Internet Protocol (IP): IP Address
Teknologi Jaringan Komputer Johny Moningka (
[email protected]) Fakultas Ilmu Komputer Universitas Indonesia Semester 2003/2004 Versi: 1.01
Supplement Sumber Materi: 2000–2003 © Michael E. Thomadakis http://courses.cs.tamu.edu/miket/cpsc612
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Versi: 1.1
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“Class-full” Addresses Properties Global address (public), unik; hierarchical: network + host
• Dot Notation – 10.3.2.4 – 128.96.33.81 – 192.12.69.77
Five classes of IP addresses “Classful Addressing” 8 16 Bit position:0 1 2 3 Host ID Class A 0 Net ID Net ID
31
Host ID
Class B
1 0
Class C
1 1 0
Class D
1 1 1 0
Multicast Address
Class E
1 1 1 1
Reserved for Experiments
Net ID
Host ID
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Versi: 1.1
IP Addresses Ranges by Class IP
Addresses occupy the following valid ranges according to Class
class A
0 network
B
10
C
110
D
1110
host
network
host
network multicast address
32 bits
4
host
1.0.0.0 – 127.255.255.255 128.0.0.0 – 191.255.255.255 192.0.0.0 – 223.255.255.255 224.0.0.0 – 239.255.255.255
Versi: 1.1
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IP Addressing – Introduction IP Address: a unique 32-bit identifier for host, router interface (dapat lebih dari satu interface) Interface (i/f): attachement of host / router to physical link Interface terhubung langsung dengan koneksi fisik jaringan (mis. LAN, modem, wireless dsb) Jadi sebenarnya IP addresses dikaitkan dengan interface (not host or router).
223.1.2.1
223.1.1.1 223.1.1.2
223.1.2.9
223.1.1.4
223.1.3.27
223.1.1.3
223.1.2.2
223.1.3.1
223.1.3.2
IPv4 Dot Notation 4 octets (8-bit bytes) separated by a dot 223.1.1.1 = 11011111 00000001 00000001 00000001 • 10.3.2.4 • 128.96.33.81 • 192.12.69.77
223
1 Decimal
1
1
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Versi: 1.1
IP Addressing – Hierarchy IP Address: [Network, Host] network part is a fixed size prefix (high order bits) host part the remaining bits in the IP number (low order bits)
What’s a “network” ? (from IP address perspective) Interface-interface yang memiliki IP address dgn “network part” yang sama. Forwarding paket IP dapat dilakukan secara langsung tanpa perlu dikirimkan ke router. 6
223.1.1.1
223.1.2.1
223.1.1.2 223.1.1.4
223.1.2.9
223.1.3.27 223.1.1.3
223.1.2.2
LAN 223.1.3.1
223.1.3.2
Network consisting of 3 IP networks (for IP addresses starting with 223, first 24 bits are network address) Versi: 1.1
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IP Addressing How to find the
223.1.1.1
IP networks? Pisahkan
223.1.1.2
223.1.1.4
Interconnected system consisting of six networks
223.1.1.3
setiap
223.1.7.0
223.1.9.2
interface dengan router & host => network 223.1.9.1 223.1.8.1 part yg sama. Minimal network 223.1.2.6 terdapat 2 223.1.2.1 223.1.2.2 interface (pointto-point)
223.1.7.1 223.1.8.0 223.1.3.27 223.1.3.1
223.1.3.2
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Versi: 1.1
Forwarding Datagram (1/4) IP Datagram
Routing Table in A Next Router Nhops Dest. Net.
(IPDG): misc source dest fields IP addr IP addr
223.1.1 223.1.2 223.1.3
data
A 1.
2.
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Datagram tidak mengalami perubahan selama dilakukan forwarding sampai ke tujuan. Router melihat “network part” utk melakukan forwarding
223.1.1.4 223.1.1.4
1 2 2
223.1.1.1 223.1.2.1 223.1.1.2 223.1.1.4
B
223.1.2.9 223.1.2.2
223.1.1.3 223.1.3.1
223.1.3.27
E
223.1.3.2
Versi: 1.1
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Forwarding Datagram (2/4) misc fields
223.1.1.1 223.1.1.3
Routing Table in A
data
Move IPDG from A to B: A [IP] : looks up B’s network address in RT A [IP] : finds B is on same network as A • B and A are directly connected A [LLC] link layer will send datagram directly to B inside link-layer frame • MAC addr of B’s i/f is still required to be known for the frame to reach B.
Dest. Net. next router Nhops 223.1.1 223.1.2 223.1.3
1 2 2
223.1.1.4 223.1.1.4
223.1.1.1 223.1.2.1
A 223.1.1.2 223.1.1.4
223.1.2.9
223.1.2.2
B 223.1.1.3
E
223.1.3.27 223.1.3.2
223.1.3.1
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Versi: 1.1
Forwarding Datagram (3/4) misc fields
223.1.1.1 223.1.2.2
Routing Table in A
data
Dest. Net. next router Nhops 223.1.1 223.1.2 223.1.3
Move IPDG from A to E
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look up network address of E E is on different network • A, E not directly attached A[routing table] : next hop router to E is 223.1.1.4 A[DLL] sends datagram to router 223.1.1.4 inside link-layer frame • A[LLC] must know the MAC address of this i/f of router datagram arrives at 223.1.1.4 continues on next page
223.1.1.1
223.1.2.1
A 223.1.1.2 223.1.1.4
B
1 2 2
223.1.1.4 223.1.1.4
223.1.2.9
223.1.2.2 223.1.1.3 223.1.3.1
223.1.3.27
E 223.1.3.2
Versi: 1.1
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Forwarding Datagram (4/4) misc fields
223.1.1.1 223.1.2.2
Arriving at 223.1.4,
destined for 223.1.2.2
Routing Table in Router
data
Router[IP] looks up network address of E E on same network as router’s interface 223.1.2.9 • router and E are directly attached Router[DLL] sends IPDG to 223.1.2.2 inside link-layer frame via interface 223.1.2.9 • Router[DLL] must know the MAC address of 223.1.2.2 IPDG arrives at 223.1.2.2 E[DLL] recognizes A[MAC] and sends IPDG up to E[IP]
Dest. next network router Nhops interface 223.1.1 223.1.2 223.1.3
-
1 1 1
223.1.1.1
223.1.3.27
223.1.2.1
A 223.1.1.2 223.1.1.4
B
223.1.1.4 223.1.2.9
223.1.2.9
223.1.2.2 223.1.1.3
E
223.1.3.27
223.1.3.2
223.1.3.1
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Versi: 1.1
Subnetting Add another level to address/routing hierarchy: subnet Subnet masks define variable partition of host part Subnets visible to routers only within site Original 1 0 Address Subnetted 1 0 Address
Net ID
Host ID Figure 8.6
Subnet ID
Net ID Network number
Host ID
Host number
Class B address 111111111111111111111111 00000000 Subnet mask (255.255.255.0) Network number 12
Subnet ID
Subnetted address
Host ID Versi: 1.1
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Subnet Example Subnet mask: 255.255.255.128 Subnet number: 128.96.34.0 128.96.34.15
128.96.34.1
H1 R1
Subnet mask: 255.255.255.128 Subnet number: 128.96.34.128
128.96.34.130
128.96.34.139
128.96.34.129
H2 R2
H3 128.96.33.14
128.96.33.1
Subnet mask: 255.255.255.0 Subnet number: 128.96.33.0
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Forwarding table at router R1 Subnet Number Subnet Mask 128.96.34.0 255.255.255.128 128.96.34.128 255.255.255.128 128.96.33.0 255.255.255.0
Next Hop interface 0 interface 1 R2
Versi: 1.1
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