4.5.2 Ensure RIP is set to check for zero values in reserved fields


The router should check that fields that the RFC requires must be 0 are, in fact, 0.


Where it is deployed, RIP routing is vital for normal operation of an organization's network infrastructure. Correct route information is required for routers to correctly direct traffic through the network.

The RFCs relating to RIP define a number of reserved fields in the packet format for future use. Those fields not used in the protocol version used should be set to 0.

If a packet is received with reserved fields set to a value other than 0 then it is breaking the RFC standards and may be an attempt to attack the router. In almost all network environments there is no reason for such a packet to exist, so JUNOS's default behavior of ignoring them should be used.


If you have deployed RIP in your network and disabled zero value checking of reserved fields, you should re-enable it by issuing the following command from the [edit protocols rip] hierarchy:

[edit protocols rip]
user@host#set check-zero

Default Value:

When RIP is used, check-zero is the default setting.

See Also


Item Details


References: 800-53|CM-6, CSCv7|11

Plugin: Juniper

Control ID: 01b380f58eb88b8dd1cd1b6db875763f677082500fe949558102847eb7b31cbf