TCP/IP Tutorial and Technical Overview - IBM Redbooks

5.4.2 RIP-2 limitations
Authentication Type This field defines the remaining 16 bytes of the
authentication entry. A value of 0 indicates no
authentication. A value of two indicates the authentication
data field contains password data.
Authentication Data This field contains a 16-byte password.
Route Tag This field is intended to differentiate between internal and
external routes. Internal routes are learned through RIP-2
within the same network or AS.
Subnet Mask This field contains the subnet mask of the referenced
network.
Next Hop This field contains a recommendation about the next hop
the router should use when sending datagrams to the
referenced network.
RIP-2 was developed to address many of the limitations observed in RIP-1.
However, the path cost limits and slow convergence inherent in RIP-1 networks
are also concerns in RIP-2 environments.
In addition to these concerns, there are limitations to the RIP-2 authentication
process. The RIP-2 standard does not encrypt the authentication password. It is
transmitted in clear text. This makes the network vulnerable to attack by anyone
with direct physical access to the environment.
5.5 RIPng for IPv6
RIPng was developed to allow routers within an IPv6-based network to exchange
information used to compute routes. It is documented in RFC 2080. We provide
additional information regarding IPv6 in 9.1, “IPv6 introduction” on page 328.
Like the other protocols in the RIP family, RIPng is a distance vector protocol
designed for use within a small autonomous system. RIPng uses the same
algorithms, timers, and logic used in RIP-2.
RIPng has many of the same limitations inherent in other distance vector
protocols. Path cost restrictions and convergence time remain a concern in
RIPng networks.
192 TCP/IP Tutorial and Technical Overview