3Com Router User Manual

Routing Management Strategy407
Figure 143   Routing table illustration
3Com routers support not only static route configuration, but also dynamic 
routing protocols such as RIP, OSPF and BGP. Depending on the interface status 
and user configuration, a router can automatically obtain some direct routes 
during their operation.
Routing Management 
Strategy3Com routers support both manual configuration of a static route to a specific 
destination and dynamic routing protocol configuration which finds the...

408CHAPTER 26: IP ROUTING PROTOCOL
Except for the direct route (Connected), the priority of each dynamic routing 
protocol can be manually configured according to specific requirements. In 
addition, each static route can have a different priority.
Support of the Route 
BackupA backup route allows a router to automatically select another route to transmit 
data packets when the line changes, and enhances the user network reliability. To 
implement route backup, you can set a different priority to the...

27
CONFIGURING STATIC ROUTES 
This chapter covers the following topics:
■Static Route Overview 
■Configuring a Static Route
■Displaying and Debugging the Routing Table
■Static Route Configuration Example 
■Troubleshooting a Static Route Configuration
Static Route Overview A static route is a special route that allows a router to transmit packets over one 
path to a specified destination. Proper setting and application of the static route 
can guarantee network security effectively and at the same time,...

410CHAPTER 27: CONFIGURING STATIC ROUTES 
Default routes are very useful in network. In a typical network with hundreds of 
routers, dynamic routing protocols may consume lots of bandwidth resource. 
Using default route means that you can replace high bandwidth links with 
adequate bandwidth links to meet the requirements of communication for a large 
number of subscribers.
Configuring a Static 
RouteConfiguring static and default routes involves tasks described in the following 
sections: 
■Configuring...

Displaying and Debugging the Routing Table411
IP address to the link layer address (such as dialer route ip, x.25 map ip or 
fr map ip commands, and so on). In this case, you cannot specify the 
transmitting interface for the static route and must configure the IP address of the 
next hop.
Actually, all the route items must mark the address of the next hop. According to 
the destination address of packets, an IP router searches for the matching route in 
the routing table. Only when the address of next...

412CHAPTER 27: CONFIGURING STATIC ROUTES 
Static Route 
Configuration 
Example By configuring a status route, any two hosts or routes can communicate with each 
other.
Figure 144   Example of static route configuration
To configure a static route:
1Configure the static route for RouterA:
[RouterA] ip route-static 1.1.4.0 255.255.255.0 1.1.6.2
[RouterA] ip route-static 1.1.5.0 255.255.255.0 1.1.2.2
2Configure the static routes for RouterB:
[RouterB] ip route-static 1.1.5.0 255.255.255.0 1.1.3.1
[RouterB]...

28
CONFIGURING RIP
This chapter covers the following topics:
■RIP Overview
■Configure RIP 
■Displaying and Debugging RIP 
■RIP - Unicast Configuration Example
■Troubleshooting RIP 
RIP OverviewThe Routing Information Protocol (RIP) is an interior gateway and dynamic routing 
protocol based on the Distance-Vector (D-V) routing algorithm. RIP uses User 
Datagram Protocol (UDP) packets to exchange routing information and adopts 
hop count to measure the distance from the destination, called the routing...

414CHAPTER 28: CONFIGURING RIP
The procedure of running RIP can be described as follows:
1When a specific router is starting RIP for the first time, it broadcasts request 
messages to the neighbor routers. After receiving the request messages, the 
neighbor routers respond to the request and return response messages including 
local routing information.
2After receiving the response message, the router modifies the local routing table 
and sends triggered modified messages to the neighboring routers by...

Configure RIP 415
■Configuring RIP Horizontal Segmentation on the Interface
■Configuring Route Import for RIP
■Specifying Default Route Metric Value for RIP
■Specifying Additional Route Metric Values for RIP
■Setting Route Preference
■Configuring Route Distribution for RIP
■Resetting RIP
Enabling RIPTo enter RIP view, you must first enable RIP, then configure the parameters related 
to the RIP protocol. Interface-related parameters are not subject to enabling of RIP. 
Perform the following configurations...

416CHAPTER 28: CONFIGURING RIP
Defining a Neighboring 
Route
r
RIP is a broadcast protocol. It exchanges routing information with 
non-broadcasting networks in unicast mode.
Perform the following configurations in RIP view.
Ta b l e 471   Define a Neighboring Router
By default, no neighboring routers are defined.
Normally, this command is not recommended because the node on the other end 
does not need to receive two identical packets at the same time. Also when a peer 
sends messages, it is also subject...