Transcript 20071230102313k5

ITEC4610
Network Switching and Routing
ดร. ประวิทย์ ชุมชู
หัวหน้าสาขาวิชาวิศวกรรมสารสนเทศและการสื่ อสาร(ICE)
MUT
Email: [email protected]
ห้องทางาน: F402
เบอร์โทรศัพท์ที่ทางาน: (02)9883655 ต่อ 220
เบอร์โทรศัพท์เคลื่อนที่: 065343850
MUT
Class VI
EIGRP (Enhanced Internal Gateway Routing Protocol)
ดร. ประวิทย์ ชุมชู
หัวหน้าสาขาวิชาวิศวกรรมสารสนเทศและการสื่ อสาร(ICE)
MUT
Email: [email protected]
ห้องทางาน: F402
เบอร์โทรศัพท์ที่ทางาน: (02)9883655 ต่อ 220
เบอร์โทรศัพท์เคลื่อนที่: 065343850
MUT
Outlines
กล่าวนาการทางานของ EIGRP
การทางาน EIGRP (Enhanced Internal Gateway Routing Protocol)
Neighbor discovery and Recovery
หลักการทางานของ DUAL
Reliable Transport Protocol (RTP)
PDM (Protocol-dependent Module)
ประเภทของแพ็คเก็ตที่ใช้ในการสื่ อสารระหว่างเร้าเตอร์ของ EIGRP
ตัวอย่างการสร้าง routing table ของ EIGRP
Summary
MUT
Routing Algorithms
• Distance vector routing ถูกใช้ใน RIPv1 RIPv2 IGRP
• Link-state Routing ถูกใช้ใน OSPF
• Advanced distance-vector ถูกใช้ใน EIGRP
– Dual (Diffusing Update Algorithm)
MUT
Distance vector routing
• Initialization
– เริ่ มต้นสร้าง routing table
• Sharing
– การแลกเปลี่ยน routing table
• Updating
– การแก้ไข routing table
• คานวณเส้นทางโดยใช้
– Bellman-ford’s algorithm
MUT
Link-State routing
•
•
•
•
เริ่ มต้นตรวจสอบสถานะของลิงค์
แต่ละโหนดเก็บ link states ของตัวเอง
กระจาย link states ให้โหนดอื่นภายในพื่นที่ (flooding)
คานวน shortest path ของจากโหนดตัวเองไปยังโหนดอื่น ๆ โดยใช้
– Dijktsta ‘a algorithm
MUT
เปรี ยบเทียบ Distance-vector และ Link state
• ข้อดี
– ใช้หน่วยความจาน้อย
– การคานวณไม่ซบั ซ้อน
• ข้อเสี ย
– Slow convergence
– สามารถเกิด routing loop
MUT
• ข้อดี
– Fast convergence
• ข้อเสี ย
– ใช้หน่วยความจามาก
– การคานวณซับซ้อนกว่า
ตัวอย่างการทางานของ RIP
Node 2
Node 3
Node 1
Link 1-5
Node 5
Node 4
Network A
Node 2 ’s routing Table
Dst
A
...
MUT
Next-hop
Node 1
...
Cost
2
...
ถ้า link 1-5 มีปัญหา
Node 2
Node 3
Node 1
Link 1-5
Node 5
Node 4
Network A
• Node 2 ไม่สามารถส่ งข้อมูลไปยัง Network A
• รอจนเกิด timeout (90 second)
• ใช้เวลาประมาณ 90-120 วินาทีในการที่จะได้เส้นทางใหม่ไปยัง
ไปยัง network A โดยผ่านเร้าเตอร์ 3
MUT
EIGRP
•
•
•
•
•
•
•
•
•
•
Improved version of IGRP
Backwards compatible with IGRP
Improved convergence
Sends updates like a link state routing protocol
Supports VLSM/CIDR
Supports many layer 3 routed protocols (not just IP)
Routing protocol designed by Cisco
Combines best features of link-state and distance vector routing protocols
Compatible with IGRP
Two major versions
– Version 0
– Version 1
MUT
Outlines
กล่าวนาการทางานของ EIGRP
การทางาน EIGRP (Enhanced Internal Gateway Routing Protocol)
Neighbor discovery and Recovery
หลักการทางานของ DUAL
Reliable Transport Protocol (RTP)
PDM (Protocol-dependent Module)
ประเภทของแพ็คเก็ตที่ใช้ในการสื่ อสารระหว่างเร้าเตอร์ของ EIGRP
ตัวอย่างการสร้าง routing table ของ EIGRP
Summary
MUT
EIGRP Protocol
• Using DUAL
• Neighbor Discovery and mechanisms
• Reliable transport mechanism used to exchange update messages
among routers that guarantee ordered delivery
• Protocol dependent modules that enable its operation in a multipleprotocol environments such as IPX, IP, Apple talk
MUT
Five Types of EIGRP Packets
• Hello packets (H)
– Link Discovery
• Update packets (U)
– Update when a link change
• ACK packets (A)
– ACK for Update message
• Query packets (Q)
– Query Status of networks
• Reply packets (R)
– Reply to Query Messages
MUT
Outlines
กล่าวนาการทางานของ EIGRP
การทางาน EIGRP (Enhanced Internal Gateway Routing Protocol)
Neighbor discovery and Recovery
หลักการทางานของ DUAL
Reliable Transport Protocol (RTP)
PDM (Protocol-dependent Module)
ประเภทของแพ็คเก็ตที่ใช้ในการสื่ อสารระหว่างเร้าเตอร์ของ EIGRP
ตัวอย่างการสร้าง routing table ของ EIGRP
Summary
MUT
Neighbor Discovery and mechanisms
• Link (neighbor) discovery and dead detection is used in determining when links
appear and disappear
• Small Hello messages are sent periodically
– The hold time used to set a timer for duration of link up state after receiving hell message
– Factors used in the metric computation
• A link is discovery when the first hello packets is received (link up state)
– A request is made of DUAL to send a full update to the link
• A link down state occurs when
– Hold down timer expires
– Interface going down
– A maximum retransmission threshold exceeded
MUT
Hello interval
• 5-second hello:
– Broadcast media, such as Ethernet, Token Ring and FDDI
– Point-to-point links, such as PPP or HDLC leased circuits, Frame Relay point-to-point
subinterfaces, and ATM
– High bandwidth (greater than T1) multipoint circuit such as ISDN PRI and Frame Relay
• 60-second hello:
– Multipoint circuits T1 bandwidth or slower, such as Frame Relay multipoint interfaces,
ATM multipoint interfaces
– Switched virtual circuits and ISDN BRIs
MUT
Example of Hello packets
A
B
I am router A, Who is on the link?
Hello Message
Topology table
Here is my routing information.
Update Message
Thank for the information.
Here is my routing information.
Ack Message
Thanks for the information.
Converged
MUT
Ack Message
Update Message
Example of Hello packets
A
B
I am router A, Who is on the link?
Hello Message
Hold Time =15 (Link Up)
I am router A, Who is on the link?
5s
I am router A, Who is on the link?
Hello Message
Hold Time =15 (Link Up)
Hello Message
Hold Time =15 (Link Up)
5s
I am router A, Who is on the link?
Hello Message
Hold Time =15 (Link Up)
5s
I am router A, Who is on the
link?
5s
I am router A, Who is on the link?
5s
I am router A, Who is on the
link?
5s
I am router A, Who is on the link?
5s
I am router A, Who is on the
link?
MUT
Hello Message
Hold Time =0 (Link DOWN)
5s
5s
I am router A, Who is on the link?
Hello Message
Hold Time =0 (Link DOWN)
Neighbor Table
• Neighbor table contains information about router’s neighbors
including:
–
–
–
–
–
–
–
MUT
Neighbor address and interface
Hold time and Uptime
Smooth round trip timer (SRTT)
Retransmission timeout (RTO)
Handle (H)
Queue count
Sequence number
ตัวอย่าง
The hold time=15 or 180 sec
Hold = 10-15 sec, Hello interval =5 sec
Hold = 120-180 sec, Hello interval =60 sec
MUT
Outlines
กล่าวนาการทางานของ EIGRP
การทางาน EIGRP (Enhanced Internal Gateway Routing Protocol)
Neighbor discovery and Recovery
หลักการทางานของ DUAL
Reliable Transport Protocol (RTP)
PDM (Protocol-dependent Module)
ประเภทของแพ็คเก็ตที่ใช้ในการสื่ อสารระหว่างเร้าเตอร์ของ EIGRP
ตัวอย่างการสร้าง routing table ของ EIGRP
Summary
MUT
หลักการทางานของ DUAL
(Diffusing Update Algorithm)
• Topology Table
• ต่างจาก LS
• ไม่มีใน DV
• Neighbor Table
• ไม่มีใน LS & DV
• Routing Table
เหมือนกับ LS & DV
MUT
DUAL quires its neighbors who, in turn, may
query their neighbors and so forth….
Dual
•
•
•
•
•
•
MUT
Advance Distance Vector
Compute shortest path distributedly
No Routing Loop
No Counting-to-Infinity behavior
Performance better than DV
Performance similar to the performance of LS
Route States (two states)
•
•
•
•
•
Active - recomputation is being performed
Passive - no recomputation going on
If feasible successors are always available, a destination never goes into the active state.
Recomputation occurs when no feasible successor route exists
If a neighbor who is the only feasible successor to a destination goes down, all of the neighbor's
routes enter the active state and trigger route recomputation.
• Recomputation Process
– Send a query packet to all neighboring routers
– Neighbor sends
• a reply that it has a feasible successor, or
• a query packet to indicate it is partcipating in the recomputation
MUT
– Routes in the active state cannot have their routing table information changed
– Once all neighbors have replied the topology table entry for the destination returns to the passive state and
the router may then select a feasible successor.
Topology table
DN=Destination Network
C=Cost
RD=Report Distance
RD=Feasible Distance
Topology Table(B)
DN
N2
N2
N3
N3
N4
N4
N5
N5
via
-A
-C
C
A
A
C
C
2
17
5
17
12
15
7
14
RD
12
15
10
10
2
12
FD
2
5
12
7
-
B
N
o
etw
N3
rk
Co
A
Ne
two
Cost=2
Network N5
DUAL STATE for 172.16.100.0/24
MUT
Next hop
FD
Cost
RD
Co
st=
st=
Network N2
rk
N
10
Cost=2
5
4
C
Report Distance (RD)
• The cost to reach the destination N form router A
Topology Table(B)
DN
N2
N2
N3
N3
N4
N4
N5
N5
MUT
via
-A
-C
C
A
A
C
C
2
17
5
17
12
15
7
14
RD
12
15
10
10
2
12
B
N
o
etw
Co
A
FD
2
5
12
7
-
N3
rk
Ne
two
Cost=2
Network N5
• For example
• A reports B: the cost to reach the destination N2
form router A is 12 (10+2)
Co
st=
Network N2
Cost=2
5
st=
rk
N
10
4
C
Feasible Distance (FD) and successor
• The lowest cost to reach a destination is FD
• The next hop router in the lowest cost path to the destination is referred to as
the successor
Topology Table(B)
DN
N2
N2
N3
N3
N4
N4
N5
N5
MUT
via
-A
-C
C
A
A
C
C
2
17
5
17
12
15
7
14
RD
12
15
10
10
2
12
FD
2
5
12
7
-
B
N
o
etw
N3
rk
Co
A
Ne
two
Cost=2
Network N5
Co
st=
Network N2
Cost=2
5
st=
rk
N
4
10
• For example
• To reach N4, there are 2 paths: via C and A. The lowest cost is
12 via C, therefore FD =12, successor is router C
C
Feasible Successors (FS)
•
•
•
•
Feasible successor is next best route to destination
EIGRP may keep more than one feasible successor in its topology table
Next hop router must have reported distance (RD) to destination less than feasible distance of route
of current successor
B
Helps prevent routing loops
Topology Table(B)
DN
N2
N2
N3
N3
N4
N4
N5
N5
MUT
via
-A
-C
C
A
A
C
C
2
17
5
17
12
15
7
14
RD
12
15
10
10
2
12
FD
2
5
12
7
-
• For example (router B)
• FS of N2=NULL, FS of N3=NULL, FS of N4=A
• FS of N5=NULL
N
o
etw
N3
rk
Co
A
Ne
two
Cost=2
Network N5
Co
st=
Network N2
Cost=2
5
st=
rk
N
10
4
C
Building the Topology Table with Update Packets
• Topology table consists of all the routes each neighbor advertises
– Includes metrics advertised by neighbors for routes
– Includes metric the router itself uses to forward packets to those destinations
• Adds metric to get to neighbor to metric advertised by neighbor to destinations
MUT
Building and Maintaining Routing Tables
• Building routing tables for first time
– When router becomes part of EIGRP network, it sends out hello packets on
all interfaces
– Neighbor replies with update packets containing Init bit to indicate a new
neighbor relationship.
– New router acknowledges each update packet and uses information in
packets to builds its topology table
– New router then sends update packets to all neighbors
– Each neighbor replies with an ACK
– See the Table in the next slide
MUT
Building a Routing Table for the First Time
1.
2.
3.
4.
5.
6.
MUT
The new router sends packets hello packets out all of interfaces
A neighbor replies with a series of update packets
The new router sends an ACK packet for each update packet
received
The new router builds its topology table with the information
contained in the update packets
The new router sends update packets to all of its neighbors
Each neighbor replied with an ACK packet for each update packet it
receives
Examples of Building a Routing Table for the First Time
B
N
o
etw
N3
rk
Co
A
Ne
two
Cost=2
Co
Network N5
A
st=
st=
Network N2
Cost=2
5
rk
N
4
C
10
B(new router)
H
H
Topology Table(A)
DN
N2
N4
N5
via
C
---
C
12
10
2
RD
2
-
FD
-10
2
C
U
Topology Table(C)
U
A
A
Topology Table(B)
MUT
DN
N2
N2
N3
N3
N4
N4
N5
N5
via
-A
-C
C
A
A
C
C
2
17
5
17
12
15
7
14
RD
12
15
10
10
2
12
FD
2
5
12
7
-
DN
N2
N4
N5
via
--A
C
2
10
12
RD
2
FD
2
10
-
Examples of Building a Routing Table for the First Time (cont.)
B
N
ork
etw
N3
Co
A
Ne
two
Cost=2
Co
Network N5
st=
Network N2
Cost=2
5
st=
rk
N4
C
10
Topology Table(B)
DN
N2
N2
N3
N3
N4
N4
N5
N5
A
U
Topology Table(A)
DN
N2
N2
N3
N3
N4
N4
N5
MUT
via
B
C
-C
-B
--
C
7
12
5
17
10
17
2
RD
2
2
7
12
-
FD
7
-5
-10
-2
via
-A
-C
C
A
A
C
C
2
17
5
17
12
15
7
14
RD
12
15
10
10
2
12
B(new router)
FD
2
5
12
7
-
C
U
A
U
A
U
A
A
----------Converged--------------
Topology Table(C)
DN
N2
N2
N3
N3
N4
N4
N5
N5
via
-A
B
A
-B
B
A
C
2
17
7
15
10
17
9
12
RD
7
5
5
15
7
2
FD
2
7
10
9
-
Failure of the Primary Route
• DUAL algorithm looks at each feasible successor in topology database
– Chooses one with lowest metric; does not have to recalculate it
• If no feasible successor exists, router queries neighbors in query range
with split horizon rule to find new route
– New route goes from passive to active state and must be recalculated
• If no response to query packet within time limit, router enters stuck-inactive (SIA) state
MUT
Topology Change on an EIGRP Network
• When router joins network, it builds routing table, using information
from neighbors.
• If more than one possible path exists to a network, router chooses path
with best feasible distances
• If serial link goes down, router must find a new route to destination
network
MUT
Convergence in DUAL—local computation
B
Topology Table(A)
DN
N2
N2
N3
N3
N4
N4
N5
via
B
C
-C
-B
--
C
7
12
5
17
10
17
2
DN
N2
N3
N4
N5
via
B
----
C
7
5
10
2
RD
2
2
7
12
-
Routing Table(A)
Topology Table(A)
via
B
C
-C
-B
--
C
7
12
5
17
10
17
2
Routing Table(A)
MUT
DN
N2
N3
N4
N5
via
C
----
C
12
5
10
2
RD
2
2
7
12
-
FD
7
-5
-10
-2
FD
7
-5
-10
-2
ork
N3
Co
A
Ne
Network N5
B
U
A
Router A attempts to find a new successor for N2
The feasible successor is C. For the link
RD(=2)<FD(=7), So the C becomes new seccsor
Co
st=
Network N2
Cost=2
5
st=
two
Cost=2
A
Link A-B down Found
DN
N2
N2
N3
N3
N4
N4
N5
tw
Ne
rk
N4
C
10
C
Convergence in DUAL—Diffusing computation
B
Ne
two
DN
N2
N2
N3
N3
N4
N4
N5
N5
A
via
-A
-C
C
A
A
C
Routing Table(B)
DN
N2
N3
N4
N5
via
--C
A
Topology Table(A)
DN
N2
N2
N3
N3
N4
N4
N5
via
B
C
-C
-B
--
C
7
12
5
17
10
17
2
RD
2
2
7
12
-
FD
7
-5
-10
-2
C
2
17
5
17
12
15
7
14
Q
R
C
2
5
12
7
RD
12
15
10
10
2
12
Topology Table(C)
FD
2
5
12
7
-
DN
N2
N2
N3
N3
N4
N4
N5
N5
B
C
Link A-B down Found
Q
R
Routing Table(A)
DN
N2
N3
N4
N5
MUT
via
C
----
C
12
5
10
2
via
-A
B
A
-B
B
A
Router B attempts to find a new successor for N5
The feasible successor is C. For the link RD(=12)>FD(=7),
therefore C could not be a new successor. B needs to send query
to its Neighbors
C
2
17
7
15
10
17
9
12
Ne
RD
7
5
5
15
7
2
FD
2
7
10
9
-
Routing Table(C)
DN
N2
N3
N4
N5
via
-B
-B
C
2
7
10
9
Co
Network N2
st=
Cost=2
t=5
two
Cost=2
Network N5
3
s
Co
A
Topology Table(B)
N
rk
rk
N4
10
C
Outlines
กล่าวนาการทางานของ EIGRP
การทางาน EIGRP (Enhanced Internal Gateway Routing Protocol)
Neighbor discovery and Recovery
หลักการทางานของ DUAL
Reliable Transport Protocol (RTP)
PDM (Protocol-dependent Module)
ประเภทของแพ็คเก็ตที่ใช้ในการสื่ อสารระหว่างเร้าเตอร์ของ EIGRP
ตัวอย่างการสร้าง routing table ของ EIGRP
Summary
MUT
Transport Mechanism
• Reliably
– A mix of multicasts and unicasts
• Multicast for first transmission, others using unicast
– Sequence number for Acknowledging
– A window size of one
– Update message (multicast), query message (multicast), reply message
(unicast)
– Estimation of smooth round trip time (SRTT)
– The retransmission timeout (RTO) is the time that the router will wait for an
acknowledgement before retransmitting the packet
MUT
Transport Mechanism (cont.)
• Unreliably
– Acknowledgement packets
– Hello packets
• For IP
– Protocol field is 88
– IP multicast address if 224.0.0.10
MUT
Example for Retransmission
RTO?
MUT
Outlines
กล่าวนาการทางานของ EIGRP
การทางาน EIGRP (Enhanced Internal Gateway Routing Protocol)
Neighbor discovery and Recovery
หลักการทางานของ DUAL
Reliable Transport Protocol (RTP)
PDM (Protocol-dependent Module)
ประเภทของแพ็คเก็ตที่ใช้ในการสื่ อสารระหว่างเร้าเตอร์ของ EIGRP
ตัวอย่างการสร้าง routing table ของ EIGRP
Summary
MUT
Protocol Dependent Modules (PDM)
• Response for initialization, building and decoding packets
• Interfacing DUAL to the routing table
• Proving protocol-dependent support routines for DUAL
IPX
IP
Apple Talk
PDM
Diffusing Update algorithm
Neighbor Discovery/Rcovery
Reliable Transport Protocol
IPX
MUT
IP
Apple talk
Network Layer
EIGRP Metric
• Five variables used to calculate metric
–
–
–
–
–
Bandwidth
Delay
Reliability
Load
Maximum transmission units (MTU)
• Uses constants, called K-values, to calculate final metric
• Final metric value multiplied by 256 results in a 32-bit metric value
MUT
Default K-values
bandwidth (kbps)
MUT
Delay (tens of microsecond)
ตัวอย่างการคานวณ Metric
Node 4
B=56
d=2000
Node 2
B=128
d=1000
Network A
Node 1
Node 3
B=10000
d=100
B=10000
d=100
B= bandwidth (kbps)
d= Delay (tens of microsecond)
MUT
ตัวอย่างการคานวณ metric
•
•
•
•
•
Metric=[K1*bandwidth+(K2*bandwidth)/(256-load)+K3*delay)]*[K5/(Reliability+K4)]
K1=1, K2=0, K3=1, K4=0, K5=0
Metric =[bandwidth + delay]
No floating point, Round down
Router 1 to Network A
– Via router 4
• (10,000,000/56+2200)*256=(180771+2200)*256=46277376
– Via router 3
• (10,000,000/128+1200)*256=(78125+1200)*256=79325*256=20307200
• Router 1 to Network A: Via router 3
MUT
Outlines
กล่าวนาการทางานของ EIGRP
การทางาน EIGRP (Enhanced Internal Gateway Routing Protocol)
Neighbor discovery and Recovery
หลักการทางานของ DUAL
Reliable Transport Protocol (RTP)
PDM (Protocol-dependent Module)
ประเภทของแพ็คเก็ตที่ใช้ในการสื่ อสารระหว่างเร้าเตอร์ของ EIGRP
ตัวอย่างการสร้าง routing table ของ EIGRP
Summary
MUT
Five Types of EIGRP Packets
•
Hello packet
– Hello packets assist in the discovery of EIGRP neighbors. The packets are multicast to 224.0.0.10.
•
Update packets
– Update packets contain the routing information of destinations. Update packets are unicast to newly discovered
neighbors; otherwise, update packets are multicast to 224.0.0.10 when a link metric changes. Update packets are
acknowledged to ensure reliable transmission.
•
ACK packets
– An acknowledgment packet acknowledges the reception of an update packet. An acknowledgment packet is a hello
packet with no data. Acknowledgment packets are sent to the unicast address of the sender of the update packet.
•
Query packets
– Query packets are sent to find feasible successors to a destination. Query packets are always multicast.
•
Reply packets
– Reply packets are sent to respond to query packets.
• Reply packets provide a feasible successor to the sender of the query.
• Reply packets are unicast to the sender of the query packet.
MUT
EIGRP packets
• The destination IP address in EIGRP depends on the packet type--some
packets are sent as multicast (with an address of 224.0.0.10) and others
are sent as unicast
• The source IP address is the IP address of the interface from which the
packet is issued.
• Following the IP header is an EIGRP header.
MUT
An EIGRP header
Opcode
1 Update
2 Reserve
3 Query
4 Reply
5 Hello
EIGRP process version
Used by the Reliable
Transport Protocol
Type Field Value field
0x0001 EIGRP parameters
(Hello/Hold-time)
0x0102 IP internal route
0x0103 IP External route
0
7
15
31
Version Opcode
Checksum
Flags
Sequence Number
Acknowledgement number
Autonomous system number
Type Field
Length
Value Field
Type Field
Length
Value Field
Other TLV triplets..
First bit is the init bit (used in new neighbor
relationship)
Second bit is the conditional receive bit (used in the
proprietary reliable multicast algorithm)
Other bits are not used
Type-Length-Value(TLV)
Type-Length-Value(TLV)
The fields following the EIGRP header depend on the Opcode field.
ACK - the 32-bit sequence last heard from the neighbor. A Hello
packet with a non-zero value is an ACK
MUT
General TLV
0
7
K1
K5
MUT
15
K2
reserved
23
31
K4
K3
Hold time
IP internal route updates
0
Reliability
Prefix length
7
15
Next hop
Delay
B/W
MTU
Load
23
31
Hop count
Reserverd
Destination
Type 0x0102
Length - Length of the TLV
Next Hop - The next hop route for this route
Delay - The number of 10 microsecond chunks which is the sum of delays
Bandwidth - 256 * IGRP bandwidth
MTU - The smallest MTU encountered along the route to this particular destination
network.
Hop Count - A number between 0x00 (directly connected network) and 0xFF.
Reliability - A number between 0x01 and 0xFF to indicate the error rates totalled along
the route. 0xFF is reliable.
Load - A number between 0x01 and 0xFF expressing the total load along a route where
0xFF is totally loaded.
Reserved - 0x0000 and not used.
MUT
Prefix Length - The number of bits used for the mask
Destination - Destination network
IP external route updates
0
7
15
23
31
Next hop
Originating router
Originating autonomous system
Arbitrary tag
Such as RIP
or OSPF metric
reserved
External protocol metric
External
Protocol ID
Delay
Flags
B/W
MTU
Reliability
Prefix length
MUT
Load
Hop count
Reserverd
Destination
ID of external routing Protocol
0x00 IGRP
0x02 EIGRP
0x04 RIP
0x06 OSPF
0x09 BGP
•
•
•
•
•
•
•
•
MUT
IP
external
route
updates(cont.)
Type 0x0103
Length - Length of the TLV
Next Hop - The next hop route for this route
Originating Autonomous System - The AS from where the route came
Tag - Used with Route Maps to track routes
External Protocol Metric - The metric for this route used by the external routing protocol e.g. IGRP, OSPF, RIP
Reserved - 0x0000 and not used.
External Protocol ID - identifies the external protocol advertising this particular route
–
–
–
–
–
–
–
–
–
–
–
0x01 - IGRP
0x02 - EIGRP (a different AS)
0x03 - Static Route
0x04 - RIP
0x05 - Hello
0x06 - OSPF
0x07 - IS-IS
0x08 - EGP
0x09 - BGP
0x0A - IDRP
0x0B - directly connected
IP external route updates(cont.)
•
•
•
•
•
•
•
•
•
•
MUT
Flags - 0x01 means the route is an external route whereas 0x02 means that the route could be a default route.
Delay - The number of 10 microsecond chunks which is the sum of delays
Bandwidth - 256 * IGRP bandwidth
MTU - The smallest MTU encountered along the route to this particular destination network.
Hop Count - A number between 0x00 (directly connected network) and 0xFF.
Reliability - A number between 0x01 and 0xFF to indicate the error rates totalled along the route. 0xFF is reliable.
Load - A number between 0x01 and 0xFF expressing the total load along a route where 0xFF is totally loaded.
Reserved - 0x0000 and not used.
Prefix Length - The number of bits used for the mask
Destination - Destination network
Outlines
กล่าวนาการทางานของ EIGRP
การทางาน EIGRP (Enhanced Internal Gateway Routing Protocol)
Neighbor discovery and Recovery
หลักการทางานของ DUAL
Reliable Transport Protocol (RTP)
PDM (Protocol-dependent Module)
ประเภทของแพ็คเก็ตที่ใช้ในการสื่ อสารระหว่างเร้าเตอร์ของ EIGRP
ตัวอย่างการสร้าง routing table ของ EIGRP
Summary
MUT
จงแสดงการสร้าง routing table ของ EIGRP
B
Network N3
A
2
N
ork
tw
e
N
Ne
two
rk
B=128
d=1000
N4
D
C
B=10000
d=100
MUT
Network N1
B=56
d=2000
B=10000
d=100
Metric
B
Network N3
A
2
N
ork
tw
e
N
Ne
two
rk
B=128
d=1000
N4
D
C
B=10000
d=100
MUT
Network N1
B=56
d=2000
B=10000
d=100
Topology Table
B=56
d=2000
A
rk
two
Ne
Ne
two
Topology Table(A)
DN
N1
N1
N2
N2
N3
N3
N4
MUT
N4
via
C
RD
FD
N2
rk
N
B=128
d=1000
Network N3
4
D
C
B=10000
d=100
Network N1
B
B=10000
d=100
Neighbor table
B
rk
two
A
Ne
Ne
two
N2
rk
N
B=128
d=1000
Network N3
4
D
C
B=10000
d=100
Neighbor Table(A)
H
0
1
MUT
Address
interface
Hold Up time
SRTT
RTO
Q Cnt
Seq num
Network N1
B=56
d=2000
B=10000
d=100
Routing Table
B=56
d=2000
rk
two
A
Ne
Ne
two
N2
rk
N
B=128
d=1000
Network N3
4
D
C
B=10000
d=100
Routing Table(A)
DN
N1
N2
N3
N4
MUT
via
C
Network N1
B
B=10000
d=100
Outlines
กล่าวนาการทางานของ EIGRP
การทางาน EIGRP (Enhanced Internal Gateway Routing Protocol)
Neighbor discovery and Recovery
หลักการทางานของ DUAL
Reliable Transport Protocol (RTP)
PDM (Protocol-dependent Module)
ประเภทของแพ็คเก็ตที่ใช้ในการสื่ อสารระหว่างเร้าเตอร์ของ EIGRP
ตัวอย่างการสร้าง routing table ของ EIGRP
Summary
MUT
Summary
MUT
Disadvantages of EIGRP
• Proprietary to CISCO
• Routers from other vendors cannot use or understand EIGRP
MUT
Refs
• “IP Routing”, Ravi Malhotra, First Edition January 2002
• Cisco CCNA3
• R. Albrightson, J. J. Garicia-Unal-Aceves, and J. Boyle, “EIGRP-A
fast Protocol Based on Distance Vector” In proc. Netwokr/Interop 94,
Las vegas, Nevada, June, 1998
• “EIGRP White papers” Cisco system
MUT