- play_arrow Configuring Firewall Filters
- play_arrow Understanding How Firewall Filters Protect Your Network
- Firewall Filters Overview
- Router Data Flow Overview
- Stateless Firewall Filter Overview
- Understanding How to Use Standard Firewall Filters
- Understanding How Firewall Filters Control Packet Flows
- Stateless Firewall Filter Components
- Stateless Firewall Filter Application Points
- How Standard Firewall Filters Evaluate Packets
- Understanding Firewall Filter Fast Lookup Filter
- Understanding Egress Firewall Filters with PVLANs
- Selective Class-based Filtering on PTX Routers
- Guidelines for Configuring Firewall Filters
- Guidelines for Applying Standard Firewall Filters
- Supported Standards for Filtering
- Monitoring Firewall Filter Traffic
- Troubleshooting Firewall Filters
- play_arrow Firewall Filter Match Conditions and Actions
- Overview of Firewall Filters (OCX Series)
- Overview of Firewall Filter Profiles on ACX Series Routers (Junos OS Evolved)
- Understanding Firewall Filter Match Conditions
- Understanding Firewall Filter Planning
- Understanding How Firewall Filters Are Evaluated
- Understanding Firewall Filter Match Conditions
- Firewall Filter Flexible Match Conditions
- Firewall Filter Nonterminating Actions
- Firewall Filter Terminating Actions
- Firewall Filter Match Conditions and Actions (ACX Series Routers)
- Firewall Filter Match Conditions and Actions in ACX Series Routers (Junos OS Evolved)
- Firewall Filter Match Conditions for Protocol-Independent Traffic
- Firewall Filter Match Conditions for IPv4 Traffic
- Firewall Filter Match Conditions for IPv6 Traffic
- Firewall Filter Match Conditions Based on Numbers or Text Aliases
- Firewall Filter Match Conditions Based on Bit-Field Values
- Firewall Filter Match Conditions Based on Address Fields
- Firewall Filter Match Conditions Based on Address Classes
- Understanding IP-Based Filtering and Selective Port Mirroring of MPLS Traffic
- Firewall Filter Match Conditions for MPLS Traffic
- Firewall Filter Match Conditions for MPLS-Tagged IPv4 or IPv6 Traffic
- Firewall Filter Match Conditions for VPLS Traffic
- Firewall Filter Match Conditions for Layer 2 CCC Traffic
- Firewall Filter Match Conditions for Layer 2 Bridging Traffic
- Firewall Filter Support on Loopback Interface
- play_arrow Applying Firewall Filters to Routing Engine Traffic
- Configuring Logical Units on the Loopback Interface for Routing Instances in Layer 3 VPNs
- Example: Configuring a Filter to Limit TCP Access to a Port Based On a Prefix List
- Example: Configuring a Stateless Firewall Filter to Accept Traffic from Trusted Sources
- Example: Configure a Filter to Block Telnet and SSH Access
- Example: Configuring a Filter to Block TFTP Access
- Example: Configuring a Filter to Accept Packets Based on IPv6 TCP Flags
- Example: Configuring a Filter to Block TCP Access to a Port Except from Specified BGP Peers
- Example: Configuring a Stateless Firewall Filter to Protect Against TCP and ICMP Floods
- Example: Protecting the Routing Engine with a Packets-Per-Second Rate Limiting Filter
- Example: Configuring a Filter to Exclude DHCPv6 and ICMPv6 Control Traffic for LAC Subscriber
- Port Number Requirements for DHCP Firewall Filters
- Example: Configuring a DHCP Firewall Filter to Protect the Routing Engine
- play_arrow Applying Firewall Filters to Transit Traffic
- Example: Configuring a Filter for Use as an Ingress Queuing Filter
- Example: Configuring a Filter to Match on IPv6 Flags
- Example: Configuring a Filter to Match on Port and Protocol Fields
- Example: Configuring a Filter to Count Accepted and Rejected Packets
- Example: Configuring a Filter to Count and Discard IP Options Packets
- Example: Configuring a Filter to Count IP Options Packets
- Example: Configuring a Filter to Count and Sample Accepted Packets
- Example: Configuring a Filter to Set the DSCP Bit to Zero
- Example: Configuring a Filter to Set the DSCP Bit to Zero
- Example: Configuring a Filter to Match on Two Unrelated Criteria
- Example: Configuring a Filter to Accept DHCP Packets Based on Address
- Example: Configuring a Filter to Accept OSPF Packets from a Prefix
- Example: Configuring a Stateless Firewall Filter to Handle Fragments
- Configuring a Firewall Filter to Prevent or Allow IPv4 Packet Fragmentation
- Configuring a Firewall Filter to Discard Ingress IPv6 Packets with a Mobility Extension Header
- Example: Configuring an Egress Filter Based on IPv6 Source or Destination IP Addresses
- Example: Configuring a Rate-Limiting Filter Based on Destination Class
- play_arrow Configuring Firewall Filters in Logical Systems
- Firewall Filters in Logical Systems Overview
- Guidelines for Configuring and Applying Firewall Filters in Logical Systems
- References from a Firewall Filter in a Logical System to Subordinate Objects
- References from a Firewall Filter in a Logical System to Nonfirewall Objects
- References from a Nonfirewall Object in a Logical System to a Firewall Filter
- Example: Configuring Filter-Based Forwarding
- Example: Configuring Filter-Based Forwarding on Logical Systems
- Example: Configuring a Stateless Firewall Filter to Protect a Logical System Against ICMP Floods
- Example: Configuring a Stateless Firewall Filter to Protect a Logical System Against ICMP Floods
- Unsupported Firewall Filter Statements for Logical Systems
- Unsupported Actions for Firewall Filters in Logical Systems
- Filter-Based Forwarding for Routing Instances
- Forwarding Table Filters for Routing Instances on ACX Series Routers
- Configuring Forwarding Table Filters
- play_arrow Configuring Firewall Filter Accounting and Logging
- play_arrow Attaching Multiple Firewall Filters to a Single Interface
- Applying Firewall Filters to Interfaces
- Configuring Firewall Filters
- Multifield Classifier Example: Configuring Multifield Classification
- Multifield Classifier for Ingress Queuing on MX Series Routers with MPC
- Assigning Multifield Classifiers in Firewall Filters to Specify Packet-Forwarding Behavior (CLI Procedure)
- Understanding Multiple Firewall Filters in a Nested Configuration
- Guidelines for Nesting References to Multiple Firewall Filters
- Understanding Multiple Firewall Filters Applied as a List
- Guidelines for Applying Multiple Firewall Filters as a List
- Example: Applying Lists of Multiple Firewall Filters
- Example: Nesting References to Multiple Firewall Filters
- Example: Filtering Packets Received on an Interface Set
- play_arrow Attaching a Single Firewall Filter to Multiple Interfaces
- Interface-Specific Firewall Filter Instances Overview
- Interface-Specific Firewall Filter Instances Overview
- Filtering Packets Received on a Set of Interface Groups Overview
- Filtering Packets Received on an Interface Set Overview
- Example: Configuring Interface-Specific Firewall Filter Counters
- Example: Configuring a Stateless Firewall Filter on an Interface Group
- play_arrow Configuring Filter-Based Tunneling Across IP Networks
- Understanding Filter-Based Tunneling Across IPv4 Networks
- Firewall Filter-Based L2TP Tunneling in IPv4 Networks Overview
- Interfaces That Support Filter-Based Tunneling Across IPv4 Networks
- Components of Filter-Based Tunneling Across IPv4 Networks
- Example: Transporting IPv6 Traffic Across IPv4 Using Filter-Based Tunneling
- play_arrow Configuring Service Filters
- Service Filter Overview
- How Service Filters Evaluate Packets
- Guidelines for Configuring Service Filters
- Guidelines for Applying Service Filters
- Example: Configuring and Applying Service Filters
- Service Filter Match Conditions for IPv4 or IPv6 Traffic
- Service Filter Nonterminating Actions
- Service Filter Terminating Actions
- play_arrow Configuring Simple Filters
- play_arrow Configuring Layer 2 Firewall Filters
- Understanding Firewall Filters Used to Control Traffic Within Bridge Domains and VPLS Instances
- Example: Configuring Filtering of Frames by MAC Address
- Example: Configuring Filtering of Frames by IEEE 802.1p Bits
- Example: Configuring Filtering of Frames by Packet Loss Priority
- Example: Configuring Policing and Marking of Traffic Entering a VPLS Core
- Understanding Firewall Filters on OVSDB-Managed Interfaces
- Example: Applying a Firewall Filter to OVSDB-Managed Interfaces
- play_arrow Configuring Firewall Filters for Forwarding, Fragments, and Policing
- Filter-Based Forwarding Overview
- Firewall Filters That Handle Fragmented Packets Overview
- Stateless Firewall Filters That Reference Policers Overview
- Example: Configuring Filter-Based Forwarding on the Source Address
- Example: Configuring Filter-Based Forwarding to a Specific Outgoing Interface or Destination IP Address
- play_arrow Configuring Firewall Filters (EX Series Switches)
- Firewall Filters for EX Series Switches Overview
- Understanding Planning of Firewall Filters
- Understanding Firewall Filter Match Conditions
- Understanding How Firewall Filters Control Packet Flows
- Understanding How Firewall Filters Are Evaluated
- Understanding Firewall Filter Processing Points for Bridged and Routed Packets on EX Series Switches
- Firewall Filter Match Conditions, Actions, and Action Modifiers for EX Series Switches
- Platform Support for Firewall Filter Match Conditions, Actions, and Action Modifiers on EX Series Switches
- Support for Match Conditions and Actions for Loopback Firewall Filters on Switches
- Configuring Firewall Filters (CLI Procedure)
- Understanding How Firewall Filters Test a Packet's Protocol
- Understanding Filter-Based Forwarding for EX Series Switches
- Example: Configuring Firewall Filters for Port, VLAN, and Router Traffic on EX Series Switches
- Example: Configuring a Firewall Filter on a Management Interface on an EX Series Switch
- Example: Using Filter-Based Forwarding to Route Application Traffic to a Security Device
- Example: Applying Firewall Filters to Multiple Supplicants on Interfaces Enabled for 802.1X or MAC RADIUS Authentication
- Verifying That Policers Are Operational
- Troubleshooting Firewall Filters
- play_arrow Configuring Firewall Filters (QFX Series Switches, EX4600 Switches, PTX Series Routers)
- Overview of Firewall Filters (QFX Series)
- Understanding Firewall Filter Planning
- Planning the Number of Firewall Filters to Create
- Firewall Filter Match Conditions and Actions (QFX and EX Series Switches)
- Firewall Filter Match Conditions and Actions (QFX10000 Switches)
- Firewall Filter Match Conditions and Actions (PTX Series Routers)
- Firewall and Policing Differences Between PTX Series Packet Transport Routers and T Series Matrix Routers
- Configuring Firewall Filters
- Applying Firewall Filters to Interfaces
- Overview of MPLS Firewall Filters on Loopback Interface
- Configuring MPLS Firewall Filters and Policers on Switches
- Configuring MPLS Firewall Filters and Policers on Routers
- Configuring MPLS Firewall Filters and Policers
- Understanding How a Firewall Filter Tests a Protocol
- Understanding Firewall Filter Processing Points for Bridged and Routed Packets
- Understanding Filter-Based Forwarding
- Example: Using Filter-Based Forwarding to Route Application Traffic to a Security Device
- Configuring a Firewall Filter to De-Encapsulate GRE or IPIP Traffic
- Verifying That Firewall Filters Are Operational
- Monitoring Firewall Filter Traffic
- Troubleshooting Firewall Filter Configuration
- play_arrow Configuring Firewall Filter Accounting and Logging (EX9200 Switches)
-
- play_arrow Configuring Traffic Policers
- play_arrow Understanding Traffic Policers
- Policer Implementation Overview
- ARP Policer Overview
- Example: Configuring ARP Policer
- Understanding the Benefits of Policers and Token Bucket Algorithms
- Determining Proper Burst Size for Traffic Policers
- Controlling Network Access Using Traffic Policing Overview
- Traffic Policer Types
- Order of Policer and Firewall Filter Operations
- Understanding the Frame Length for Policing Packets
- Supported Standards for Policing
- Hierarchical Policer Configuration Overview
- Understanding Enhanced Hierarchical Policers
- Packets-Per-Second (pps)-Based Policer Overview
- Guidelines for Applying Traffic Policers
- Policer Support for Aggregated Ethernet Interfaces Overview
- Example: Configuring a Physical Interface Policer for Aggregate Traffic at a Physical Interface
- Firewall and Policing Differences Between PTX Series Packet Transport Routers and T Series Matrix Routers
- Hierarchical Policers on ACX Series Routers Overview
- Guidelines for Configuring Hierarchical Policers on ACX Series Routers
- Hierarchical Policer Modes on ACX Series Routers
- Processing of Hierarchical Policers on ACX Series Routers
- Actions Performed for Hierarchical Policers on ACX Series Routers
- Configuring Aggregate Parent and Child Policers on ACX Series Routers
- play_arrow Configuring Policer Rate Limits and Actions
- play_arrow Configuring Layer 2 Policers
- Hierarchical Policers
- Configuring a Policer Overhead
- Two-Color and Three-Color Policers at Layer 2
- Layer 2 Traffic Policing at the Pseudowire Overview
- Configuring a Two-Color Layer 2 Policer for the Pseudowire
- Configuring a Three-Color Layer 2 Policer for the Pseudowire
- Applying the Policers to Dynamic Profile Interfaces
- Attaching Dynamic Profiles to Routing Instances
- Using Variables for Layer 2 Traffic Policing at the Pseudowire Overview
- Configuring a Policer for the Complex Configuration
- Creating a Dynamic Profile for the Complex Configuration
- Attaching Dynamic Profiles to Routing Instances for the Complex Configuration
- Verifying Layer 2 Traffic Policers on VPLS Connections
- Understanding Policers on OVSDB-Managed Interfaces
- Example: Applying a Policer to OVSDB-Managed Interfaces
- play_arrow Configuring Two-Color and Three-Color Traffic Policers at Layer 3
- Two-Color Policer Configuration Overview
- Basic Single-Rate Two-Color Policers
- Bandwidth Policers
- Prefix-Specific Counting and Policing Actions
- Policer Overhead to Account for Rate Shaping in the Traffic Manager
- Three-Color Policer Configuration Overview
- Applying Policers
- Three-Color Policer Configuration Guidelines
- Basic Single-Rate Three-Color Policers
- Basic Two-Rate Three-Color Policers
- Example: Configuring a Two-Rate Three-Color Policer
- play_arrow Configuring Logical and Physical Interface Traffic Policers at Layer 3
- play_arrow Configuring Policers on Switches
- Overview of Policers
- Traffic Policer Types
- Understanding the Use of Policers in Firewall Filters
- Understanding Tricolor Marking Architecture
- Configuring Policers to Control Traffic Rates (CLI Procedure)
- Configuring Tricolor Marking Policers
- Understanding Policers with Link Aggregation Groups
- Understanding Color-Blind Mode for Single-Rate Tricolor Marking
- Understanding Color-Aware Mode for Single-Rate Tricolor Marking
- Understanding Color-Blind Mode for Two-Rate Tricolor Marking
- Understanding Color-Aware Mode for Two-Rate Tricolor Marking
- Example: Using Two-Color Policers and Prefix Lists
- Example: Using Policers to Manage Oversubscription
- Assigning Forwarding Classes and Loss Priority
- Configuring Color-Blind Egress Policers for Medium-Low PLP
- Configuring Two-Color and Three-Color Policers to Control Traffic Rates
- Verifying That Two-Color Policers Are Operational
- Verifying That Three-Color Policers Are Operational
- Troubleshooting Policer Configuration
- Troubleshooting Policer Configuration
-
- play_arrow Configuration Statements and Operational Commands
- play_arrow Troubleshooting
- play_arrow Knowledge Base
-
ON THIS PAGE
Example: Configuring Routing Policy Prefix Lists
In Junos OS, prefix lists provide one method of defining a set of routes. Junos OS
provides other methods of accomplishing the same task, such as route filters. A prefix
list is a listing of IP prefixes that represent a set of routes that are used as match
criteria in an applied policy. Such a list might be useful for representing a list of
customer routes in your autonomous system (AS). A prefix list is given a name and is
configured within the [edit policy-options] configuration hierarchy.
Requirements
No special configuration beyond device initialization is required before configuring this example.
Updated and re-validated using Junos OS Release 22.1R1.
Overview
Prefix lists are similar to a list of route filters. The functional difference
between route filters and prefix lists is that you cannot specify a range using a
prefix list. You can simulate a range using a prefix list by including additional
prefixes in the list, or by using two prefix lists, one shorter and one longer,
setting one to accept and the other to reject. You can also filter a prefix list
using the prefix-list-filter match condition. Your choices are
exact, longer, and orlonger.
The benefit of a prefix list over a list of route filters is seen when the prefixes are referenced in several different locations. For instance, a prefix list can be referenced in a BGP import policy, an export policy, an RPF policy, in firewall filters, in loopback filters, in setting a multicast scope, and so on.
When your list of prefixes changes, rather than trying to remember the many different locations prefixes are configured, you can instead update the prefix list, changing the prefix one time instead of multiple times. This helps to reduce the likelihood of configuration errors, such as mistyping the address in a location or forgetting to update one or more locations.
Prefix lists also help when managing a large number of devices. You can write the various filters and policies as generically as possible, referencing prefix lists instead of specific IP addresses. The more complex logic in the filters and policies has to be written only one time, with minimal per-device and per-site customizations.
As shown in Figure 1, each
router
in AS
65000
has customer routes. Device R1 assigns customer routes within the 172.16.1.0/24
subnet. Device R2 and Device R3 assign customer routes within the 172.16.2.0/24 and
172.16.3.0/24 subnets, respectively. Device R1 has been designated the central point
in AS
65000
to maintain a complete list of customer routes. Device R1 has a prefix list called
customers, as follows:
user@R1# show policy-options
prefix-list customers {
172.16.1.16/28;
172.16.1.32/28;
172.16.1.48/28;
172.16.1.64/28;
172.16.2.16/28;
172.16.2.32/28;
172.16.2.48/28;
172.16.2.64/28;
172.16.3.16/28;
172.16.3.32/28;
172.16.3.48/28;
172.16.3.64/28;
}
As you can see, the prefix list does not contain a match type for each route (as you would see with a route filter). This is an important point when using a prefix list in a policy. Routes match only if they exactly match one of the prefixes in the list. In other words, each route in the list must appear in the routing table exactly as it is configured in the prefix list.
You reference the prefix list as a match criterion within a policy like this:
user@R1# show policy-options
policy-statement customer-routes {
term get-routes {
from {
prefix-list customers;
}
then accept;
}
term others {
then reject;
}
}
In this example, all the routes in the customers prefix list appear
in the routing table on Device R1. Device R2 and Device R3 export to Device R1
static routes to their customers.
As previously mentioned, you can use the prefix-list-filter match
condition with the exact, longer, or
orlonger match type. This provides a way to avoid the prefix
list exact-match limitation of prefix lists. For example:
user@R1# show policy-options
policy-statement customer-routes {
term get-routes {
from {
prefix-list-filter customers orlonger;
}
then accept;
}
term others {
then reject;
}
}
The example demonstrates the effects of both the prefix-list match
condition and the prefix-list-filter match condition.
Topology
Figure 1 shows the sample network.
CLI Quick Configuration shows the configuration for all of the devices in Figure 1.
The section #configuration449__policy-prefix-list-st describes the steps on Device R1.
Configuration
CLI Quick Configuration
To quickly configure this example, copy the following commands, paste them into a
text file, remove any line breaks, change any details necessary to match your
network configuration, and then copy and paste the commands into the CLI at the
[edit] hierarchy level.
Device R1
set interfaces ge-0/0/0 unit 0 description to_R2 set interfaces ge-0/0/0 unit 0 family inet address 10.0.0.1/30 set interfaces ge-0/0/1 unit 0 description to_R3 set interfaces ge-0/0/1 unit 0 family inet address 10.0.0.5/30 set interfaces ge-0/0/2 unit 0 description to_R4 set interfaces ge-0/0/2 unit 0 family inet address 10.1.0.5/30 set interfaces lo0 unit 0 family inet address 192.168.0.1/32 set policy-options prefix-list customers 172.16.1.16/28 set policy-options prefix-list customers 172.16.1.32/28 set policy-options prefix-list customers 172.16.1.48/28 set policy-options prefix-list customers 172.16.1.64/28 set policy-options prefix-list customers 172.16.2.16/28 set policy-options prefix-list customers 172.16.2.32/28 set policy-options prefix-list customers 172.16.2.48/28 set policy-options prefix-list customers 172.16.2.64/28 set policy-options prefix-list customers 172.16.3.16/28 set policy-options prefix-list customers 172.16.3.32/28 set policy-options prefix-list customers 172.16.3.48/28 set policy-options prefix-list customers 172.16.3.64/28 set policy-options policy-statement customer-routes term get-routes from prefix-list customers set policy-options policy-statement customer-routes term get-routes then accept set policy-options policy-statement customer-routes term others then reject set routing-options router-id 192.168.0.1 set routing-options autonomous-system 65000 set routing-options static route 172.16.1.16/28 discard set routing-options static route 172.16.1.32/28 discard set routing-options static route 172.16.1.48/28 discard set routing-options static route 172.16.1.64/28 discard set protocols bgp group int type internal set protocols bgp group int local-address 192.168.0.1 set protocols bgp group int neighbor 192.168.0.2 set protocols bgp group int neighbor 192.168.0.3 set protocols bgp group to_65001 type external set protocols bgp group to_65001 export customer-routes set protocols bgp group to_65001 neighbor 10.1.0.6 peer-as 65001 set protocols ospf area 0.0.0.0 interface ge-0/0/0.0 set protocols ospf area 0.0.0.0 interface ge-0/0/1.0 set protocols ospf area 0.0.0.0 interface lo0.0 passive
Device R2
set interfaces ge-0/0/0 unit 0 description to_R1 set interfaces ge-0/0/0 unit 0 family inet address 10.0.0.2/30 set interfaces ge-0/0/1 unit 0 description to_R3 set interfaces ge-0/0/1 unit 0 family inet address 10.1.0.1/30 set interfaces lo0 unit 0 family inet address 192.168.0.2/32 set policy-options policy-statement send-static term 1 from protocol static set policy-options policy-statement send-static term 1 then accept set routing-options router-id 192.168.0.2 set routing-options autonomous-system 65000 set routing-options static route 172.16.2.16/28 discard set routing-options static route 172.16.2.32/28 discard set routing-options static route 172.16.2.48/28 discard set routing-options static route 172.16.2.64/28 discard set protocols bgp group int type internal set protocols bgp group int local-address 192.168.0.2 set protocols bgp group int neighbor 192.168.0.1 export send-static set protocols bgp group int neighbor 192.168.0.3 set protocols ospf area 0.0.0.0 interface ge-0/0/0.0 set protocols ospf area 0.0.0.0 interface ge-0/0/1.0 set protocols ospf area 0.0.0.0 interface lo0.0 passive
Device R3
set interfaces ge-0/0/0 unit 0 description to_R1 set interfaces ge-0/0/0 unit 0 family inet address 10.0.0.6/30 set interfaces ge-0/0/1 unit 0 description to_R2 set interfaces ge-0/0/1 unit 0 family inet address 10.1.0.2/30 set interfaces lo0 unit 0 family inet address 192.168.0.3/32 set policy-options policy-statement send-static term 1 from protocol static set policy-options policy-statement send-static term 1 then accept set routing-options router-id 192.168.0.3 set routing-options autonomous-system 65000 set routing-options static route 172.16.3.16/28 discard set routing-options static route 172.16.3.32/28 discard set routing-options static route 172.16.3.48/28 discard set routing-options static route 172.16.3.64/28 discard set protocols bgp group int type internal set protocols bgp group int local-address 192.168.0.3 set protocols bgp group int neighbor 192.168.0.1 export send-static set protocols bgp group int neighbor 192.168.0.2 set protocols ospf area 0.0.0.0 interface ge-0/0/0.0 set protocols ospf area 0.0.0.0 interface ge-0/0/1.0 set protocols ospf area 0.0.0.0 interface lo0.0 passive
Device R4
set interfaces ge-0/0/0 unit 0 description to_R1 set interfaces ge-0/0/0 unit 0 family inet address 10.1.0.6/30 set interfaces lo0 unit 0 family inet address 192.168.0.4/32 set routing-options autonomous-system 65001 set protocols bgp group ext type external set protocols bgp group ext peer-as 65000 set protocols bgp group ext neighbor 10.1.0.5
Procedure
Step-by-Step Procedure
We are showing the step-by-step procedure to configure R1. The other routers have a similar step-by-step process. The following example requires that you navigate various levels in the configuration hierarchy. For information about navigating the CLI, see Use the CLI Editor in Configuration Mode in the Junos OS CLI User Guide.
To configure R1:
Configure the interfaces.
content_copy zoom_out_map[edit] user@R1# set interfaces ge-0/0/0 unit 0 description to_R2 user@R1# set interfaces ge-0/0/0 unit 0 family inet address 10.0.0.1/30 user@R1# set interfaces ge-0/0/1 unit 0 description to_R3 user@R1# set interfaces ge-0/0/1 unit 0 family inet address 10.0.0.5/30 user@R1# set interfaces ge-0/0/2 unit 0 description to_R4 user@R1# set interfaces ge-0/0/2 unit 0 family inet address 10.1.0.5/30 user@R1# set interfaces lo0 unit 0 family inet address 192.168.0.1/32
Configure the internal BGP (IBGP) peerings to R2 and R3.
content_copy zoom_out_map[edit] user@R1# set protocols bgp group int type internal user@R1# set protocols bgp group int local-address 192.168.0.1 user@R1# set protocols bgp group int neighbor 192.168.0.2 user@R1# set protocols bgp group int neighbor 192.168.0.3
Configure the external BGP (EBGP) peering to R4. The export policy configuration is shown in a later step.
content_copy zoom_out_map[edit] user@R1# set protocols bgp group to_65001 type external user@R1# set protocols bgp group to_65001 export customer-routes user@R1# set protocols bgp group to_65001 neighbor 10.1.0.6 peer-as 65001
Configure the OSPF peerings to R2 and R3. The OSPF protocol provides the learning of the loopback address for each device which allows the IBGP peerings to establish.
content_copy zoom_out_map[edit] user@R1# set protocols ospf area 0.0.0.0 interface ge-0/0/0.0 user@R1# set protocols ospf area 0.0.0.0 interface ge-0/0/1.0 user@R1# set protocols ospf area 0.0.0.0 interface lo0.0 passive
Configure the prefix list.
content_copy zoom_out_map[edit] user@R1# set policy-options prefix-list customers 172.16.1.16/28 user@R1# set policy-options prefix-list customers 172.16.1.32/28 user@R1# set policy-options prefix-list customers 172.16.1.48/28 user@R1# set policy-options prefix-list customers 172.16.1.64/28 user@R1# set policy-options prefix-list customers 172.16.2.16/28 user@R1# set policy-options prefix-list customers 172.16.2.32/28 user@R1# set policy-options prefix-list customers 172.16.2.48/28 user@R1# set policy-options prefix-list customers 172.16.2.64/28 user@R1# set policy-options prefix-list customers 172.16.3.16/28 user@R1# set policy-options prefix-list customers 172.16.3.32/28 user@R1# set policy-options prefix-list customers 172.16.3.48/28 user@R1# set policy-options prefix-list customers 172.16.3.64/28
Configure the routing policy that references the prefix list as a match criterion.
content_copy zoom_out_map[edit] user@R1# set policy-options policy-statement customer-routes term get-routes from prefix-list customers user@R1# set policy-options policy-statement customer-routes term get-routes then accept user@R1# set policy-options policy-statement customer-routes term others then reject
Configure the static routes for the 172.16.1.0/24 network. We are using static routes to emulate the customer routes.
content_copy zoom_out_map[edit] user@R1# set routing-options static route 172.16.1.16/28 discard user@R1# set routing-options static route 172.16.1.32/28 discard user@R1# set routing-options static route 172.16.1.48/28 discard user@R1# set routing-options static route 172.16.1.64/28 discard
Configure the autonomous system (AS) number and router ID.
content_copy zoom_out_map[edit] user@R1# set routing-options router-id 192.168.0.1 user@R1# set routing-options autonomous-system 65000
Results
From configuration mode, confirm your configuration by entering the
show interfaces, show protocols,
show policy-options, and show
routing-options commands. If the output does not display the
intended configuration, repeat the instructions in this example to correct
the configuration.
user@R1# show interfaces
ge-0/0/0 {
unit 0 {
description to_R2;
family inet {
address 10.0.0.1/30;
}
}
}
ge-0/0/1 {
unit 0 {
description to_R3;
family inet {
address 10.0.0.5/30;
}
}
}
ge-0/0/2 {
unit 0 {
description to_R4;
family inet {
address 10.1.0.5/30;
}
}
}
lo0 {
unit 0 {
family inet {
address 192.168.0.1/32;
}
}
}user@R1# show protocols
bgp {
group int {
type internal;
local-address 192.168.0.1;
neighbor 192.168.0.2;
neighbor 192.168.0.3;
}
group to_65001 {
type external;
export customer-routes;
neighbor 10.1.0.6 {
peer-as 65001;
}
}
}
ospf {
area 0.0.0.0 {
interface ge-0/0/0.0;
interface ge-0/0/1.0;
interface lo0.0 {
passive;
}
}
}user@R1# show policy-options
prefix-list customers {
172.16.1.16/28;
172.16.1.32/28;
172.16.1.48/28;
172.16.1.64/28;
172.16.2.16/28;
172.16.2.32/28;
172.16.2.48/28;
172.16.2.64/28;
172.16.3.16/28;
172.16.3.32/28;
172.16.3.48/28;
172.16.3.64/28;
}
policy-statement customer-routes {
term get-routes {
from {
prefix-list customers;
}
then accept;
}
term others {
then reject;
}
}
user@R1# show routing-options
static {
route 172.16.1.16/28 discard;
route 172.16.1.32/28 discard;
route 172.16.1.48/28 discard;
route 172.16.1.64/28 discard;
}
router-id 192.168.0.1;
autonomous-system 65000;
If you are done configuring the device, enter commit from
configuration mode.
Verification
Confirm that the configuration is working properly.
- Verifying the Routes on R1
- Verifying the Route Advertisement to R4
- Experimenting with the prefix-list-filter Statement
Verifying the Routes on R1
Purpose
On R1, check the routes in the routing table.
Action
user@R1> show route terse 172.16/16 inet.0: 30 destinations, 30 routes (30 active, 0 holddown, 0 hidden) + = Active Route, - = Last Active, * = Both A V Destination P Prf Metric 1 Metric 2 Next hop AS path * ? 172.16.1.16/28 S 5 Discard * ? 172.16.1.32/28 S 5 Discard * ? 172.16.1.48/28 S 5 Discard * ? 172.16.1.64/28 S 5 Discard * ? 172.16.2.16/28 B 170 100 I unverified >10.0.0.2 * ? 172.16.2.32/28 B 170 100 I unverified >10.0.0.2 * ? 172.16.2.48/28 B 170 100 I unverified >10.0.0.2 * ? 172.16.2.64/28 B 170 100 I unverified >10.0.0.2 * ? 172.16.3.16/28 B 170 100 I unverified >10.0.0.6 * ? 172.16.3.32/28 B 170 100 I unverified >10.0.0.6 * ? 172.16.3.48/28 B 170 100 I unverified >10.0.0.6 * ? 172.16.3.64/28 B 170 100 I unverified >10.0.0.6
Meaning
Device R1 has learned its own static routes (S) and the BGP routes from Devices R2 and R3 (B).
Verifying the Route Advertisement to R4
Purpose
On R1, make sure that the customer routes are advertised to R4.
Action
user@R1> show route advertising-protocol bgp 10.1.0.6 inet.0: 30 destinations, 30 routes (30 active, 0 holddown, 0 hidden) Prefix Nexthop MED Lclpref AS path * 172.16.1.16/28 Self I * 172.16.1.32/28 Self I * 172.16.1.48/28 Self I * 172.16.1.64/28 Self I * 172.16.2.16/28 Self I * 172.16.2.32/28 Self I * 172.16.2.48/28 Self I * 172.16.2.64/28 Self I * 172.16.3.16/28 Self I * 172.16.3.32/28 Self I * 172.16.3.48/28 Self I * 172.16.3.64/28 Self I
Meaning
As expected, only the routes from the customer prefix list are advertised to R4.
Experimenting with the prefix-list-filter Statement
Purpose
See what can happen when you use prefix-list-filter instead
of prefix-list.
Action
On R3, add a static route that is longer than one of the existing static routes.
content_copy zoom_out_map[edit routing-options static] user@R3# set route 172.16.3.65/32 discard user@R3# commit
On R1, deactivate the prefix list and configure a prefix list filter with the
orlongermatch type.content_copy zoom_out_map[edit policy-options policy-statement customer-routes term get-routes] user@R1# deactivate from prefix-list customers user@R1# set from prefix-list-filter customers orlonger user@R1# commit
On R1, check which routes are advertised to R4.
content_copy zoom_out_mapuser@R1> show route advertising-protocol bgp 10.1.0.6 inet.0: 31 destinations, 31 routes (31 active, 0 holddown, 0 hidden) Prefix Nexthop MED Lclpref AS path * 172.16.1.16/28 Self I * 172.16.1.32/28 Self I * 172.16.1.48/28 Self I * 172.16.1.64/28 Self I * 172.16.2.16/28 Self I * 172.16.2.32/28 Self I * 172.16.2.48/28 Self I * 172.16.2.64/28 Self I * 172.16.3.16/28 Self I * 172.16.3.32/28 Self I * 172.16.3.48/28 Self I * 172.16.3.64/28 Self I * 172.16.3.65/32 Self I
Meaning
As expected, R1 is now advertising the 172.16.3.65/32 route to R4, even though 172.16.3.65/32 is not in the prefix list.
