CCNA 4-2 VLSM.ppt

? 2007 Cisco Systems, Inc. All rights reserved. ICND2 — 3-1 Medium-Sized work Construction Implementing VLSM ? 2007 Cisco Systems, Inc. All rights reserved. ICND2 — 3-2 ting Review To identify s, you will “ borrow ” bits from the host ID portion of the IP address: ? The number of s available depends on the number of bits borrowed. – The available number of s = 2 s , I which s is the number of bits borrowed. ? The number of hosts per available depends upon the number of host ID bits not borrowed. – The available number of hosts per = 2 h -2, in which h is the number of host bits not borrowed. – One address is reserved as work address. – One address is reserved as the broadcast address. ? 2007 Cisco Systems, Inc. All rights reserved. ICND2 — 3-3 Possible s and Hosts for a Class work ? 2007 Cisco Systems, Inc. All rights reserved. ICND2 — 3-4 Possible s and Hosts for a Class work ? 2007 Cisco Systems, Inc. All rights reserved. ICND2 — 3-5 Possible s and Hosts for a Class work ? 2007 Cisco Systems, Inc. All rights reserved. ICND2 — 3-6 ting Review Exercise work with a work address of ./16 so that it provides 100 s and maximizes the number of host addresses for each . ? How many bits will need to be borrowed? ? What is the new mask? ? What are the first four s? ? What are the range of host addresses for the four s? ? 2007 Cisco Systems, Inc. All rights reserved. ICND2 — 3-7 What Is a Variable-Length Mask? is divided into smaller s. – with one mask (/ 27). – Then further one of the unused /27 s into multiple /30 s. ? 2007 Cisco Systems, Inc. All rights reserved. ICND2 — 3-8 A Working VLSM Example ? 2007 Cisco Systems, Inc. All rights reserved. ICND2 — 3-9 A Working VLSM Example (Cont.) ? 2007 Cisco Systems, Inc. All rights reserved. ICND2 — 3- 10 A Working VLSM Example (Cont.)