![Page 1: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/1.jpg)
1
Lesson 5 Internet Protocol
Objectives :
Understanding connection-less type network architecture,
protocol and system. TCP-IP or Internet is typical connection-
less network. Basic protocols such as signaling and routing are
described.
![Page 2: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/2.jpg)
2Fig.4.1
IP header
HeaderLengthVersion TOS Length
Identification(13 bit)
Fragment offset
TTL Protocol Checksum
Source address
Destination address
(3 bit)Flag
(4 bit) (4 bit)
Structure of IP header
IP header is used for network layer function. Packet transmission is its function.
Destination and Source address are written on the header.
![Page 3: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/3.jpg)
3
IP address
11000001
11111111
Prefix
Mask
193.60.96.0/20193 60 96 0
255 255 240 0
prefix/mask length
255.255.255.255
D E
0.0.0.0
193.60.96.0/20193.60.0.0/16
00111100 01100000 00000000
11111111 11110000 00000000
0.0.0.0 255.255.255.255
A B C D E
Unicast
128 nets 16,384 nets 2,097,152 nets CIDR
Fig.4.2
IP address and CIDR
CIDR TECHNOLOGY → Multiple IP addresses are integrated into a single routing table.
1. The addresses share the same bits from the top of the IP address with the same bit pattern
(this is called a “prefix”).
2. The routing table 32-bit address and the 32-bit mask.
3. The routing protocol is expanded so that it can handle the 32-bit addresses and 32-bit
masks that have been introduced.
![Page 4: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/4.jpg)
4Fig.4.3
Prefix NHR
IP forwarding table
IP header
DA=148.32.96.4148.32.0.0/16148.32.96.0/24
140.252.13.0/24129.60.0.0/16
129.60. 225.0/24 EBA
AB
224.0.0.0/16 D
Concept of “Longest prefix matching” search and the forwarding table.
Using CIDR technology, routing table becomes small. Longest prefix matching is used for packet forwarding.
![Page 5: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/5.jpg)
5
Prefix/mask length Next hop Output port
129.66/16 129.30.166.55 3
129.66.103/24 129.30.167.13 4
176/8 129.30.168.20 6
176.10/16 129.30.169.21 5
176.10.25/24 129.30.170.169 1
Example of routing table
Table.7.2
![Page 6: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/6.jpg)
6Fig.7.24
b d
c e g
a
f
Prefixa: 00*b: 0001*c: 001*d: 0101*e: 101*f: 10100*g: 111*
0 1
0 1
0 1 0
1 1
0 1
0 1
0
1
0
1st bit
2nd bit
3rd bit
4th bit
5th bit
6th bit
101011
Trie structure
図5.4
![Page 7: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/7.jpg)
7Fig.7.25
fb c
a d e g
Prefixa: 00*b: 0001*c: 001*d: 0101*e: 101*f: 10100*g: 111*
0 1
0 101
01 1
01 11
00
Patricia tree
図5.5
![Page 8: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/8.jpg)
8Fig.7.26
100000
101000
101010
101011
101111
111111
10101*101*1*
101101Destination address
Step-1
Step-2
Step-3
Binary search method
![Page 9: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/9.jpg)
9Fig.7.27
Input dataOutput data(Result x)
Logic ciru
it
Entry
比較回路
比較回路
比較回路
比較回路
結果1
結果2
結果3
結果4
Reference data
Reference data
Reference data
Reference data
Comparison circuit
Comparison circuit
Comparison circuit
Comparison circuit
Result-1
Result-2
Result-3
Result-4
Typical structure of route lookup system using CAM
![Page 10: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/10.jpg)
10Fig.7.28
129.66/16
比較回路
129.66.103/24
比較回路
比較回路
比較回路
Priority en
coder
Destination IP address
(129.66.34.40)
Output port(3)
176.10.25/24
176/8
#1
#4
#3
#6
Prefix Mask length Output port
Mask len
gth
is descen
din
g ord
er
Comparison circuit
Comparison circuit
Comparison circuit
Comparison circuit
Ternary CAM (TCAM)
![Page 11: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/11.jpg)
11
Packet format using Ethernet header and TCP-IP header (Review)
Data
TCP header
IP header
Ethernet header
User data
Transport layer
Network layer
Data link layer
This lesson is focused on this part.
Fig.2.15
![Page 12: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/12.jpg)
12Fig.2.16
31161040
Code BitReserved
Urgent Pointer
Window
Option
DEST PORT (destination port number)
DATA
Checksum
HLEN(header length)
ACK (acknowledgment number)
SEQ (source sequence number)
SRC PORT (source port number)
TCPheader
FIN
SYN
RST
PSH
ACK
URG
Structure of TCP header (Review)
For rate control
Port number
TCP header is used for transport layer functions. Reliable transmission, flow control and error recovery are functions.
![Page 13: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/13.jpg)
13Fig.4.4
AS2
AS3EGP
IGPAS1
IGP and EGP(Inside-AS routing and Inter-AS routing)
Interior Gateway Protocol Exterior Gateway protocol
![Page 14: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/14.jpg)
14Table 4.1
Type Outline Example
Distance vector Seeks the next hop in the shortest route by exchanging a distance vector table (includes destination address information, etc). Bellman-Ford algorithm is used.
RIP, IGRP
Path vector Selects the route with the shortest path length that is possible to avoid a routing loop by exchanging a path vector (includes through node information to destination address, etc.)
BGP
Link state Each node has topology information by exchanging a link state and calculates the shortest route by using topology information.
OSPFIS-IS
Categorization and operation principle of routing protocol (Overview)
![Page 15: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/15.jpg)
15Fig.4.5
Distance vector type
5276
BC
AD
Distance
Next hopDestination
B
X C
A
Only next hop router and distance to the destination are listed.
D
![Page 16: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/16.jpg)
16Fig. 4.11
Destination=APath=D-B-A
E
F
A
B
D
C
Path vector type protocol
Set of destination and path is listed.
Path = D-B-A is the shortest path from F to A.
![Page 17: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/17.jpg)
17Fig. 4.15
A
32
1
1
3
5
4
1
B
Source
F
1
3
Link state type routing protocol
C
E
D
Distance information from source to all nodes are calculated. This “Map” is called “Link state”.
![Page 18: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/18.jpg)
18Table 4.2
Distance vector table (Distance vector type)
Destination Next hop Distance
129.60. 225.0/24148.32.0.0/16148.32.96.0/24224.0.0.0/16140.252.13.0/24129.60.0.0/16
EBADAB
3327
2910350
![Page 19: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/19.jpg)
19
Concept of operation of distance vector type routing protocol
50BA
Distance
Next hopDestination
52101
BC
AA
Distance
Next hopDestination
100CA
Distance
Next hopDestination
B
X C1
2
A
Select this
50
100
Only next hop router (NHR) and distance are known.
Fig.4.5
![Page 20: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/20.jpg)
20Fig.4.6
Bellman’s formula
i
j
D(t,i)
d(i,j)
D(t,j)
Destination
SourceD(t+1,i) = min(D(t,i), d(i,j)+D(t,j))
Shortest distance from source to destination can be determined by Bellman’s formula. It selects shorter path among alternative routes.
![Page 21: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/21.jpg)
21Fig.4.7
ABC
Src. Dst.A (0,A) (0,A) (0,A) (0,A) (0,A) (0,A) (0,A)B (1,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B)C (2,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B)A (1,A) (Inf,A) (3,C) (3,C) (5,C) (5,C) (7,C)B (0,B) (0,B) (0,B) (0,B) (0,B) (0,B) (0,B)C (1,C) (1,C) (1,C) (1,C) (1,C) (1,C) (1,C)A (2,B) (2,B) (2,B) (4,B) (4,B) (6,B) (6,B)B (1,B) (1,B) (1,B) (1,B) (1,B) (1,B) (1,B)C (0,C) (0,C) (0,C) (0,C) (0,C) (0,C) (0,C)
(dist,nh)
5 6Time 1 2 3 4
A
B
C
0Detect link down
Counting to Infinity problem
![Page 22: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/22.jpg)
22Fig. 4.8
ABC
Src. Dst.A (0,A) (0,A) (0,A) (0,A) (0,A) (0,A) (0,A)B (1,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B)C (2,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B)A (1,A) (Inf,A) (Inf,C) (Inf,C) (Inf,C) (Inf,C) (Inf,C)B (0,B) (0,B) (0,B) (0,B) (0,B) (0,B) (0,B)C (1,C) (1,C) (1,C) (1,C) (1,C) (1,C) (1,C)A (2,B) (2,B ) (2,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B)B (1,B) (1,B) (1,B) (1,B) (1,B) (1,B) (1,B)C (0,C) (0,C) (0,C) (0,C) (0,C) (0,C) (0,C)
(dist,nh)
A
B
C
0 5 6Time 1 2 3 4Detect link down
Poison-reverse
Split horizon/Poison reverse method
![Page 23: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/23.jpg)
23Fig. 4.9
Src. Dst.
A (0,A) (0,A) (0,A) (0,A) (0,A) (0,A) (0,A) (0,A) (0,A) (0,A)B (1,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B)C (2,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B)D (2,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B) (Inf,B)A (1,A) (Inf,A) (Inf,A) (Inf,A) (4,C) (4,C ) (4,C) (7,C) (7,C ) (7,C)B (0,B) (0,B) (0,B) (0,B) (0,B) (0,B) (0,B) (0,B) (0,B) (0,B)C (1,C) (1,C) (1,C) (1,C) (1,C) (1,C) (1,C) (1,C) (1,C) (1,C)D (1,D) (1,C) (1,C) (1,C) (1,C) (1,C) (1,C) (1,C) (1,C) (1,C)A (2,B) (2,B) (3,D) (3,D) (3,D) (3,D) (6,D) (6,D) (6,D) (9,D)B (1,B) (1,B) (1,B) (1,B) (1,B) (1,B) (1,B) (1,B) (1,B) (1,B)C (0,C) (0,C) (0,C) (0,C) (0,C) (0,C) (0,C) (0,C) (0,C) (0,C)D (1,D) (1,C) (1,C) (1,C) (1,C) (1,C) (1,C) (1,C) (1,C) (1,C)A (2,B) (2,B) (2,B) (Inf,B) (Inf,B) (5,B) (5,B ) (5,B) (8,B) (8,B)B (1,B) (1,B) (1,B) (1,B) (1,B) (1,B) (1,B) (1,B) (1,B) (1,B)C (1,C) (1,C) (1,C) (1,C) (1,C) (1,C) (1,C) (1,C) (1,C) (1,C)
D (0,D) (0,D) (0,D) (0,D) (0,D) (0,D) (0,D) (0,D) (0,D) (0,D)
(dist,nh)
A
C
D
0
B
5 9Time 1 2 3 4 6 87
ABC
D
Detect link down
Problem of Split horizon/Poison reverse
![Page 24: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/24.jpg)
24
Path vector type protocol
Destination=APath=D-B-A
Destination=APath=E-B-A
Destination=APath=E-C-A
E
F
A
B
D
C
Fig.4.11
![Page 25: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/25.jpg)
25Fig. 4.12
A
Link state L
Flooding
C E
A
B D
Concept of link state and “Flooding”
Link state information is flooding to all the nodes. Each link state table is updated by this flooding information.
![Page 26: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/26.jpg)
26Fig. 4.15
Link state type routing protocol
1
32
1 A
1
3
5
4
1
C
B
D
dji=1
2Dj
Destination node
Q
Calculates Dj=min(Dj,dij+Di) for node-j.Determines the group of nodes Q that Dj becomes minimum.Remove it from Q
A=1 determinedRest nodes: B,C,DB=min(3,1+1)=2 → this is the smallestC=min(4,5+1)=4D=min(3,2+1)=3B=2 determined
F
1
3
E
Shortest path is found by “Dijkustra’s algorithm”
![Page 27: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/27.jpg)
27Fig. 4.16
Example of advertising the link state
(b) Example of network LSA
D B
AC
A BLink state of router-B
A D CLink state of router-B
A BLink state of router-CB D C
Link state of router-A
D
B
A
C
Network aa
Link state of router-A
ABCD
(a) Example of router LSA
Abstracted information into one Network LSA.
![Page 28: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/28.jpg)
28
Flooding between areas
Fig. 4.17
C
E
A
B
D
C1 C2
C3 C4C5
C6
Area 0.0.0.2
Area 0.0.0.0 (Backbone)
Area 0.0.0.1
Summary-LSA by D- prefix = A- cost = min(C1+C3, C2+C5)
Summary-LSA by C- prefix = A- cost = C2
Summary-LSA by E- prefix = A- cost = min(C1+C4, C2+C6)
Summary-LSA by B- prefix = A- cost = C1
![Page 29: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/29.jpg)
29
Structure of LSA header
0 1 2 30 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| LS age | Options | LS type |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Link State ID |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Advertising Router |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| LS sequence number |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| LS checksum | length |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Elapsed time from LSA occurred (0~30 min)
Currently used when OSPF Hello Database Description Indicates LSA type (Note)
Independent numeric value
Sequential number
LSA header+container value(1~65535 byte)
LSA originatingrouter ID
LSA Type=1 Router LSAType=2 Network LSAType=3 Summary LSAType=4 ASBR Summary LSAType=5 AS-External LSA
Fig. 4.18
(Note)
![Page 30: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/30.jpg)
30
Structure of Router-LSA(Type-1, for routers connected by point-to-point)
0 1 2 30 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| LS age | Options | 1 |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Link State ID |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Advertising Router |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| LS sequence number |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| LS checksum | length |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| 0 |V|E|B| 0 | # links |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Link ID |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Link Data |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Type | # TOS | metric |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| |
... | |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Type | # TOS | TOS metric |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Link ID |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Link Data |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| ... |
Enter the same values
LS Type=1
LSA originating router’s ID
Number of links from router
Metrics(specified with 0~65535)
Link 1
Link i
Router TypeFor example,neighboring router’s ID
Link Type(Point-to-point,Transit, Stub, Virtual link)
FlagV: VirtualE: ASBRB: ABR
Fig. 4.19(Origin) Link1 (Destination)
![Page 31: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/31.jpg)
31
What is the metric?
Metric examples (0~65535)
1. Number of router hops (7hops)2. Distance (km)3. Number of wavelength (32 wavelength)4. Link bandwidth (1Gb/s)5. Bandwidth utilization (20%)6. Wavelength utilization / vacant number of
wavelength・・・
![Page 32: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/32.jpg)
32
Structure of Network-LSA
Fig. 4.20
0 1 2 30 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| LS age | Options | 2 |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Link State ID |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Advertising Router |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| LS sequence number |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| LS checksum | length |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Network Mask |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Attached Router |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| ... |
Enter value of DR(A)
Specify subnet mask
Enter all the routers within subnet
(A, B, C, D)
DR : Distinguished Router
ABCD
Networkα B C
DADR
![Page 33: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/33.jpg)
33
Summary-LSA from router-A to Arena X
Fig. 4.21
0 1 2 30 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| LS age | Options | 3 |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Link State ID |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Advertising Router |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| LS sequence number |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| LS checksum | length |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| Network Mask |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| 0 | metric |+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+| ... |
LS Type=3 : Summary LSA
ID of router-B
Metric(C1)
ID of router-A
Mask of Area A(0.0. 0.1)
TOS=0=normal service BSummary LSA
A
C1
Area0.0.0.1
![Page 34: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/34.jpg)
34
Concept of operation of BGP-4 (Path vector type protocol and loop detection)
Fig. 4.25
AS1
AS2AS3
10.1.1.1via AS4
10.1.1.1via AS3-AS4
10.1.1.1via AS1-AS3-AS4
10.1.1.1via AS2-AS1-AS3-AS4
IBGP
EBGP
AS4
![Page 35: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/35.jpg)
35
Border router (BGP speaker) and BGP session
Fig. 4.26
AS1
AS2 AS3
Border router
BGP session
EBGP
IBGP
:BGP speaker:Non BGP speaker
![Page 36: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/36.jpg)
36Fig. 4.32
Routing control of Outbound traffic using Local Pref attribute
R12R11
AS1
IBGP
AS4
AS2 AS3
128.213.0.0/16 128.213.0.0/16c
(Set local pref to 200)
(Set local pref to 300)
>128.213.0.0/16-- 300128.213.0.0/16-- 200
Select the route having a larger value of local pref
128.213.0.0/16
(AS1 to AS4 traffic control)
Select larger local pref value. It can create traffic control.
![Page 37: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/37.jpg)
37Fig. 4.33
R2
R12R11
MED = 120
MED = 200
128.213.0.0/16
AS2
AS1
Use smaller MED as a speaker
Routing control of Inbound traffic using MED attribute (AS2→AS1 access control)
Please use R11 for boarder
![Page 38: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/38.jpg)
38Fig. 4.36
EBGP
IBGPLearn routes
Don’t learn routes
IBGP is full meshed within AS
Never hops over multiple IBGP
Rule of advertising via IBGP session and EBGP session
In AS, each BGP router are connected with mesh topology.
![Page 39: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/39.jpg)
39Fig. 4.37
Scalability
EBGP
Full mesh2
)1( NN
IBGP mesh
![Page 40: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/40.jpg)
40Fig. 4.38
EBGPIBGP
AS1
AS2
AS3
RR
RR-Client
RR
RR-client
Route reflector
![Page 41: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/41.jpg)
41Fig. 4.39
Sub-AS10Sub-AS12
Sub-AS11
AS confederation 1
AS2
AS3
EBGP
EIBGP
IBGP
Confederation
The AS is divided into multiple SubAS, and each SubAS functions like a single AS.
![Page 42: 2017IBA lec5.ppt [互換モード] - Yamanaka Lab · 2017-09-25 · Priority encoder Destination IP address (129.66.34.40) Output port (3) 176.10.25/24 176/8 #1 #4 #3 #6 Prefix Mask](https://reader034.vdocuments.pub/reader034/viewer/2022050314/5f76d39c0a4e5d126535ba8c/html5/thumbnails/42.jpg)
42
Conclusions for Lesson 5
To understanding connection-less protocol,detail IP networking issues were studied. ICPIP packet structure and functions wereintroduced. Basic routing protocols were alsoshown in this session.