Basic Network Security Volume in John R Hines’ Computer Security for Mere Mortals, short documents that show how to have the most computer security with the least effort John R Hines Net+ Certified, Security+ Certified, Consulting Security Engineer, LLC JohnRichardHines@ConsultingSecurityEngineer.com “Plagiarism is when the author steals from one source; scholarship is when the author steals from many sources.” Anonymous "Facts are stubborn things; and whatever may be our wishes, our inclinations, or the dictates of our passions, they cannot alter the state of facts and evidence." John Adams Oholiab's First Law: The Suits' need for computing power expands until all the Geeks' servers are 100% utilized running database queries and printing reports during business hours Corollary to Oholiab's First Law: Development can only access the servers purchased for development when nobody else wants them Oholiab's first law of security (Murphy's first law of planning): The important things are simple Oholiab's second law of security (Murphy's second law of planning): The simple things are very hard Oholiab's corollary to the first and second laws of security: Simple and easy are not the same thing Fools don't know the difference Warning: If you’re not smart enough to sort the cow pies from the pearls in these notes, you not have permission to read these notes! Copyright © Consulting Security Engineer LLC All rights reserved 2016 ISBN N/A Version 1.201708212300 Suggested reading (when you have time) Kill Process by William Hertling Security by Poul Anderson badly formatted but great ideas Table of Contents Suggested reading (when you have time) Revision History Security Is security a new problem? What is security? What is computer security? What is in these notes? Networks Why care about networks? What these notes assume you've already done? What simple reasonable measures will improve security on your intranet? Measure #1: Have two routers: one for business use and one for all other uses Measure #2: Have at least one old slow network computer for nonbusiness (and for friends and family) use Measure #3: Shutdown the business (secure) router when no one is the office Measure #4: Shutdown the risky (insecure) router when no one should be on the internet Measure #5: Do a quick walk about every quarter (when the season changes) (when TV switches to a different major sport) Measure #6: Do a quick audit of all computers about every quarter (when the season changes) (when TV switches to a different major sport) Appendices Appendix I: Network basics What is a cable modem? What is a network (computer network)? What is broadband (wideband)? What is IP (Internet Protocol)? What is the internet (Internet) (public network)? What is TCP (Transmission Control Protocol)? What is WIFI (Wi-Fi) (Wifi) (WiFi) (Wireless networking) (Unbounded media)? What is wired (hard-wired)? What is wireless? Appendix II: Common network utilities What is the command window (command box) (DOS box)? Ipconfig (IPCONFIG) Nbtstat Net (Net services) Netstat (netstat) (network statistics) nslookup (Nslookup) (NSLOOKUP) Appendix III: Why I care about intranets? Appendix III: Using ipconfig to find basic network information How I open a Command window (Command box) (DOS box) PowerShell window? How I find out what IP and what router my PC is using? What is a command window (command box) (DOS box) (PowerShell window)? Appendix IV: Use Nmap with Zenmap GUI to find out what your intranet looks like? How I use nmap to find out what my network looks like? What does Nmap/Zenmap tell me about my home network? What is Nmap? What documents are part of this series? Biography Revision History Rev Change 1.0 Created and published document Security Is security a new problem? No! Security has always been a problem! Even strong men have security concerns: "When the strong man, fully armed, guards his own dwelling, his goods are safe But when someone stronger attacks him and overcomes him, he takes from him his whole armour in which he trusted, and divides his spoils." (Luke 11:21-22) Criminals form gangs to defeat strong men Captain Grose' 1811 Dictionary of the Vulgar Tongue (nineteenth century lexicographer) lists 23 occupations required for a complete "gang of misrule" (crime family) My dictionary gives these as " … For men, there are fourteen roles: (1) ruffler, (2) upright man, (3) hooker (angler), (4) rogue, (5) wild rogue, (6) priggers of prancers, (7) palliards, (8) frater, (9) jarkman (patricoe) (10) whip jacket, (11) drummerer (dommerer), (12) drunken tinker (13) swadder (pedlar), and (14) Abram man For women (and children) there are nine roles: (1) demander for glimmer or fire, (2) bawdy basket, (3) morts, (4) autem mort, (5) walking morts (6) doxy, (7) dell, (8) kinching mort, and (9) kinching cove." (Buy my book if you want to know what all these specialties are.) Add hackers and testers and you have the kind of crime family HP describes in The Business of Hacking, capable of stealing from the strong as well as the weak What is security? The dictionary definition of security is "being free from danger or threat" Experience indicates no one is secure, at least in the dictionary sense Solomon had a different take on security (or, maybe, on the lack of security): "The race is not to the swift or the battle to the strong, nor does food come to the wise or wealth to the brilliant or favor to the learned; but time and chance happen to them all" (NIV) (Bumper stickers on the back of pickups summarize Solomon's quote in two words: "Excrement happens".) Damon Runyon, writer of "Guys and Dolls" offered an amendment to Solon's advice: " The race is not always to the swift, nor the battle to the strong, but that's the way to bet." The way to be secure is to be good and hope to be lucky And, (if you've read any of Runyon's other works), the way not to be secure to be not good (unless you're very, very lucky) So, I suggest a different definition of security that emphasizes our part in keeping ourselves secure: "things done and things left undone that give as much control as possible over the future" Be good (the things done), be careful (the things not done), and hope to be lucky One more quote: "Luck is what happens when preparation meets opportunity" (Seneca, First Century AD, possibly misattributed) Prepare for Murphy to knock on your door A disaster for the unprepared is an opportunity for the prepared What is computer security? The dictionary says, "measures taken to safeguard code, information, and systems" A more sensible definition of computer security is "(1) reasonable measures taken to safeguard code, information, and systems, (2) unreasonable measures not taken to safeguard code, information, and systems, and (3) measures not taken to avoid low-rewards." Unfortunately, reasonable, unreasonable, and low-reward are (like beauty) in the mind of the beholder What is in these notes? I'm going to tell you what I think are reasonable and unreasonable measures and what are low-reward measures What is a low-reward measure? A security measure that that has a small payoff for the inconvenience, money and time associated with the measure Most of the measures advocated by security professionals a low-reward measures What is a reasonable measure? A security measure that that has a significant payoff for the inconvenience, money and time associated with the measure Reasonable measures that are not terribly inconvenient for a nonprofessional and require little money and time should ALWAYS be implemented Reasonable measures that are terribly inconvenient for a nonprofessional but require only a small amount of time and money should be implemented when possible (Maybe hire a professional for a halfday?) Reasonable measures that are not inconvenient for a non-professional but require a small amount of time and money should be implemented when possible (I define a small amount of money as my monthly business cell phone and internet bill You may have a different definition.) Reasonable measures that are terribly inconvenient for a nonprofessional and require a lot of money should only be implemented if you have suspect you are a potential target Warning: If you are (1) involved in politics or social issues, (2) are visible in your community for some reason, or (3) have strange family members or neighbors then you should suspect you are a target What is an unreasonable measure? A security measure that that has become popular wisdom but probably is of little value (A few years ago, one argument for switching from a PC to a Mac was "Macs don't get viruses." If that was ever true, it isn't now but many Mac sales people and users still believe it and repeat it to non-Mac users.) Send me an email at JohnRichardHines@ConsultingSecurityEngineer.com to let me know when I'm wrong Thanks, John Networks Why care about networks? If you use the internet, you're on a network If you use the internet at work, at a library, at a restaurant or whoever supplies the connection (hopefully) has a professional who takes care of network details for you However, if you use the internet at home or at your small business, you have a small network (an intranet) in your home If all you have is a direct wired connection to the internet no WIFI then the intranet is just your cable modem and your computer and your problems are small As soon as you add a router to your intranet you have (potential) network problems So, you need to know enough to basic security stuff What these notes assume you've already done? The notes assume you have read "Computer security: a 15-minute talk" and have already implemented the security measures described in "Basic Windows 10 Security" and "Basic Phone and Tablet Security" Also, if you have a router in addition to your cable modem, they assume you have implemented the security measures in "Basic Router Security" These notes will still be useful if you have not implemented the measures above but you will have holes in your security Caveat emptor! Note: All these notes are available as eBooks on Amazon.com Search the Kindle area for "John R Hines" Setclassid Managing DHCP server Seldom used (/setclassid), ipconfig /setclassid showclassid (/showclassid) Nbtstat Windows diagnostic tool for NetBIOS that troubleshoot NetBIOS name resolution problems Seldom used Net (Net services) Performs a broad range of network tasks Type net with no parameters to see a full list of available command-line options Typical syntax is NET [ ACCOUNTS | COMPUTER | CONFIG | CONTINUE | FILE | GROUP | HELP | HELPMSG | LOCALGROUP | PAUSE | SESSION | SHARE | START | STATISTICS | STOP | TIME | USE | USER | VIEW] NET ACCOUNTS NET COMPUTER NET CONFIG NET CONTINUE NET FILE NET GROUP NET HELP NET HELPMSG NET LOCALGROUP NET NAME NET PAUSE NET SESSION Change account settings Add and remove other networked computers Displays current SERVER or WORKSTATION Continue using SERVICE Display all the open shared files on a server and the lock-id Manage network workgroups Manage network groups Manage messaging name Pause service List all sessions on current machine NET SESSION \\ComputerName: NET SHARE sharename NET START NET STATISTICS NET STOP NET TIME NET USE NET USER NET VIEW List sessions from a given machine Manage local share Start service Display network statistics for WORKSTATION or SERVER Stop service Display date/time of another computer Connects / disconnects the computer from a shared resource or view the information about current computer connections Displays users Display computers in the local domain See shares on computer NET VIEW \\ComputerName Netstat (netstat) (network statistics) Displays network connections for Transmission Control Protocol (both incoming and outgoing), routing tables, and a number of network interface (network interface controller or software-defined network interface) and network protocol statistics -a state of all sockets -b displays executable creating connection -n shows network addresses as numbers -o displays owning process nslookup (Nslookup) (NSLOOKUP) Network administration command-line tool available for many computer operating systems for querying the DNS to obtain domain name or IP address mapping or other specific DNS records To access help, type nslookup [CR] When the nslookup prompt appears, enter "?"/ Appendix III: Why I care about intranets? If you have a home connection to the internet, you automatically have an intranet in your home, although it may be a (very) small intranet (If all you have is a wired connection to the internet no WIFI then the intranet is just your cable modem and your computer.) As soon as you add a router to your intranet, you have an intranet with (potential) network problems Appendix III: Using ipconfig to find basic network information How I open a Command window (Command box) (DOS box) PowerShell window? Right click on the windows flag then click on the Windows PowerShell (Admin) entry In earlier versions, click on the Command (Admin) entry How I find out what IP and what router my PC is using? Open a PowerShell Window (Admin) Type [ipconfig What is a command window (command box) (DOS box) (PowerShell window)? In Windows, a popup window that acts (somewhat) like the (now obsolete) DOS command line where the user enters instructions from the keyboard Warning: The "admin" version allows adminequivalent users to run most commands; the standard version limits what the user can even if he is also an admin-equivalent under another user name Click on the "YES" button when Windows 10 asks you if you want to allow this application to changes things Soon, a small blue window with a command prompt will pop up Type "ipconfig" then press [ENTER] The IPv4 entry shows the workstation IP address on the intranet The Default Gateway entry shows the gateway (router that connects the intranet to the internet) The Subnet Mask says the intranet is 192.168.1.0-255 Write these numbers down on a piece of scrap paper You may want them later Appendix IV: Use Nmap with Zenmap GUI to find out what your intranet looks like? How I use nmap to find out what my network looks like? Before you start, make sure every device on your network and every device attached to your intranet by USB is turned on BTW: This includes phones and tablets attached by USB cables Note: Nmap is not going to detect devices attached to your network by Start Zenmap as an admin-equivalent When a full-screen window pops up asking you if Zenmap can make changes, click on "Yes" The Zenmap window will pop up Enter the intranet addresses (192.169.1.0-255) you got from ipconfig and click on the "SCAN" button Wait patiently: The scan will take multiple minutes When done, you can look at the Nmap/Zenmap results by clicking on the various Zenmap tabs What does Nmap/Zenmap tell me about my home network? Hosts found by Nmap/Zenmap displayed in Zenmap host viewer Services found by Nmap/Zenmap displayed in "Services" tab Ports on hosts found by Nmap/Zenmap in Hosts Ports/Hosts tab Network image found by Nmap/Zenmap in Hosts Topology Fisheye tab Output found by Nmap/Zenmap in Hosts Nmap Output tab When the scan is done, you will something like this: Starting Nmap 7.60 ( https://nmap.org ) at 2017-08-19 14:12 Central Daylight Time NSE: Loaded 146 scripts for scanning NSE: Script Pre-scanning Initiating NSE at 14:12 Completed NSE at 14:12, 0.00s elapsed Initiating NSE at 14:12 Completed NSE at 14:12, 0.00s elapsed Initiating ARP Ping Scan at 14:12 Scanning 255 hosts [1 port/host] Completed ARP Ping Scan at 14:12, 2.84s elapsed (255 total hosts) Initiating Parallel DNS resolution of 255 hosts at 14:12 Completed Parallel DNS resolution of 255 hosts at 14:12, 5.53s elapsed Nmap scan report for 192.168.1.0 [host down] Nmap scan report for 192.168.1.1 [host down] //removed unneeded information Nmap scan report for 192.168.1.63 [host down] //found some hosts ß 192.168.1.64, 65, 66 Nmap scan report for 192.168.1.67 [host down] Nmap scan report for 192.168.1.68 [host down] //found some hosts ß 192.168.1.69 Nmap scan report for 192.168.1.70 [host down] //removed unneeded information Nmap scan report for 192.168.1.253 [host down] //found host ß 192.168.1.254 Nmap scan report for 192.168.1.255 [host down] Initiating Parallel DNS resolution of host at 14:12 Completed Parallel DNS resolution of host at 14:13, 5.51s elapsed Initiating SYN Stealth Scan at 14:13 Scanning hosts [1000 ports/host] Discovered open port 443/tcp on 192.168.1.254 Discovered open port 80/tcp on 192.168.1.254 Discovered open port 49152/tcp on 192.168.1.254 Completed SYN Stealth Scan against 192.168.1.254 in 0.83s (4 hosts left) ß Discovered open port 554/tcp on 192.168.1.64 Discovered open port 2869/tcp on 192.168.1.64 Discovered open port 10243/tcp on 192.168.1.64 Discovered open port 5357/tcp on 192.168.1.64 Completed SYN Stealth Scan against 192.168.1.64 in 13.35s (3 hosts left) ß Completed SYN Stealth Scan against 192.168.1.66 in 13.79s (2 hosts left) ß Completed SYN Stealth Scan against 192.168.1.73 in 13.79s (1 host left) ß Completed SYN Stealth Scan at 14:13, 16.88s elapsed (5000 total ports) Initiating Service scan at 14:13 Scanning services on hosts Completed Service scan at 14:15, 106.16s elapsed (7 services on hosts) Initiating OS detection (try #1) against hosts Retrying OS detection (try #2) against hosts NSE: Script scanning hosts Initiating NSE at 14:15 Completed NSE at 14:16, 64.79s elapsed Initiating NSE at 14:16 Completed NSE at 14:16, 1.02s elapsed Nmap scan report for DESKTOP-NSCEFQ7 (192.168.1.64) Host is up (0.0017s latency) Not shown: 996 filtered ports PORT STATE SERVICE VERSION 554/tcp open rtsp? 2869/tcp open http Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP) 5357/tcp open http Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP) |_http-server-header: Microsoft-HTTPAPI/2.0 |_http-title: Service Unavailable 10243/tcp open http Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP) |_http-server-header: Microsoft-HTTPAPI/2.0 |_http-title: Not Found MAC Address: 2C:27:D7:1C:D7:AC (Hewlett Packard) Warning: OSScan results may be unreliable because we could not find at least open and closed port Device type: general purpose Running (JUST GUESSING): FreeBSD 6.X (91%), Microsoft Windows 2008 (87%) OS CPE: cpe:/o:freebsd:freebsd:6.2 cpe:/o:microsoft:windows_server_2008::beta3 cpe:/o:microsoft:windows_server_2008 Aggressive OS guesses: FreeBSD 6.2-RELEASE (91%), Microsoft Windows Server 2008 or 2008 Beta (87%) No exact OS matches for host (test conditions non-ideal) Uptime guess: 1.701 days (since Thu Aug 17 21:26:18 2017) Network Distance: hop TCP Sequence Prediction: Difficulty=253 (Good luck!) IP ID Sequence Generation: Incremental Service Info: OS: Windows; CPE: cpe:/o:microsoft:windows TRACEROUTE HOP RTT ADDRESS 1.75 ms DESKTOP-NSCEFQ7 (192.168.1.64) Nmap scan report for Tenda (192.168.1.66) Host is up (0.0011s latency) Not shown: 999 filtered ports PORT STATE SERVICE VERSION 1723/tcp closed pptp MAC Address: C8:3A:35:19:BC:C9 (Tenda Technology) Too many fingerprints match this host to give specific OS details Network Distance: hop TRACEROUTE HOP RTT ADDRESS 1.06 ms Tenda (192.168.1.66) Nmap scan report for android-da7c67eef6602955 (192.168.1.69) Host is up (0.083s latency) All 1000 scanned ports on android-da7c67eef6602955 (192.168.1.69) are filtered MAC Address: DC:66:72:23:97:D7 (Samsung Electronics) Too many fingerprints match this host to give specific OS details Network Distance: hop TRACEROUTE HOP RTT ADDRESS 83.00 ms android-da7c67eef6602955 (192.168.1.69) Nmap scan report for DESKTOP-OR5KQ2L (192.168.1.73) Host is up (0.00s latency) All 1000 scanned ports on DESKTOP-OR5KQ2L (192.168.1.73) are filtered MAC Address: 00:26:55:3B:E0:F8 (Hewlett Packard) Too many fingerprints match this host to give specific OS details Network Distance: hop TRACEROUTE HOP RTT ADDRESS 0.00 ms DESKTOP-OR5KQ2L (192.168.1.73) Nmap scan report for homeportal (192.168.1.254) Host is up (0.0028s latency) Not shown: 997 closed ports PORT STATE SERVICE VERSION 80/tcp open http 2Wire HomePortal router http config |_http-title: Home 443/tcp open ssl/http 2Wire HomePortal router http config | ssl-cert: Subject: commonName=attlocal.net/organizationName=2Wire/countryName=US | Issuer: commonName=Gateway Authentication/organizationName=2Wire/countryName=US | Public Key type: rsa | Public Key bits: 1024 | Signature Algorithm: sha1WithRSAEncryption | Not valid before: 2015-12-22T16:35:31 | Not valid after: 2031-01-17T16:35:31 | MD5: f65d dfe1 004d 6764 7a75 c15d da64 b265 |_SHA-1: e1aa f90f ba4c 63ad d62f be75 a218 1aa9 42f4 524c 49152/tcp open tcpwrapped MAC Address: E0:22:03:D6:83:A5 (Unknown) Device type: general purpose Running: Linux 2.6.X OS CPE: cpe:/o:linux:linux_kernel:2.6 OS details: Linux 2.6.9 - 2.6.27 Uptime guess: 1.699 days (since Thu Aug 17 21:29:33 2017) Network Distance: hop TCP Sequence Prediction: Difficulty=193 (Good luck!) IP ID Sequence Generation: All zeros Service Info: Device: broadband router TRACEROUTE HOP RTT ADDRESS 2.79 ms homeportal (192.168.1.254) Initiating SYN Stealth Scan at 14:16 Scanning SCE-10Pro-Workstation (192.168.1.65) [1000 ports] Discovered open port 445/tcp on 192.168.1.65 Discovered open port 554/tcp on 192.168.1.65 Discovered open port 135/tcp on 192.168.1.65 Discovered open port 139/tcp on 192.168.1.65 Discovered open port 2869/tcp on 192.168.1.65 Discovered open port 10243/tcp on 192.168.1.65 Discovered open port 5357/tcp on 192.168.1.65 Completed SYN Stealth Scan at 14:16, 0.36s elapsed (1000 total ports) Initiating Service scan at 14:16 Scanning services on SCE-10Pro-Workstation (192.168.1.65) Completed Service scan at 14:18, 106.04s elapsed (7 services on host) Initiating OS detection (try #1) against SCE-10Pro-Workstation (192.168.1.65) Retrying OS detection (try #2) against SCE-10Pro-Workstation (192.168.1.65) NSE: Script scanning 192.168.1.65 Initiating NSE at 14:18 ß Completed NSE at 14:19, 65.21s elapsed Initiating NSE at 14:19 ß Completed NSE at 14:19, 1.00s elapsed Nmap scan report for SCE-10Pro-Workstation (192.168.1.65) Host is up (0.000080s latency) Not shown: 993 closed ports PORT STATE SERVICE VERSION 135/tcp open msrpc Microsoft Windows RPC 139/tcp open netbios-ssn Microsoft Windows netbios-ssn 445/tcp open microsoft-ds Windows 10 Pro 15063 microsoft-ds (workgroup: WORKGROUP) 554/tcp open rtsp? 2869/tcp open http Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP) 5357/tcp open http Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP) |_http-server-header: Microsoft-HTTPAPI/2.0 |_http-title: Service Unavailable 10243/tcp open http Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP) |_http-server-header: Microsoft-HTTPAPI/2.0 |_http-title: Not Found Aggressive OS guesses: Microsoft Windows 10 10586 - 14393 (96%), Microsoft Windows 10 build 10074 - 14393 (96%), Version 6.1 (Build 7601: Service Pack 1) (96%), Microsoft Windows 10 build 10586 (95%), Microsoft Windows 10 build 15031 (95%), Microsoft Windows 10 (93%), Microsoft Windows Longhorn (93%), Microsoft Windows Server 2008 (93%), Microsoft Windows Server 2016 build 10586 (93%), Microsoft Windows Professional (93%) No exact OS matches for host (test conditions non-ideal) Uptime guess: 0.026 days (since Sat Aug 19 13:41:40 2017) Network Distance: hops TCP Sequence Prediction: Difficulty=259 (Good luck!) IP ID Sequence Generation: Incremental Service Info: Host: SCE-10PRO-WORKS; OS: Windows; CPE: cpe:/o:microsoft:windows Host script results: | smb-os-discovery: | OS: Windows 10 Pro 15063 (Windows 10 Pro 6.3) | OS CPE: cpe:/o:microsoft:windows_10::| Computer name: SCE-10Pro-Workstation | NetBIOS computer name: SCE-10PRO-WORKS\x00 | Workgroup: WORKGROUP\x00 |_ System time: 2017-08-19T14:18:11-05:00 | smb-security-mode: | account_used: | authentication_level: user | challenge_response: supported |_ message_signing: disabled (dangerous, but default) | smb2-security-mode: | 2.02: |_ Message signing enabled but not required | smb2-time: | date: 2017-08-19 14:18:13 |_ start_date: 2017-08-19 13:42:10 NSE: Script Post-scanning ß Initiating NSE at 14:19 Completed NSE at 14:19, 0.00s elapsed Initiating NSE at 14:19 Completed NSE at 14:19, 0.00s elapsed Read data files from: C:\Program Files (x86)\Nmap OS and Service detection performed Please report any incorrect results at https://nmap.org/submit/ Nmap done: 256 IP addresses (6 hosts up) scanned in 388.85 seconds Raw packets sent: 10799 (489.882KB) | Rcvd: 3247 (143.088KB) What is Nmap? An open source command-line scanner Zenmap is a GUI for Nmap Try https://nmap.org/ What documents are part of this series? Volume 1: 5-Minute security talk Volume 2: 15-Minute security talk Volume 3: Basic Windows 10 Security Volume 4: Basic Router Security Volume 5: Basic Network Security Volume 6: Basic Browser Security Volume 7: Advanced Windows 10 Security Volume 8: Advanced Router Security Volume 9: Advanced Network Security Volume 10: Advanced Browser Security Volume 11: Basic Windows Security Volume 12: Basic Phone and Tablet Security Volume 13: Advanced Phone and Tablet Security Volume 14: Basic eMail Security Volume 15: Advanced eMail Security Volume 16: Basic Developing Secure Apps Biography John R Hines has degrees from two party schools (the University of Colorado and Arizona State University) He was a professional engineer in Texas He has been a semiconductor engineer, a programmer, a writer and a teacher Since he retired to Lucas, Texas, he has been writing eBooks for Amazon and thinking about computer security and taking CompTIA certification tests (he is A+, Net+, and Security+ certified) In the 1980s, the US Patent and Trademark Office granted him six patents and he began writing about using computers to solve problems He wrote a book about circuit simulation and taught SPICE (Simulation Program with Integrated Circuit Emphasis) classes at Fortune 500 companies In the 1990s, he had computer-related columns in popular trade magazines like Electronic Test and Design Automation and scholarly magazines like IEEE Spectrum and taught C, C++, Delphi and Java In the 2000s, he was a Java developer for America’s best telephone company In late 2016, he started prototyping a security start-up to test a business model for geek geezers who want to work less than 20 hours a week Google him under JR Hines, J Richard Hines (Honeywell did not want him writing under his usual name), John Hines and John R Hines Or look at his computer books on Amazon.com ... for Transmission Control Protocol (both incoming and outgoing), routing tables, and a number of network interface (network interface controller or software-defined network interface) and network. .. Had to replace the router and had to retrain the granddaughter since my wife would let me replace the granddaughter.) Check your secure place Is the secure information storage container still there?... "ipconfig" then press [ENTER] The IPv4 entry shows the workstation IP address on the intranet The Default Gateway entry shows the gateway (router that connects the intranet to the internet) The Subnet