Unicast Routing
20-6
20
Configuring Network Interfaces for RIP
For each interface that participates in the RIP routing process, you must specify the
protocol message type accepted (i.e., RIP version) and the message type sent (i.e.,
RIP version or compatibility mode), the method for preventing loopback of protocol
messages, and whether or not authentication is used (i.e., authentication only
applies if RIPv2 messages are being sent or received).
Command Usage
Specifying Receive and Send Protocol Types
• Setting the RIP Receive Version or Send Version for an interface overrides the
global setting specified by the RIP / General Settings, Global RIP Version field.
• You can specify the Receive Version based on these options:
- Use “RIPv1” or “RIPv2” if all routers in the local network are based on RIPv1 or
RIPv2, respectively.
- Use “RIPv1 or RIPv2” if some routers in the local network are using RIPv2, but
there are still some older routers using RIPv1.
- Use “Do Not Receive” if you do not want to add any dynamic entries to the
routing table for an interface. (For example, you may only want to allow static
routes for a specific interface.)
• You can specify the Send Version based on these options:
- Use “RIPv1” or “RIPv2” if all routers in the local network are based on RIPv1 or
RIPv2, respectively.
- Use “RIPv1 Compatible” to propagate route information by broadcasting to other
routers on the network using the RIPv2 advertisement list, instead of
multicasting as normally required by RIPv2. (Using this mode allows RIPv1
routers to receive these protocol messages, but still allows RIPv2 routers to
receive the additional information provided by RIPv2, including subnet mask,
next hop and authentication information.)
- Use “Do Not Send” to passively monitor route information advertised by other
routers attached to the network.
Loopback Prevention
Just as Layer 2 switches use the Spanning Tree Algorithm to prevent loops, routers
also use methods for preventing loops that would cause endless retransmission of
data traffic. When protocol packets are caught in a loop, links will be congested, and
protocol packets may be lost. However, the network will slowly converge to the new
state. RIP utilizes the following three methods that can provide faster convergence
when the network topology changes and prevent most loops from occurring:
• Split Horizon – Never propagate routes back to an interface port from which they
have been acquired.
• Poison Reverse – Propagate routes back to an interface from which they have
been acquired, but set the distance-vector metrics to infinity. (This provides faster
convergence.)
• Triggered Updates – Whenever a route gets changed, broadcast an update
message after waiting for a short random delay, but without waiting for the periodic
cycle.
Summary of Contents for 8926EM
Page 6: ...ii ...
Page 34: ...Getting Started ...
Page 44: ...Introduction 1 10 1 ...
Page 62: ...Initial Configuration 2 18 2 ...
Page 64: ...Switch Management ...
Page 76: ...Configuring the Switch 3 12 3 ...
Page 118: ...Basic Management Tasks 4 42 4 ...
Page 164: ...User Authentication 6 28 6 ...
Page 176: ...Access Control Lists 7 12 7 ...
Page 284: ...Quality of Service 14 8 14 ...
Page 294: ...Multicast Filtering 15 10 15 ...
Page 300: ...Domain Name Service 16 6 16 ...
Page 310: ...Dynamic Host Configuration Protocol 17 10 17 ...
Page 320: ...Configuring Router Redundancy 18 10 18 ...
Page 344: ...IP Routing 19 24 19 ...
Page 356: ...Unicast Routing 20 12 20 Web Click Routing Protocol RIP Statistics Figure 20 5 RIP Statistics ...
Page 386: ...Unicast Routing 20 42 20 ...
Page 388: ...Command Line Interface ...
Page 400: ...Overview of the Command Line Interface 21 12 21 ...
Page 466: ...SNMP Commands 24 16 24 ...
Page 520: ...Access Control List Commands 26 18 26 ...
Page 546: ...Rate Limit Commands 30 2 30 ...
Page 612: ...VLAN Commands 34 24 34 ...
Page 626: ...Class of Service Commands 35 14 35 ...
Page 670: ...DHCP Commands 39 16 39 ...
Page 716: ...IP Interface Commands 41 36 41 ...
Page 768: ...IP Routing Commands 42 52 42 ...
Page 770: ...Appendices ...
Page 791: ......