Transcript Route Tables, Configured Routes, & Route Filters

Advanced Juniper Networks Routing
Release 5.1, Revision 0
Module 9: Static Routes &
Routing Table Groups
Copyright © 2001, Juniper Networks, Inc.
Objectives
In this module, students will:
 Describe the default JUNOS Software route tables
 Explain the operation of rib-groups
 Configure static, aggregate, and generated routes
 Explain how route filters operate on prefixes
Copyright © 2001, Juniper Networks, Inc.
Configuring Static Routes
 Manually configured routes added to the routing table
 Once active, remain in the routing table until deleted
 Configured at the routing-options hierarchy level
[edit]
routing-options {
static {
defaults {
static-options;
}
route destination-prefix{
next-hop;
static-options;
}
Copyright © 2001, Juniper Networks, Inc.
Static Routes
 Valid next-hop options include:
– IP address
– Discard
– Reject
– Receive
– Label Switched Path
– Qualified Next-hop
 Other options include:
– Metric
– BGP Community
– BGP AS Path
– Preference
 Defaults section affects all static routes
Copyright © 2001, Juniper Networks, Inc.
Copyright © 2001, Juniper Networks, Inc.
Static Next-Hop Options (1 of 2)
 IP address
– Must be reachable across a directly connected interface
– Interface name is OK for a point-to-point link
 Discard
– Remove packet from the network silently
 Reject
– Remove packet from the network and return an ICMP
message of “administratively prohibited” to IP source
Copyright © 2001, Juniper Networks, Inc.
Static Next-Hop Options (2 of 2)
 Receive
– Sends traffic to the Routing Engine if the route matches a
configured /32 interface address
– Very useful in a VPN environment
 Label Switched Path
– Must be an active named LSP with the local router as the
ingress router
 Qualified Next-hop
– Allows a route to have multiple versions in the routing table
– Versions can have separate preference values, metrics, etc.
Copyright © 2001, Juniper Networks, Inc.
Routes in Multiple Tables
 It can be useful for a single route destination to appear
in more than one route table
– Virtual Private Networks
– Multicast Networks
 A rib-group is a convenient method for placing routes
in multiple locations
routing-options {
rib-groups {
group name {
import-policy [policy-name];
import-rib [routing-table-name];
export-rib routing-table-name;
}
}
}
Copyright © 2001, Juniper Networks, Inc.
Rib-Groups
 Created within the routing-options hierarchy level
 Import-rib states where to place routes
– Multiple tables can be listed
– The first table listed must be the primary rib
– Routes must exist in the primary rib before being placed into
any secondary routing tables
 Export-rib states where to retrieve routes
– Only a single routing table can be listed
– Route table must be the primary rib
Copyright © 2001, Juniper Networks, Inc.
Rib-Group Applications
 Routing protocols
– IS-IS
– OSPF
– RIP
– BGP
 Multicast protocols
– PIM
– MSDP
 Static routes
 Interface-routes
– Protocols Direct and Local
Copyright © 2001, Juniper Networks, Inc.
Rib-Group Configuration
 Created and named
routing-options {
rib-groups {
example-rib {
import-rib [inet.0 inet.2];
 Applied to routing protocols
protocols {
isis {
rib-group example-rib;
}
ospf {
rib-group example-rib;
}
 Applied to static and interface routes
routing-options {
interface-routes {
rib-group inet example-rib;
}
static {
rib-group example-rib;
}
Copyright © 2001, Juniper Networks, Inc.
Review Questions
Copyright © 2001, Juniper Networks, Inc.