Network Plus IP Addressing Review

1/28/20101/28/2010Network PlusIP Addressing Review

IP Address Classes

Reserved IP Addresses RangesAddresses cannot be all 1sConsidered broadcast

Loopback address127.x.y.z

Private IP address reserved for LAN, not routable across Internet BGP routers.

Private IP Address Ranges

Subnet Masking

Default Subnet MasksClassful Default MasksClass A: 255.0.0.0Class B: 255.255.0.0Class C: 255.255.255.0Classless Default MasksClass A: /8Class B: /16Class C: /24SubnettingIP Address: 192.168.1.x/24Default Mask: 255.255.255.0 Create 3 subnetsMask: 255.255.255.22411100000 = 128+64+32 = 224Subnet numbers:001, 010, 100Computer address 1 on subnet 001192.168.1.33Computer address 1 on subnet 010192.168.1.65

Super-NettingPut more computers on subnet than default mask would allowExample: Need 300 computers on 192.168.4.x/24Subnet Mask (move to the left 1 bit)255.255.254.0 or /23Computer addresses:192.168.00000100.00000001 192.168.4.1192.168.00000101.111111110 192.168.5.254

Planning IP AddressesNecessary IP Address components:IP AddressSubnet MaskDefault Gateway

IP ConfigurationGateway and all computers must have same IP network address on the switchGateway has public IP address on Internet portComputer uses Subnet Mask to check destination against its IP address. If on same network, ARP and get MAC address of receiver. If on different networks, sends packet to the gateway.

Computer IP Configuration SettingsIP Address: 192.168.4.1Mask: 255.255.255.0Default Gateway: 192.168.4.10

IP Assignment MethodsStaticUsed by devices such as Printers, Servers, RoutersAssignment method depends on device or computer OSDynamicBootP (Bootstrap Protocol)DHCP (Dynamic Host Configuration Protocol)APIPA (Automatic Private IP Addressing)Static IP Assignment

DHCPClient makes requrest.DHCP Server makes IP lease assignment from a range of IP addresses called a scopeLease must be renewed within specified period (days or hours)Provides multiple parameters

APIPAAutomatic Private IP AddressingUsed by Windows when no response from DHCP serverMicrosoft StandardApple has similar process called RendezvousAddress range:169.254.x.yDoes not use GatewayWhen you see a computer with this address it may have experienced problem connecting to DHCP server such as if a users turns on computer before WAP IPv6 Address OverviewComposed of 8 16-bit fields (128-bits)Each 16-bit field represented by 4 Hex digits separated by colons.F:F:0:0:0:0:3012:0CE3 same as 000F:000F:0000:0000:0000:0000:3012:0CE3A string of 0000 fields may be represented by a double ::F:F::3012:CE3 ( in shorthand) Because there are 8 16 bit fields, it is assumed 4 fields of 0000 between the ::Loopback address = ::1 (0000:0000:0000:0000:0000:0000:0000:0001)

IPv6 Address SpecificationsAddress reflects scope of transmissions recipients:First 64 bits is the network and last 64 bits is the hostUnicast address local addressStarts with FEC or FE8 Public Internet start with 2 or 3Anycast address represents any one interface from a group of interfacesMulticast address:Starts with FF0x x is the group idGlobal multicastStarts with FF0E

5/6/2013IPv6 Address ScopesUnicast address (link-local)FE80: (link-local packet not routable)1111 1110 10 (FE8, FE9, FEA or FEB)FEC0:.. (site-local not routable on public Internet)1111 1110 11 (FEC, FED, FEE or FEF)Nnnn: (Internet)MulticastSend to all computers in a multi-cast groupFF0x: (x represents the multicast group)Anycast addressStandard unicast address assigned to multiple machinesUsed with routers to all nearest router to accept the packetPacket can be accepted by first available device

5/6/2013IPv6 Address Types

Link Scope

5/6/2013Aggregatable Global AddressUsed on Public Internet routers Designed from its foundation to support efficient, hierarchical addressing and routingSummarized to produce an efficient routing infrastructureStart with 001 in first three bits. (2:: or 3::)5/6/2013

5/6/2013IPv6 SubnettingDoes not use Classes every IPv6 address is classlessNo subnet masksFirst 64-bits network id (Subnet Prefix) and last 64-bits is the interface id.Interfaces that share subnet prefix on same subnet5/6/2013

Route PrefixInterfaces that belong to same routeVary in length defined by /2608:FE10::/32Example:National NSP assigns regional ISP 32-bit route: 2608:FE10::/32Regional ISP assigns a local ISP a 48-bit route block prefix: 2608:FE10:1::/48Local ISP assigns business 2608:FE10:1:A::/64

5/6/2013Thats all folks