IGRP, Interior Gateway Routing Protocol, like RIP, it is a classful, distance_vector routing tool.
It is propietary of Cisco Router only.
192.168.1.0/24 192.168.2.0/24
Segment1 Segment2
| |
| |
| |
e0 e0
| |
R1 R2
\ /
* s0 * s1
192.168.3.0/24 \ / 192.168.4.0/24
Segment3 \ / Segment4
\ /
\ /
* s1 * s0
\ /
R3
|
to0
|
|
|
Segment5
192.168.5.0/24
|
|
|
to0 (token ring)
|
R4
|
e0
|
|
|
Segment6
192.168.6.0/24
the features of Routes:
-
Bandwidth
-
Total Delay
IGRP config for R1:
interface Ethernet0
ip addr 192.168.1.1 255.255.255.0
interface Serail0
ip addr 192.168.3."2" 255.255.255.0
router igrp
network 192.168.1.0
network 192.168.3.0
IGRP config for R2:
interface Ethernet0
ip addr 192.168.2.1 255.255.255.0
interface Serail1
ip addr 192.168.4.2 255.255.255.0
router igrp
network 192.168.2.0
network 192.168.4.0
IGRP config for R3:
interface S0
ip addr 192.168.4.1 255.255.255.0
interface S1
ip addr 192.168.3.1 255.255.255.0
interface TO0
ip addr 192.168.5.1 255.255.255.0
routing igrp 1
network 192.168.3.0
network 192.168.4.0
network 192.168.5.0
The Routing Table of R1:
R1$show ip route
C 192.168.1.0/24 is directly connected. E0
C 192.168.3.0/24 is directly connected. S0
I 192.168.2.0/24 [] via 192.168.3."1", S0
I 192.168.4.0/24 [] via 192.168.3."1", S0
I 192.168.5.0/24 [] via 192.168.3."1", S0
I 192.168.6.0/24 [] via 192.168.3."1", S0
R3$ debug ip igrp transactions
> IGRP protocol debugging is on
...
The IGRP info is encapsulated in the IP datagrams, the specific info includes header & route entries. This datagrams are destined fir the Local Braodcast Addr 255.255.255.255.
IGRP Routing Update Format is like this
+------------+---------+---------+------+
| version | Opcode | Edition | AS |
+------------+---------+---------+------+
| | Network |
| +----------------+---------+
| Subnet | | |
| |Exterior Network|checksum |
| | | |
+------------+----------------+---------+
| Route Entry for Subnet |
+---------------------------------------+
| Route Entry for Network |
+---------------------------------------+
| Route Entry for Exterior Network |
+---------------------------------------+
IGRP Route Entry Format is like this
+---------------------------------------+
| Destination |
+---------------------------------------+
| Delay |
+---------------------------------------+
| Bandwidth |
+---------------------------+-----------+
| Path MTU |reliability|
+------------+--------------+-----------+
| Load | Hop Count |
+------------+--------------------------+
Destination == Advertised Network Prefix
-
Subnet Route Entry
-
Network Route Entr
-
Exterior Network Route Entry,
A router can advertise 2 types of network prefixes via GRIP:
classful network addr
subnets of classful network addr || more interfaces whose IP addr belongs to these classful network addr.
The IGRP routers can not advertise the default addr 0.0.0.0, and individual host addr (for instance, 192.168.1.1/32).
Typically provides access to Internet, or another Network.The traffic sent to unknown destinations can be forwarded thru the exterior network.
The Router that advertises exterior networks can be used as the Default Router by the routers that accepts its routing updates.
(to be continued...)
https://github.com/QueenieCplusplus/BGP
-
IGMP
-
CGMP, Cisco Group Mgmt Protocol
-
PIM, Protocol Independent Multicast
(to be continued...)