Labels

Showing posts with label Tips. Show all posts
Showing posts with label Tips. Show all posts

Sunday, May 16, 2021

Tips #11 - Shorthand notation for network diagrams

The following are some example rules for diagram shorthand notation.  This was developed to be able to not only indicate where the connections are, but to identify the ports on each end.  Makes it easy to put a wiring list together.

  • General Format: {port_from}[What_flow_contains]{port_to}
  • Port designation: {device-port}
    • {ONT} for Verizon ONT
    • {SW1-5} for Switch#1, port 5
    • {RT3-2} for Router#3, port 2
    • {RT3-W} for Router#3, wan port
    • {RPi05-D1} for Raspberry Pi #5, dongle on usb port 1
    • {RPi05-E} for Raspberry Pi #5, ethernet port
    • {PP1-15} for patch panel #1, port 15
  • Flow designation: [non_tagged_vlan/Ttrunk_vlan_list]
    • [32] for non-tagged vlan 32
    • [T4,6,8] for tagged vlans 4, 6, and 8
    • [12/T14,70] for non-tagged vlan 12 with tagged vlans 14 and 70
    • [Trunk] for generic <defined elsewhere> trunk with tagged vlans; shorthand

Sunday, March 21, 2021

Tips #10 - Network Setup for Raspberry Pi Static Experiments

After some time working with Raspberry Pis (RPi) I have been able to figure out the kind of network setup that makes sense when you develop over a period of time.  Here are some particulars of what I have found:
  • Use of a Managed Switch with a trunk line to all of the vlans in the house saves a lot of running around.
  • Use of Tasmota controlled extension cables can give you control of power to the RPis in case there are moments when you only want to concentrate on specific RPis for an experiment
  • The managed switch on the desk where you wire up experiments gives you extra network connections when needed.
  • The key is to be able to work on just what you want without having other thins on when you don’t need them to be on.

Tips #9 - The Sacrificial Port and Admin vlans

One thing I have discovered in my attempt to be secure is the use of Admin vlans.  An Admin vlan is a vlan that you use to limit changes to your network.  This is for internal network infrastructure protection. There are a couple of important points about this:
  • Each router, Managed Switch, and Type 1 hypervisor that you have in your network is configured so that changes can only be made from the Admin vlan.
  • All ACs/Rules setup in the network enforce the Admin vlan to be separate from all others and enforces the items in this list.
  • You set up connections throughout the network so that you have to be physically connected to an Admin vlan port to make changes to any infrastructure elements in the network.
  • We have a port on each device dedicated to the Admin vlan, but the Admin vlan is allowed to traverse between devices only on Trunk lines and those lines are physically protected as much as possible.
  • All connections on the Admin vlan devices have to be encrypted; this is a zero trust approach.
  • Encrypted Certs are controlled by a local Certificate Authority (CA) that is usually offline.
  • The Admin vlan port is called the Sacrificial Port because that port is only used for the purpose of getting to the Admin vlan.
  • The sacrificial port is protected with an 802.1x/Radius connection by MAC address; if you aren’t supposed to be there you shouldn’t be allowed to get in.
  • The sacrificial Port is also there to make sure you can still control infrastructure devices if part of the network becomes unresponsive.
  • The Sacrificial Port is also protected by a keyed Ethernet dust plug (suggest the color Red); key is necessary to take the plug out of the device.

Friday, February 19, 2021

Tips #8 - Using a Router as an Access Point with Multiple SSIDs

In the course of helping someone out on Reddit about their setup, it occurred to me that there have been multiple instances of people asking about using an old router as an access point.  It also helps if you consider the advice peppered with multiple VLANs and multiple SSIDs.  Lets assume you have a Wi-Fi router and want to use another router as an access point (lets call it AP).  Further, lets assume that you have two VLANs you wish to use.  Here are some things to consider (not in any particular order):

  • You probably will want to do a Wi-Fi survey to see where your neighbors are parked on the Wi-Fi spectrum and figure out from there how you want to minimize interference - I recommend Acrylic Wi-Fi as the tool to use, there is a free version.  There are also some tools under Kali Linux as well.
  • If you have a mobile device, you will generally want to seamlessly switch between Wi-Fi sources.  To do this, you are going to want to have the Wi-Fi router and AP on different Wi-Fi channels.  So, as a general rule walking around your house will cause your cell phone to connect to the Wi-Fi source with the strongest signal. If on the other hand the one SSID is on the same Wi-Fi channel on both devices you could wind up with them interfering with each other.
  • We will assume you have VLANs that you are using to separate the networks.
  • I make it a point to have different SSIDs based on the vlan it is connected to, so if you have 2 VLANs, you should use 2 SSIDs (different names). 
  • Always make sure that the SSIDs have the same passphrase across the devices, but use two different passphrases for two different SSIDs. Then the SSIDs will be cryptographically separate from each other.
  • Most smart home devices will use the 2.4GHz spectrum, rarely will you see it connect to 5.4GHz, so you could in effect only need the 2.4GHz spectrum for the smart devices and that may influence your choice for how you set up each SSID.
  • If you have smart TVs, I would try to use Ethernet as much as is possible to connect them; video chews up a lot of Wi-Fi bandwidth.
  • Don't setup the AP in bridge mode; that implies that you are going through the WAN port. There is no need to do that if you are using it as an access point. Connect the cable from a port on LAN side of the router to one of the ports on the Linksys LAN side. This cable should be designated as a trunk line, i.e. it will be carrying multiple VLANs.  By doing it that way, you will keep the one SSID to one vlan mantra unaltered.  Setup the VLANs accordingly.
  • In the AP vlan setup do not setup a DHCP server, but use a DHCP relay mode instead, and point the relay address to the router vlan IP address. That way a connection to the AP will use the router to get it's IP address (which also means it will get it's DNS info from the same source).

This is simple but effective and I have used this approach many times to success.

Friday, October 2, 2020

Tips #7 - My Network Philosophy in So Many Words

When considering how to think about, design, and develop a home network you must consider your specific situation.  If I were to pick one topic I would have to stress the word CHANGE.  Change will happen to your network over time and you must be able to react and plan for it.  Networks are never static over time.  Here are some items to consider:

  1. Are you going to stay put for very long?
    • Renters know this, you don't just punch a hole in the wall to do something; you will end up having to repair it before you leave
    • The answer to this question might mean the difference between an all wifi or a partial wifi solution
  2. What are you planning on doing with your network?
    • You may have simple plans for what you are doing now, but what about the future uses?
    • It's not always about gaming
    • Consider things like setting up for IOT, cameras, and media in the future
    • Write up a list of the order of importance for things you will use the network for
  3. Cables will stay, devices will always be subject to moving
    • If you have spent the time putting a cable into a wall or overhead, you will really not want to move it again
    • I have moved my main router to 5 different locations in my house over the years - will you have to do the same
    • Consider the fact that equipment may fail and have to be replaced
    • You may, over time, have different ISPs that you deal with - I have dealt with 3 different ISPs over the years, each one had a different way of presenting their services to my house (dial up, cable, fiber optic)
  4. Do you really want to drill that hole?
    • Once you drill a hole, you are stuck with it
    • If you ever move you will have to repair it
    • Placement of a hole is important, can it be hidden - not everyone wants to see a cable sticking out of a wall, especially spouses
  5. Always start with the cabling
    • If your neighbors are "jaming" the wifi signal it will be nice to be able to fall back on cabling to supply your network needs
    • Don't forget you have options: Ethernet, Coax Cable, fiber optic in addition to wifi
  6. Patch panels, strategically placed, help in the movement of equipment
    • If you use keystone patch panels with straight through couplers you will always have the ability to use already made cables
    • Couplers allow you to move the positions of the Ethernet cable ends on a single patch panel
    • Patch panels allow you to use small patch cables to make one long connection between patch panels when a direct connection was not available
  7. Consider the judicious use of vlans in the Network to isolate equipment
    • Vlans give you the ability to minimize the number of cables run to different parts of the house; you use a "trunk" line from one managed switch/router to another and keep other ports on the router/managed switch to one specific vlan
    • Vlans give you the ability to isolate different segments of your network for different purposes
    • If the router from your ISP doesn't have vlan capability, you can always put a router behind it that does, or alternatively use your own router for the connection to the ISP
  8. Use the highest bandwidth switches and routers that your budget will allow
    • As bandwidth gets cheaper, and/or the signal from your ISP changes over time you may encounter a situation where it is advantageous to have already installed equipment that can meet the bandwidth increase
    • This means that you should always consider the cabling and what it's bandwidth capability provides; right now Cat5e should be sufficient, but you may want to consider Cat6 and above for growth
  9. Always consider the unthinkable, like failures and how it will affect the network
    • I have had older equipment fail on me when it was most inconvenient; being able to quickly replace the equipment because you thought out the problem beforehand will help
    • I have lost equipment to lightning strikes; never assume that it will not happen to you
    • Put lightning arrestors on Ethernet lines from the outside and on Coax cable connections to equipment
    • If at all possible get a whole house surge protector for those times when a higher than usual voltage spike happens that gets into your house
    • If it is within your budget consider the judicious use of UPS at different spots in your network; sometimes a hard fail of power will cause a failure in hard drives
    • If some piece of equipment fails in the network, how fast can you come back up to a semi normal state, or at least most of your list of network importance from #1 above
  10. Consider security when you are setting up the network
    • It goes without saying that IOT equipment needs to be isolated, due to it's very nature of contacting outside servers; if at all possible, keep the information in your house
    • Never assume that the router on the perimeter will always protect you from intruders; in fact, always assume that someone has already attacked and entered your network and design accordingly


Wednesday, July 1, 2020

Tips #6 - Faking an Admin vlan on the Netgear GS108Ev3 and GS116Ev2

My network at home is distributed and I try to minimize the number of wires going throughout the house.  That becomes a problem if you are single switch dependent.  But with judicious use of vlans throughout the house, I can distribute these through the use of trunk lines.  One thing I am very conscious about is security in the network.  I make judicious use of Admin vlans in order to keep the network framework from being changed by someone who has hacked into my system.

I went out and bought a GS108Ev3 thinking it was a good and cheap alternative to the GS108Tv2.  Boy was I wrong.  My focus on security took a nose dive, or so I thought, when I started incorporating this switch into my network.  It was the same thing for the GS116Ev2 when I added this switch.  If you follow a simple set of rules, you can keep your Admin vlan:


  1. a normal Netgear managed switch like the GS108Tv2 has an Admin vlan capability.  In fact, you can actually put the vlan number into a field in the web interface.  The switch will use this vlan number to accept DHCP IP addresses for the switch.  If you fix the IP address of the switch, you will need to be in the subnet of the Admin vlan for the switch to work.
  2. there is a new class of Netgear switches, like the GS108Ev3 and the GS116Ev2 which are simplified but have much of the capabilities of the GS108Tv2.  One of the capabilities that is missing is the Admin vlan.  There is no field to set it and you are forced to use vlan 1 in some manner to interface to your network.  You do that on a trunk port
  3. On GS108Ev3/GS116Ev2: either use DHCP or set the IP address/Gateway to be within the Admin vlan subnet
  4. On GS108Ev3/GS116Ev2: set vlan 1 to be untagged on the trunk port; set the Admin vlan to be tagged on the trunk port; set the Admin vlan to be the PVID on the trunk port
  5. On GS108Tv2/M4100: set the Admin vlan to be the PVID on the trunk port; set the Admin vlan to be tagged on the trunk port
  6. On GS108Ev3/GS116Ev2: no other ports may have vlan 1 as untagged, except the trunk ports

Not a difficult configuration, but as long as you remember the rules you can get an Admin vlan on these GS108Ev3/GS116Ev2 switches.

Friday, June 26, 2020

Tips #5 - Alignment 101 on a 3D Printer

After I purchased my Hictop Prusa i3 Clone four years ago, I went through a very trying time attempting to discover what things were going wrong with the printer.  It seemed like I got excellent prints, then there was a disaster, something out of kilter, or even an indication that squares weren't square anymore.  The more I fiddled, the more I discovered some unwritten rules of keeping a 3D printer up to date, at least in alignments.  So here are some tips for making better use of time between issues that arise (note that these items are for Reprap style printers, like the Prusa i3, but the principles are the same with most printers):

Assumptions:

  1. Get used to the idea that you will have to re-align the printer every so many prints, even with an auto-leveler
  2. Over time the correction adjusters will come loose because of shaking and general acceleration of parts
  3. The same shaking will cause corners and cams to come loose
  4. Belts do not stay perpetually tight
  5. Mechanical stuff will wear out and will need replacing

Rules:

  1. Make sure the printer is off, it makes it easier to move things around without having to disable the stepper motors.
  2. Start by making sure that all of your 3D printer corners are exactly square.  You may think that you have a 90 degree corner but unless it is measured to be 90 degrees, it is not.  If the corners are not aligned, you will not see a rectangle on prints, you will see a rhomboid, and if it is really bad a trapezoid.
  3. First and foremost after squaring the printer, make sure that all bolts are tightened on the printer
  4. Make sure that all belts are tight and that the cams are on the stepper motors correctly (usually by having the set screw on the flat portion of the spindle); make sure all cam set screws are tight.
  5. Check the movement of the belts as they are moved back and forth.  What you are looking for here is making sure that the belt moves easily without binding, or rubbing on anything; especially important for the X and Y axis belts.
  6. Clamp the printer structure to its surface to prevent shaking that might cause the printer to move from its location.
  7. Now we start aligning stuff.  Start by making sure the printer structure itself is level in the XY plane, use a level - I prefer a magnetic level and sometimes use a circular level.  You would be surprised to find that most surfaces are not level.  Sometimes some wooden shims are needed to get it level on a table or bench surface.
  8. Once the structure is level, level the print bed (moves in the Y axis direction) using the adjustment screws on all four corners.  You need to have it level from corner to corner and diagonally.  I like to start in the middle of the bed checking diagonal level in both diagonals.
  9. Apply blue tape if you use it to the bed.
  10. Next, check the level of the X axis beam on the metal rods that the print head travels on.  If the metal rod is not level you will need to adjust the Z axis couplers on one side or the other to bring it into a level condition.  If the printer had been on you would need to unlock the stepper motors to do this.
  11. Next, check the distance of the print head from the bed by adjusting the Z axis couplers on either side of the bed to bring it up or down as necessary.  I generally find that the width of a separation tool is enough, others like the width of a piece of paper.
  12. Recheck the X axis level after changing the Z axis couplers.
  13. Turn on the printer.
  14. Adjust the auto-leveler so that it just comes on with the present settings.
  15. Attempt an auto home. Recheck the distance of the print head from the bed.  If adjustment is needed, unlock the stepper motors prior to moving the Z axis couplers and readjust auto-leveler as per #11 and #14.  Repeat until the distance of the print head is acceptable.
  16. At this point you are as aligned as you can be mechanically.
  17. To help keep alignment, consider lowering the maximum acceleration level and the xy jerk value; this will also serve to lower the shaking and “walking” that most printers tend to have.
  18. Higher temperatures will add to misalignment due to expansion of metal parts.  So recheck alignment of the bed after a high temperature print.

Friday, June 19, 2020

Tips #4 - vlan expressions for documentation

If you have a network running through your house like I do, and have vlans as part of it, then you probably have some so called "trunk" Ethernet cables.  So how do you explain what vlans are where?  This is what I do:

  • A port on a router or a switch that has an untagged vlan is noted with brackets around the vlan number like [4] for an untagged port with vlan4 present.
  • When designating a "trunk" port on a router or a switch you have tagged vlans and you have a PVID assigned.  I put the PVID first, to know what vlan is used when there is no tagging, a slash, and then a T followed by a list of each of the vlans that are tagged on that port.  So it looks like [6/T4,8,88,123-124,152] for a PVID of vlan6 with tagged vlans: 4, 8, 88, 123, 124, and 152.  I still put brackets around the values to designate that these are vlans I am dealing with.  I use the dashes as a shorthand noting that this includes all of the vlan numbers in between.
  • I generally like to make the "trunk" lines between switches and routers have a standard grouping of vlans.  In that way, a shorthand would be [6/T] where the tagged vlans are common across the entire network.
  • When I use "trunk" lines, I like to reserve a couple of vlans for specific purposes other than normal traffic.  
  • I use vlan850 as a shorthand in a switch to denote that the ports that use vlan850 are all untagged and serve as a short unmanaged switch.  I never allow vlan850 to be included in any "trunk" configurations.
  • I use vlan11, always untagged, as a dead port designation.  What this means is that vlan11 does not get assigned to any "trunk" configuration and serves to simply block a port from being useful when it is not used.
  • I use several vlans, for example 66 through70, as temporary patch vlans.  What this means is that I can attach an untagged port to a switch on one end of the house and an untagged port to a switch on the other end of the house and effectively have a "patch cable" in between the ports.  One caution, normally you cannot assign one end to the same port as a monitor port on a switch, at least I haven't figured out how to yet.



Tips #3 - Documentation on Networks and Vlans

As your home network grows, so does the level of confusion about what was wired up where and when.  In general, you can document what happened through a journal about changes you have made to the network.  But filtering through that journal when you are in the midst of making lots of changes will be very time consuming.  It is better to keep the information in a separate list.  Normally, devices that you have in the network will retain certain Ethernet addresses, but sometimes the wiring will change and the placement of the equipment as well.  There are four specific documents that I use to document different views of the network and provide an easier way of changing the layout as my equipment, equipment placement, wiring, etc. change over time.  In my case, I keep the four documents as notes in my CellPhone under a classification of HomeNetwork.  The four documents are:
  1. Current IPs in the Network
  2. Patch Panels
  3. Cable Connections
  4. Home Vlans
These are described below:

-- Current IPs in the Network
  • The "Current IPs in the Network" and "Home Vlans" rarely if ever change.  However, if I move a piece of equipment in my network, "Patch Panels" and "Cable Connections" will be altered.  If I move a piece of equipment from one vlan to another, by definition the "Current IPs in the Network" will change, along with notations about the connections in the other documents.
  • The "Current IPs in the Network" note should contain all known IPs that you have in your home network.  I have even included IPs from equipment that are connected to multiple vlans.  That way the document is all inclusive.  I also make sure that all IPs that show up in my network are known.  If it isn't on the list then I know someone has attached themselves to my network that I don't know about and I go and hunt down what it is.  Rogue pieces of equipment or IOT equipment that doesn't behave I disconnect.
-- Patch Panels
  • I have already described how I label patch panels here.
  • The "Patch Panels" note documents the infrastructure of the network
  • The "Patch Panels" note is broken down to each patch panel with what is connected by port number on that patch panel.
  • The "Patch Panels" not does not contain any information about what equipment the port connects to, i.e. with a patch cable connection from the device to the patch panel, only documentation of what connections exist.  
  • There is an exception where the patch panel port actually goes directly to a device and is designed to be there consistently.  For instance, I have a PiHole in my network and that is connected behind one of my patch panels.  So for the label on that patch panel, I label the port as "PiHole", e.g. PP#3-7 is labeled PiHole so I know where the port goes to.
  • I use the term "patch to" when describing the use of a patch cable at a specific patch panel.  For instance one of my patch designations at patch panel 3 port 11 is "PP#3-11 - PP#1-10".  I can usually read where the port is going by looking at the actual patch panel.
  • If I have a patch cable going between ports on a given patch panel, my "Patch Panels" note will have something like this: "PP#1-10 - PP#3-11 (patch to PP#1-9)" for the designation on patch panel one port 10, and I will have "PP#1-9 - PP#2-6 (patch to PP#1-10)" for patch panel one port 9.  Note that this shows where my patch cables are and how they connect.  I can always go to the "Patch Panels" note and trace from one point to another to understand where the cable ends.
  • If I move/remove the patch cable from a patch panel, then I can simply modify a couple of lines to show how things are connected.  Again, the idea is to be able to trace to the end.
  • Note that I do not list any patch cables from devices that are plugged into a port on one end or the other.
-- Cable Connections
  • The "Cable Connections" note is where I list the patch cable connections to devices.  It also designates a logical connection to an end point.  Normally there would be a patch cable from a device, and on the other end of the trace there would be a connection to a different device.
  • The "Cable Connections" note is grouped by device which allows me to immediately find out where the device is connected by port number.
  • In the "Cable Connections" note I describe on a device port where the connection ends up.  For instance, I have a connection from my main switch which is a "trunk" connection to another switch.  The way that I write it is as follows, using the last portion of the switch IP addresses:  ".119-15 - to PP#3-23 -> .118-1 [6/T]" which is a shorthand way of listing where the connection ends up, even though the actual trace through my network goes through 3 patch panels.  I can trace the physical connections through the "Patch Panels" listing and I note the vlan trunk elements (a tip on vlan nomenclature is here).  Correspondingly, I look at the port for the receiving switch and it looks like this: ".118-1 - to PP#4-X -> .119-15 [6/T]" which indicates the reverse direction.  Again, I can look through the "Patch Panels" listing and discover the physical connections through my network.
-- Home Vlans

  • The "Home Vlans" note is where I give a listing of each vlan used in my network, including why I have the vlan, what DHCP server address is used, and what DNS server address(s) are used.
  • The "Home Vlans" note also contains a line which lists the trunk line vlans for the normal case.



Thursday, June 18, 2020

Tips #2 - Network Journal

Having been an engineer for the last 45 years, I do keep track of what I do in my network.  This includes how I wire up things and why, what I do with equipment, things that I am thinking of doing, future projects, documenting current projects, and software changes.  I use a manually maintained engineering notebook format to do this.  In my case, I call it a Network Journal.  I use the following format (based on the principle of linked lists and indexes) when documenting stuff in the Network Journal (it just works for me):

  1. I always use quad ruled composition books for my notebooks.  The quad rule gives something for the eye to use when drawing diagrams.
  2. Each page in the notebook needs to have a number starting from 0.  The page numbers provide an easy reference point when indexing.
  3. Page 0 is reserved for a Table of Contents.
  4. The title of the notebook in our case is "Network Journal".  In general, I title each notebook with the subject that the notebook contains.  If this is the second notebook in the subject, it would be titled "Network Journal 2".  Write it in ink.
  5. The notebook should be individually numbered, I like to use an abbreviation of the subject, in caps, with a dash and a number.  In this case the number of the notebook would be "NETJRN-1" with "NETJRN-2" for the second notebook in the subject.  It should be written on the front of the notebook and also written across the bottom of the notebook (there should be enough space to write this when holding the pages together.  The purpose is to be able to see the number if the notebook is laid down or is stored vertically in a page sorter used for storing multiple notebooks on different subjects.
  6. The rule when referencing page numbers is that if it is in the same notebook you use the page number alone.  If it references a page in a different notebook you reference the notebook number a slash and the page number in that notebook.  If I reference page 53 in the same notebook, it is "->53".  However, if I reference page 87 in a different notebook, say "NETJRN-1" then I use "->87/NETJRN-1".  In this manner I can reference things in all of my notebooks from each other.
  7. One specific rule is that I never erase a page in a notebook.  I keep it for posterity, including references.
  8. When I put an index on a page, I title the index drawn on a line about 3/4 of an inch below the top.  I underline the title, and put the date that I started the index in the margin to the left.  If this index is a continuation of an index, I use the same title, but reference the page that has the previous index by a back arrow ("<-page_number") with a box around it.  If this index is a lower hierarchy from the previous index, I use an up arrow curving left ("<-|page_number") to reference the page.   Note that if I continue the index to a different page, I use an arrow pointing to the page and draw a box around it - "->page_number".
  9. An item to me is an individual thing that I wish to keep track of by referencing it from an index.  This could be meeting minutes if I discuss something with someone, an idea that I want to expand upon, a specific change that I am making to cabling, a new vlan and a description of its purpose, etc.  This includes text, drawings, portions of pages that have been scanned.  Each item has a title and that title should be on the same page
  10. When I add an item to an index page, I put the title that I have used on the page in the notebook, put the date in the left hand column, and on the same line I point to the page that the item occurs on "->page_number".  This way I can simply look down the page and go right to the page number of the item I am interested in reviewing.
  11. Likewise when items go on a page, if this is the first thing on the page - I put the topic of the index that this page refers to at the very top of the page (if it is not there already).  Note, I limit it to one index topic per page to ensure that everything on the page is of the same index topic.  If there is already some items on the page for the same topic, I draw a line across and continue after the line on the same page.  I start with the title underlined, with the date in the left hand margin, then I put an up arrow curving left ("<-|page_number") with the page of the index that refers to this item.
  12. If I need to continue the item on a different page, I just put an arrow pointing to the page I am continuing on and form a box around it ("->page_number").  Then I repeat on the new page.  Note that I don't have to use the very next page, I can even go backwards if necessary.



Tips #1 - Patch Panels and Markings

In my network, I have found that the best way to maintain my understanding of how my house is wired with Ethernet is how that I document my Patch Panels.  I have a few rules that maintain a cohesiveness to this:

  • Patch Panels serve to be the ends of Ethernet wires.  In general, I will not have a stray Ethernet cable coming out of a wall.
  • I use keystones in all patch panels.  This gives me the choice of terminating Ethernet wires either in a punch-down keystone, or a straight through keystone which has an Ethernet female on both sides.  
  • The advantage with using keystones is that they are easy to move around in a patch panel, or in the case of the straight through keystone, Ethernet connections behind them.  Normally equipment moves and cables stay put; the keystones are a way of augmenting that "staying put".
  • I refer to an individual keystone as a "port" in a patch panel.  Each "port" must be numbered from 1 to the total number of ports on the patch panel.
  • All patch panels in my house are numbered.  If the patch panel serves only to connect to another patch panel on the other side of the wall, I may number it with the same number but I have to use the same "port" numbers on each side.  So if I use "port" 1 on one side, then I must use "port" 1 on the other side so there is no confusion. In this case each patch panel gets the same patch panel number.  I must also ensure that the Ethernet cable is straight through.
  • The full designated "port" identifier is patch_panel_number-port_number, e.g. PP#3-12 would refer to keystone (or "port") 12 on patch panel number 3.
  • I use a labeler to mark each "port" on each patch panel.  When I mark a specific "port" I label it with the "port" that it connects to on the other end of the Ethernet cable.  For instance, if PP#3-12 connects to PP#1-6 then on patch panel number 1, "port" 6 would be labeled PP#3-12, and on patch panel number 3, "port" 12 would be labeled PP#1-6.  That way I always know where the Ethernet cable is connected and to what patch panel.
  • If a cable is moved from one keystone to another on a patch panel, the label goes with it and I make up a new label for the port that it connects to so I am consistent.  For instance, if PP#3-12 connects to PP#1-6, and I move the Ethernet cable from port 12 to port 10 on patch panel 3, then I move the PP#1-6 label from port 12 to port 10 on patch panel 3, then I make up a new label of PP#3-10, go to patch panel 1, remove the label on port 6, and replace it with the new label of PP#3-10.  I also make note of it on any note that I have.
  • Patch panels can always be used as "patch panels", i.e. I have places on patch panels that have a patch Ethernet cable between "ports" on the same patch panel.  That way, it can form one long Ethernet connection.



Sunday, July 3, 2016

Tips #0 - Wow - Amazing Find to Convert VMWare to KVM

I just happened to have enough time over the weekend to look around for some ways to convert from multiple VMWare vmdks to qcow2 and I stumbled across this site.  Now that I have found this site I can go about getting some of my VMs into a KVM setup.  The bash code that I am using is:

#!/bin/bash
for i in *.vmdk; do qemu-img convert -f vmdk $i -O raw $i.raw; done
cat *.raw > tmpImage.raw
qemu-img convert tmpImage.raw finalImage.qcow2
rm *.raw
 
I cant tell you how much I needed to find this in order to ease the process.  Thanks to Kees Cook and muru for the code.

Also found this to convert spaces in names to underscores:


for f in *\ *; do mv "$f" "${f// /_}"; done
 
Update: I spent a good portion of the day converting VMWare VMs to qcow2 and then to KVM images.  Life is once again good to me.  I was able to get a number of different VMs related to Penetration Testing completed as well as set up a bridge that could be used for the same.