User Manual

Configuring Advanced Routing Policies
262 Enterasys X-Pedition User Reference Manual
Examples of Export Policies
Example 1: Exporting to RIP
Exporting to RIP is controlled by any of protocol, interface or gateway. If more than one is
specified, they are processed from most general (protocol) to most specific (gateway).
It is not possible to set metrics for exporting RIP routes into RIP. Attempts to do this are silently
ignored.
If no export policy is specified, RIP and interface routes are exported into RIP. If any policy is
specified, the defaults are overridden; it is necessary to explicitly specify everything that should be
exported.
RIP version 1 assumes that all subnets of the shared network have the same subnet mask so it is
only able to propagate subnets of that network. RIP version 2 removes that restriction and is
capable of propagating all routes when not sending version 1 compatible updates.
To announce routes which specify a next hop of the loopback interface (i.e. static and internally
generated default routes) via RIP, it is necessary to specify the metric at some level in the export
policy. Just setting a default metric for RIP is not sufficient. This is a safeguard to verify that the
announcement is intended.
For all examples in this section, refer to the configuration shown in Figure 21 on page 256.
The following configuration commands for router R1:
• Determine the IP address for each interface
• Specify the static routes configured on the router
• Determine its RIP configuration
!++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
! Create the various IP interfaces.
!++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
interface create ip to-r2 address-netmask 120.190.1.1/16 port et.1.2
interface create ip to-r3 address-netmask 130.1.1.1/16 port et.1.3
interface create ip to-r41 address-netmask 140.1.1.1/24 port et.1.4
interface create ip to-r42 address-netmask 140.1.2.1/24 port et.1.5
interface create ip to-r6 address-netmask 160.1.1.1/16 port et.1.6
interface create ip to-r7 address-netmask 170.1.1.1/16 port et.1.7
!++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
! Configure a default route through 170.1.1.7
!++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
ip add route default gateway 170.1.1.7
!+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
! Configure default routes to the 135.3.0.0 subnets reachable through
! R3.
!+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++