In this video, Todd Lammle continues with his subnetting practice, but this time he moves the block sizes we use for finding our subnets from the fourth octet to the third octet. You'll use the same block sizes and answers you used in the fourth octet, and the fourth octet.
- [Narrator] Let's take a look at some examples…not Class C.…Here I've got in this graphic…a network address of 172.16.0.0.…Notice this is an RFC 19/18 address for Class B 172.16…through 31 are my available networks…but in this case here we're using the first one.…My mask is 255.255.128…which is a slash 17…but the 128 here…isn't that important in the sense that we're Class B.…It doesn't make it any harder.…
My subnets are in the third octet: zero and 128.…The fourth octet are all host bits.…So as you already know,…what do you do with host bits to get your network address?…You turn them all off.…To find your broadcast address,…what do you do with host bits?…You turn them all on.…So in this case here,…my fourth octet is all host bits so I just turn them all off…to get my network address and all on so the answer is:…zero and 255 in the fourth octet here always.…
Okay, so my first subnet is zero.…My next subnet is 128.…So I put a 127 down here under the zero.…I add a dot zero and a dot 255 which is so easy to do.…My valid hosts are the numbers in between…
Author
Todd Lammle
Released
9/30/2016For more information on the CCENT exam, visit Cisco's website.
- Overview of internetworking
- Ethernet
- The TCP/IP networking model
- Easy subnetting
- VLSM
- Managing Cisco IOS
- Managing Cisco networks and devices
- IP routing
- Layer 2 switching
- VLANs and InterVLAN routing
- Security
- Network address translation
- IPv6
Skill Level Intermediate
Duration
Views
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Introduction
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Welcome54s
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The CCNA exam58s
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Lab environment overview1m 3s
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1. Internetworking
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Internetworking devices4m 20s
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2. Ethernet
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Ethernet overview2m 23s
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Ethernet addressing3m 51s
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Ethernet cables4m 55s
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3. Introduction to TCP/IP
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Overview of TCP/IP model2m 40s
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Application/process layer2m 19s
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Internet layer3m 37s
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IP addressing4m 33s
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4. Easy Subnetting
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Subnet basics1m 28s
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Subnet block sizing5m 25s
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Subnet by example5m 6s
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Class B subnetting3m 53s
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5. VLSM, Summarization, and Troubleshooting TCP/IP
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VLSM2m 38s
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VLSM by hand6m 28s
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6. Cisco Internetworking Operating System (IOS)
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Introduction to the IOS CLI3m 55s
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Basic CLI commands5m 23s
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Telnet and SSH5m 4s
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7. Managing a Cisco Internetwork
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Router and switch components2m 27s
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Configure DHCP3m 48s
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8. IP Routing
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Overview of IP routing3m 45s
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The IP routing process3m 50s
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Configure IP routing6m 41s
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Static routing5m 28s
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Default routing5m 36s
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Configure RIPv26m 52s
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Verify RIPv2 routing5m 55s
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9. Layer 2 Switching
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Configure a Catalyst switch7m 33s
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Configure port security5m 5s
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10. VLANs and InterVLAN Routing (IVR)
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Overview of VLANs3m 2s
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Configure VLANs3m 8s
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Configure trunk links5m 15s
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Configure IVR on a router2m 42s
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11. Security
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Introduction to access lists2m 24s
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Configure access lists4m 3s
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12. Network Address Translation (NAT)
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Introduction to NAT2m 18s
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Static NAT2m 53s
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Configure static NAT3m 11s
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Dynamic NAT2m 44s
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Configure dynamic NAT3m 44s
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NAT overload (PAT)3m 56s
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Configure NAT overload5m 26s
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13. IPv6
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Introduction to IPv62m 22s
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Overview of ICMPv62m 55s
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Configure IPv66m 7s
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Conclusion
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Next steps51s
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Video: Class B subnetting