User manual

xStack DES-3800 Series Layer 3 Stackable Fast Ethernet Managed Switch
112
10 Update Response
11 Update Acknowledgement
RIP Command Codes
The field VERSION contains the protocol version number (1 in this case), and is used by the receiver
to verify which version of RIP the packet was sent.
RIP 1 Message
RIP is not limited to TCP/IP. Its address format can support up to 14 octets (when using IP, the
remaining 10 octets must be zeros). Other network protocol suites can be specified in the Family of
Source Network field (IP has a value of 2). This will determine how the address field is interpreted.
RIP specifies that the IP address, 0.0.0.0, denotes a default route.
The distances, measured in router hops are entered in the Distance to Source Network, and Distance to
Destination Network fields.
RIP 1 Route Interpretation
RIP was designed to be used with classed address schemes, and does not include an explicit subnet
mask. An extension to version 1 does allow routers to exchange subnetted addresses, but only if the
subnet mask used by the network is the same as the subnet mask used by the address. This means the
RIP version 1 cannot be used to propagate classless addresses.
Routers running RIP version 1 must send different update messages for each IP interface to which it is
connected. Interfaces that use the same subnet mask as the router’s network can contain subnetted
routes, other interfaces cannot. The router will then advertise only a single route to the network.
RIP Version 2 Extensions
RIP version 2 includes an explicit subnet mask entry, so RIP version 2 can be used to propagate
variable length subnet addresses or CIDR classless addresses. RIP version 2 also adds an explicit next
hop entry, which speeds convergence and helps prevent the formation of routing loops.
RIP2 Message Format
The message format used with RIP2 is an extension of the RIP1 format:
RIP version 2 also adds a 16-bit route tag that is retained and sent with router updates. It can be used
to identify the origin of the route.
Because the version number in RIP2 occupies the same octet as in RIP1, both versions of the protocols
can be used on a given router simultaneously without interference.
RIP Global Settings
To setup RIP for the IP interfaces configured on the Switch, the user must first globally enable RIP
and then configure RIP settings for the individual IP interfaces. To globally enable RIP on the Switch,
open the Layer 3 Features and then open the RIP folder and click on the RIP Global Settings link to
access the following screen: