a completely bug free implementation.

In the case of our contrived example the floor 2 employee who is moments away from providing free systems administration “services” to another tenant might be stopped from doing so by isolating his traffic into a VLAN. He might also figure out how to exploit bugs in the switch firmware, though, to allow his traffic to “leak” out onto another tenant’s VLAN as well.

Metro Ethernet providers are relying, increasingly, on VLAN tagging functionality and the isolation that switches provide. It’s not fair to say that there’s no security offered by using VLANs. It is fair to say, though, that in situations with untrusted Internet connections or DMZ networks it’s probably better to use physically separate switches to carry this “touchy” traffic rather than VLANs on switches that also carry your trusted “behind the firewall” traffic.

Bringing Layer 3 into the Picture

So far everything this answer has talked about relates to layer 2– Ethernet frames. What happens if we start bringing layer 3 into this?

Let’s go back to the contrived building example. You’ve embraced VLANs opted to configure each tenant’s ports as members of separate VLANs. You’ve configured trunk ports such that each floor’s switch can exchange frames tagged with the originating VLAN number to the switches on the floor above and below. One tenant can have computers spread across multiple floors but, because of your adept VLAN configuring skills, these physically distributed computers can all appear to be part of the same physical LAN.

You’re so full of your IT accomplishments that you decide to start offering Internet connectivity to your tenants. You buy a fat Internet pipe and a router. You float the idea to all your tenants and two of them immediately buy-in. Luckily for you your router has three Ethernet ports. You connect one port to your fat Internet pipe, another port to a switch port assigned for access to the first tenant’s VLAN, and the other to a port assigned for access to the second tenant’s VLAN. You configure your router’s ports with IP addresses in each tenant’s network and the tenants start accessing the Internet through your service! Revenue increases and you’re happy.

Soon, though, another tenant decides to get onto your Internet offering. You’re out of ports on your router, though. What to do?

Fortunately you bought a router that supports configuring “virtual sub-interfaces” on its Ethernet ports. In short this functionality allows the router to receive and interpret frames tagged with originating VLAN numbers, and to have virtual (that is, non-physical) interfaces configured with IP addresses appropriate for each VLAN it will communicate with. In effect this permits you to “multiplex” a single Ethernet port on the router such that it appears to function as multiple physical Ethernet ports.

You attach your router to a trunk port on one of your switches and configure virtual sub-interfaces corresponding to each tenant’s IP addressing scheme. Each virtual sub-interface is configured with the VLAN number assigned to each Customer. When a frame leaves the trunk port on the switch, bound for the router, it will carry a tag with the originating VLAN number (since it’s a trunk port). The router will interpret this tag and treat the packet as though it arrived on a dedicated physical interface corresponding to that VLAN. Likewise, when the router sends a frame to the switch in response to a request it will add a VLAN tag to the frame such that the switch knows to which VLAN the response frame should be delivered. In effect, you’ve configured the router to “appear” as a physical device in multiple VLANs while only using a single physical connection between the switch and the router.

Routers on Sticks and Layer 3 Switches

Using virtual sub-interfaces you’ve been able to sell Internet connectivity to all your tenants without having to buy a router that has 25+ Ethernet interfaces. You’re fairly happy with your IT accomplishments so you respond positively when two of your tenants come to you with a new request.

These tenants have opted to “partner” on a project and they want to allow access from client computers in one tenant’s office (one given VLAN) to a server computer in the other tenant’s office (another VLAN). Since they’re both Customers of your Internet service it’s a fairly simple change of an ACL in your core Internet router (on which there is a virtual sub-interface configured for each of these tenant’s VLANs) to allow traffic to flow between their VLANs as well as to the Internet from their VLANs. You make the change and send the tenants on their way.

The next day you receive complaints from both tenants that access between the client computers in one office to the server in the second office is very slow. The server and client computers both have gigabit Ethernet connections to your switches but the files only transfer at around 45Mbps which, coincidentally, is roughly half of the speed with which your core router connects to its switch. Clearly the traffic flowing from the source VLAN to the router and back out from the router to the destination VLAN is being bottlenecked by the router’s connection to the switch.

What you’ve done with your core router, allowing it to route traffic between VLANs, is commonly known as “router on a stick” (an arguably stupidly whimsical euphemism). This strategy can work well, but traffic can only flow between the VLANs up to the capacity of the router’s connection to the switch. If, somehow, the router could be conjoined with the “guts” of the Ethernet switch itself it could route traffic even faster (since the Ethernet switch itself, per the manufacturer’s spec sheet, is capable of switching over 2Gbps of traffic).

A “layer 3 switch” is an Ethernet switch that, logically speaking, contains a router buried inside itself. I find it tremendously helpful to think of a layer 3 switch as having a tiny and fast router hiding inside the switch. Further, I would advise you to think about the routing functionality as a distinctly separate function from the Ethernet switching function that the layer 3 switch provides. A layer 3 switch is, for all intents and purposes, two distinct devices wrapped up in a single chassis.

The embedded router in a layer 3 switch is connected to the switch’s internal switching fabric at a speed that, typically, allows for routing of packets between VLANs at or near wire-speed. Analogously to the virtual sub-interfaces you configured on your “router on a stick” this embedded router inside the layer 3 switch can be configured with virtual interfaces that “appear” to be “access” connections into each VLAN. Rather than being called virtual sub-interfaces these logical connections from the VLANs into the embedded router inside a layer 3 switch are called Switch Virtual Interfaces (SVIs). In effect, the embedded router inside a layer 3 switch has some quantity of “virtual ports” that can be “plugged in” to any of the VLANs on the switch.

The embedded router performs the same way as a physical router except that it typically doesn’t have all of the same dynamic routing protocol or access-control list (ACL) features as a physical router (unless you’ve bought a really nice layer 3 switch). The embedded router has the advantage, however, of being very fast and not having a bottleneck associated with a physical switch port that it’s plugged into.

In the case of our example here with the “partnering” tenants you might opt to obtain a layer 3 switch, plug it into trunk ports such that traffic from both Customers VLANs reaches it, then configure SVIs with IP addresses and VLAN memberships such that it “appears” in both Customers VLANs. Once you’ve done that it’s just a matter of tweaking the routing table on your core router and the embedded router in the layer 3 switch such that traffic flowing between the tenants’ VLANs is routed by the embedded router inside the layer 3 switch versus the “router on a stick”.

Using a layer 3 switch doesn’t mean that there still won’t be bottlenecks associated with the bandwidth of the trunk ports that interconnect your switches. This is an orthogonal concern to those that VLANs address, though. VLANs have nothing to do with bandwidth problems. Typically bandwidth problems are solved by either obtaining higher-speed inter-switch connections or using link-aggregation protocols to “bond” several lower-speed connections together into a virtual higher-speed connection. Unless all the devices creating frames to be routed by the embedded router inside the later 3 switch are, themselves, plugged into ports directly on the layer 3 switch you still need to worry about the bandwidth of the trunks between the switches. A layer 3 switch isn’t a panacea, but it’s typically faster than a “router on a stick”.

Dynamic VLANs

Lastly, there is a function in some switches to provide dynamic VLAN membership. Rather than assigning a given port to be an access port for a given VLAN the port’s configuration (access or trunk, and for which VLANs) can be altered dynamically when a device is connected. Dynamic VLANs are a more advanced topic but knowing that the functionality exists can be helpful.

The functionality varies between vendors but typically you can configure dynamic VLAN membership based on the MAC address of the connected device, 802.1X authentication status of the device, proprietary and standards-based protocols (CDP and LLDP, for example, to allow IP phones to “discover” the VLAN number for voice traffic), IP subnet assigned to the client device, or Ethernet protocol type.

 

By Evan Anderson

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TEDx Nairobi 2014: A WasTED World?! Dec. 6 2014 @ Catholic University of Eastern Africa

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This event will be mind-blowing. If you miss out, there is always next year.

Nairobi Now :: arts, culture and events

Save the World

Once every year, the TED experience comes to our city at the TEDxNairobi event. This year’s TEDxNairobi will be held on December 6th at the Catholic University of East Africa (CUEA) in Karen. The event will run from 9:30 am to 6:00 pm. This is a registration-only event strictly limited to 500 participants, so please register today.

TED stands for Technology, Entertainment, Design – three areas that are collectively shaping the cutting edge of our horizons. The fascinating and passionate TEDTalks have reached over a billion views through ted.com, enlightening audiences worldwide with their powerful ideas. TEDxNairobi operates under a license from TED and is a self-organized event that creates a platform for international and local speakers to bring the TED experience to Nairobi.

In this our fifth year, we have decided to provoke more complex conversations with some brilliant minds by using the theme of “A WasTED World?!” Because…

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What are the most difficult things people have to learn in their 20s?

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Answer by Rich Tatum:

Here are some things I really, really wish I knew when I was twenty.

  • Love hurts, but not as much as not loving.
  • The friendships you nurture will have a greater effect on your life than where you work or what you earn.
  • You are not your job. You are not your bankroll. You are not the sum of your possessions.
  • The company does not love you. It has no heart. You are replaceable. Keep your parachute handy.
  • Few decisions will ever shape your future life more than who you choose to marry. To marry well, you must choose well.
  • Love is a commitment.
  • Your passions will grow out of your values. Make early, wise choices to value what (and who) is good, trustworthy, and praiseworthy.
  • Integrity preserved is honor won.
  • Rejoice in your health. It fades fast.
  • Find a passion. Pick a hobby, own it: photography, juggling—whatever. Get your 10K hours of perfect practice in early and change your life.
  • Don’t bother comparing yourself to others—this only leads to heartbreak, anger, and disappointment.
  • Most disappointments arise from unmet expectations. Set realistic expectations for yourself, based on your strengths, then strive to exceed them.
  • Don’t drive others to meet expectations they’ve committed to — lead, inspire, and help them do it.
  • Don’t set expectations for others when they have not or cannot commit to them.
  • Expectations you never communicate and negotiate will rarely be met—except by accident.
  • Don’t complain. Either change your situation, learn to cope, or change perspective.
  • Don’t worry about getting a big salary in your youth: first learn to execute tasks with skill, excellence, and grace.
  • Little stuff matters—even in lowly jobs. The boss notices—and even if not, your peers and colleagues will.
  • Ultimately, privacy is a myth: God sees everything. The cloud records everything. NSA files everything. So, live transparently and don’t waste useless energy hiding failures.
  • Don’t look down on others because they don’t have what you didn’t earn: your intellect, your beauty, and your culture of birth are undeserved gifts. Stay humble.
  • Failure is an opportunity: no great man or woman ever achieved significance without great failures. Fail forward.
  • Never withhold an apology when it’s merited. Deliver it quickly, sincerely, and personally—before resentment festers.
  • You don’t need to nurture old guilt when you’re forgiven. But remembering the shame can help you avoid repeats.
  • Mere belief in anything signifies little more than assent: trust and behavior reveal where true convictions lie.
  • The main thing you need to do quickly is to stop doing things quickly. Trade hurry for calm, confidence, and precision.
  • Everybody needs an editor. Everybody. Especially editors.
  • Get your work done first so you can play without guilt. Even better, make work play and the fun never ends!
  • If you want to develop your passion and gift, stop worrying about the things you do poorly. Go with your strengths!
  • Avoid fights. Seriously. Avoid them like a plague: nobody wins in a fight, even if you walk away unscathed. But when a fight picks you, leave everything on the mat and give it your all. Hold nothing back.
  • If you’re bored, you’re doing it wrong.
  • The skills that will help your career most are the abilities to assimilate, communicate, and persuade. Keep learning.
  • Nothing in this life—no pain, no agony, no failure—compares to the eternal joy of Heaven. Live in light of eternity.
  • Protect your joy. Nothing is easier to lose by over-thinking, overanalyzing, and second-guessing. On the other hand, always consider the long-term consequences of your choices: stupid decisions made in the moment can rob you of years of joy and happiness.
  • Your purpose in life determines how you frame events. You can maintain your joy in the most dire circumstances if you find meaning for your life. Dig deep.
  • It truly matters what you think about. Think well by reading good books, building good, loving relationships, having good conversation, and imitating great people.

I’m still learning — in fact I haven’t fully appreciated most of the list I made, myself. And I’m still adding to it. But I’m getting better.

Rich
http://twitter.com/RichTatum

What are the most difficult things people have to learn in their 20s?

Office Remote App-Turn Your Phone To A Smart Remote

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Best App for Presentation… technology

mceworld

Office Remote turns your phone into a smart remote that interacts with Microsoft Office on your PC. The app lets you control Word, Excel, and PowerPoint from across the room, so you can walk around freely during presentations. With Office Remote, you can start your PowerPoint presentation, advance the slides, see your speaker notes, and control an on-screen laser pointer with a touch of your finger — all from your phone. You can also navigate between Excel worksheets and graphs, and control data slicers from the palm of your hand. And you can scroll through a Word document or quickly jump to specific sections or comments.

Features

PowerPoint:
– Jump to the next, previous, and last slide
– View slide thumbnails and jump to a slide
– View speaker notes on phone
– View presentation timer and slide numbers
– Laser pointer using touch on your phone
Excel:
– Change…

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How to Install Drivers for Canon Printers PIXMA IP Series on Ubuntu 12.04 – 14.04

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Canon is the largest printer manufacturer, but it does not have drivers for every printer model, running on Linux.

I will show you how to install the Ubuntu drivers for Canon IP Series Printers, on Ubuntu 14.04 Trusty Tahr, Ubuntu 13.10 Saucy Salamander, Ubuntu 13.04 Raring Ringtail, Ubuntu 12.10 Quantal Quetzal and Ubuntu 12.04 Precise Pangolin

The installation instructions are for the following Canon printers:

  • Canon iP100 Ubuntu Driver –  cnijfilter-ip100series
  • Canon iP1800 Ubuntu Driver – cnijfilter-ip1800series
  • Canon iP1000 Ubuntu Driver – cnijfilter-pixmaip1000series
  • Canon iP1500 Ubuntu Driver – cnijfilter-pixmaip1500series
  • Canon iP1900 Ubuntu Driver – cnijfilter-ip1900series
  • Canon iP 2200 Ubuntu Driver – cnijfilter-ip2200series
  • Canon iP2500 Ubuntu Driver – cnijfilter-ip2500series
  • Canon iP2600 Ubuntu Driver – cnijfilter-ip2600series
  • Canon iP2700 Ubuntu Driver – cnijfilter-ip2700series
  • Canon iP3300 Ubuntu Driver – cnijfilter-ip3300series
  • Canon iP3500 Ubuntu Driver – cnijfilter-ip3500series
  • Canon iP3600 Ubuntu Driver – cnijfilter-ip3600series
  • Canon iP4200 Ubuntu Driver – cnijfilter-ip4200series
  • Canon iP4500 Ubuntu Driver – cnijfilter-ip4500series
  • Canon iP4700 Ubuntu Driver – cnijfilter-ip4700series
  • Canon iP4800 Ubuntu Driver – cnijfilter-ip4800series
  • Canon iP5200 Ubuntu Driver – cnijfilter-ip5200series
  • Canon iP6600 Ubuntu Driver – cnijfilter-ip6600series
  • Canon iP7500 Ubuntu Driver – cnijfilter-ip7500series

Add the repository and update the system:

$ sudo add-apt-repository ppa:michael-gruz/canon-trunk
$ sudo apt-get update

For Ubuntu 14.04 Trusty Tahr ONLY, you need the libtiff4 library which is not available via the default repositories, but we can download it from the Debian Sid sources.

Download and install the libtiff4 library, for either 32 bit and 64 bit systems:

How to install the libtiff4 library on 32 bit Ubuntu 14.04 system:

$ wget http://cz.archive.ubuntu.com/ubuntu/pool/universe/t/tiff3/libtiff4_3.9.7-2ubuntu1_i386.deb
$ sudo dpkg -i libtiff4_3.9.7-2ubuntu1_i386.deb
$ sudo apt-get install -f

How to install the libtiff4 library on 64 bit Ubuntu 14.04 system:

$ wget http://cz.archive.ubuntu.com/ubuntu/pool/universe/t/tiff3/libtiff4_3.9.7-2ubuntu1_amd64.deb
$ sudo dpkg -i libtiff4_3.9.7-2ubuntu1_amd64.deb
$ sudo apt-get install -f

And install the drivers for your printer:

Canon iP100 Ubuntu Drivers:

$ sudo apt-get install cnijfilter-ip100series

Canon iP1800, iP1880, iP1890 Ubuntu Drivers:

$ sudo apt-get install cnijfilter-ip1800series

Canon iP1000 Ubuntu Drivers:

$ sudo apt-get install cnijfilter-pixmaip1000series

Canon iP1500 Ubuntu Drivers:

$ sudo apt-get install cnijfilter-pixmaip1500series

Canon iP1900 Ubuntu Drivers:

$ sudo apt-get install cnijfilter-ip1900series

Canon iP2200 Ubuntu Drivers:

$ sudo apt-get install cnijfilter-ip2200series

Canon iP2500 Ubuntu Drivers:

$ sudo apt-get install cnijfilter-ip2500series

Canon iP2600 Ubuntu Drivers:

$ sudo apt-get install cnijfilter-ip2600series

Canon iP2700 Ubuntu Drivers:

$ sudo apt-get install cnijfilter-ip2700series

Canon iP3300 Ubuntu Drivers:

$ sudo apt-get install cnijfilter-ip3300series

Canon iP3500 Ubuntu Drivers:

$ sudo apt-get install cnijfilter-ip3500series

Canon iP3600 Ubuntu Drivers:

$ sudo apt-get install cnijfilter-ip3600series

Canon iP4200 Ubuntu Drivers:

$ sudo apt-get install cnijfilter-ip4200series

Canon iP4500 Ubuntu Drivers:

$ sudo apt-get install cnijfilter-ip4500series

Canon iP4700 Ubuntu Drivers:

$ sudo apt-get install cnijfilter-ip4700series

Canon iP4800 Ubuntu Drivers:

$ sudo apt-get install cnijfilter-ip4800series

Canon iP5200 Ubuntu Drivers:

$ sudo apt-get install cnijfilter-ip5200series

Canon iP6600D Ubuntu Drivers:

$ sudo apt-get install cnijfilter-ip6600dseries

Canon iP7500 Ubuntu Drivers:

$ sudo apt-get install cnijfilter-ip7500series

Now plug in your Printer and enjoy!
Cheers!
Lima Kilo

Website Hosting also Free Choices

Standard
Nowadays I see a lot of folks talking about web hosting. Most of the time, people don’t know that different websites require different solutions and therefore different hosts. They also don’t know the difference between a host and a domain name, and that there are services for each one of those problems. Here I will try to tackle this a little bit and give you a few suggestions.Thus, by the end of this article, you should be able to answer the following questions on your own:

  • What is Web Hosting and Domain Naming?
  • Is a Domain Name absolutely necessary?
  • What are the main difference between Static Web pages and Dynamic We pages?
  • Is my website static or dynamic?
  • What free solution should I pick to host my website?

Definitions

For the purpose of this article, we will use the following definitions of web hosting and domain naming as follows:

Web Hosting

Consists in hosting and keeping files and data for websites, in machines called servers, that give away part of they available disk space to maintain the data. Web servers also provide internet access, which can be payed separately.

Domain Name

A name owned by a person or a company, made of a string composed by letters, number and special characters, used as an internet address that identifies the location of specific webpages.

So, now that we have these two aspects defined let’s see how they play together. A Web Hosting service, will give you a machine with a connection to the internet, where you can put your website’s data. Because the machine is connected to the internet, everyone can access it’s contents by using the machine’s IP address. However, IP numbers are long sequences, and are also very hard for people to memorize. To fix this problem, the Domain Name System was created. Shortly put, this system maps IP numbers, to website names that you can memorize.

Your needs

So, now that you know that Web Host service will give you a computer (server) to store data, and a Domain Name service will map the server’s IP address into a name that people can memorize, it is time to understand what your web site needs.

To know what your website needs, you must know the type of your website. Websites are made of Web Pages, and there are two main types of these:

  1. Static Web page: Also called flat page/stationary page, this is usually a web page that never changes, and that presents the same content in the same way to all users no matter what. Static Web pages are usually made using only HTML and CSS, and are the easiest to create because they don’t require databases, nor advanced programming skills. Some Static Web Pages can also use javascript and jquery to present content, but there is never the need to store data from the user in any case. To deploy a static Web page, all you need to do is to place your files in a server connected to the internet.
  2. Dynamic Web Page: A dynamic web page is generated in real-time. These pages usually include web scripting code and require access to databases in order to keep and manage information from users or programs. These Web pages usually use frameworks, and languages like Ruby, PHP, Python, Java, Javascript and so on to make the communication with the server’s local database easier.

With this information we can then make the following statement: If a Website contains one or more Dynamic Web pages, it is a dynamic website, otherwise it is a Static Website.

Overall, Static Websites are easier to create, and are ideal for beginners. Dynamic websites, require more knowledge and are harder to create, but they are a lot easier to maintain then static websites due to all the automation they have.
The list of advantages and disadvantages between static and dynamic websites goes longer, but these are the basics you need to know.

Your choices

So, now that you probably know the type of website you are building, it’s time to evaluate the market that exists. The important thing here is the type of Web hosting service that you will need. Some web hosts only allow for static web sites, while others also allow for dynamic.
Domain Name services are independent of your web host, however, sometimes the web host company also provides an integrated web naming service that you can use.

Free Web Hosting for Static Websites:

Free Web Hosting for Dynamic Websites:

All these web hosts will make your webpage available online for everyone for free, however they will create very long and horrible links for your websites. This is where Domain Naming comes in.

Free Domain Naming services:

Using Custom Domain with Google Drive:

Using a Custom Domain with Dropbox:

An alternative to choosing a domain and a name for your website is also URL shortening:

Free URL shorteners services:

For more information about this section, please visit the Sources Section.

Summary

By now you should be able to answer the formulated questions presented in the introduction. Web hosts provide servers that can hold your data and are connected to the internet. Domain Names are pretty much “masks” that map IP addresses and other horrible long names into string that people can actually memorize. URL shorteners can therefore be seen as a sort of Domain Naming service, provided of course that you can actually memorize the URL they give you.
Last but not least, the more complex your website is, the more complete the service you rent must be. Dynamic websites many times require complex online platforms such as Heroku or Google Apps to be deployed, and there are many others out there depending on the language set you use.

Sources:

Definitions:

Web hosting: http://en.wikipedia.org/wiki/Web_hosting_service
Web hosting: http://www.w3schools.com/hosting/default.asp
Domain Name: http://www.techterms.com/definition/domain_name
Domain Name: http://dictionary.reference.com/browse/domain+name
IP address: http://www.techterms.com/definition/ipaddress
Domain Name System: http://en.wikipedia.org/wiki/Domain_Name_System

Your Needs:

Static Web Page: http://www.techterms.com/definition/staticwebsite
Static Web Page: http://en.wikipedia.org/wiki/Static_web_page
Dynamic Web Page: http://www.techterms.com/definition/dynamicwebsite
Dynamic Web Page: http://en.wikipedia.org/wiki/Dynamic_web_page
Static website’s advantages, disadvantages and examples: http://nellen.co.za/static-websites
Dynamic vs Static Websites, what’s the difference?: http://www.edinteractive.co.uk/article/?id=4

Your Choices:

Dropbox free web Hosting: http://www.groovypost.com/howto/host-simple-website-dropbox-free-hosting/
Best free Domain Naming services: http://www.prchecker.info/web-hosting/best-free-domain-name-services/
How to Host a Website on Google Drive : http://www.codeitpretty.com/2013/03/how-to-host-website-on-google-drive.html
Extra URL shortners: http://www.webdevelopersnotes.com/resources/shorten-url.php

Special Thanks

 

Hope that helps.

Lima Kilo

Finding a computer’s model using command prompt & terminal

Standard

May be you want to find out the drivers for your PC and you need to be specific, you have to have the model of your PC. It’s fairly simple.

A. On Windows Command Prompt:

wmic csproduct get name

On my machine that returns two lines, one saying Name and another with my machine’s model name:

Dell Inspiron 15 N5040

Now that’s cool!!

B. For Linux Terminal:

sudo dmidecode | grep -A3 '^System Information'

1

This is what you get:

2

Hope it helped.

Cheers!

Lima Kilo