User`s guide

Configuring IP Routing
Introduction to IP routing on the Pipeline
Pipeline User’s Guide Preliminary January 30, 1998 2-3
interfaces. If the Pipeline is configured for RIP, it also broadcasts its updated
routing table to other hosts.
Router-to-router connections
When the device connecting to the Pipeline is an IP router that belongs to an IP
network, the connection results in a route to that remote network (or subnet). For
example, Figure 2-1 shows a Pipeline connected to a remote router. The two
Ethernet segments are separate IP networks.
Figure 2-1. An IP routing connection between two networks
If a user (attached to the Pipeline) launches a Telnet session and enters an address
at a remote site (such as one on the other side of the CPE router), the remote
router receives the outbound TCP/IP packets and consults its routing table. If it
does not find a route to the target site, it either forwards the packets to its default
router or drops them, depending on how it is configured. If it finds a route to the
target site, it opens the appropriate profile and dials out.
When receiving a call, the Pipeline checks its Answer profile to verify that it can
accept incoming IP routing calls. Then it does the following:
• If the Answer profile does not have IP routing on, the Pipeline ends the call.
• If the Answer profile does have IP routing on, the Pipeline looks for a profile
that matches the IP address offered during PPP negotiation.
• If the Pipeline doesn’t find a matching Connection profile, it ends the call.
• If the Pipeline finds a matching profile, it authenticates the connection.
After a connection is established, the Pipeline adds a network route to its routing
table and begins functioning as an IP router between its local and WAN interface.
If the Pipeline is configured for RIP, it also broadcasts its updated routing table to
other hosts.
WAN
CPE Router
IP Adrs=10.9.8.15/29
IP Adrs=10.2.3.1/22