Configuring Multi-Path Routing Policies

If a WXC ISM 200 has two possible WAN paths to a remote WX endpoint, you can designate one path as the primary and the other as the secondary. You can then route application traffic to the primary or secondary path based on the performance requirements of the application and the performance of the path.

To configure the J Series Services Router to support Multi-Path:

1. Specify a secondary address for the wx-slot/0/0 interface:

   user@host# set interfaces wx-6/0/0 unit 0 family inet filter input classify-secondary

   user@host# set interfaces wx-6/0/0 unit 0 family inet address 2.2.2.2/32 destination 10.8.51.3

   The secondary address (10.8.51.3) is displayed automatically in the WXOS Web interface.

2. Specify a firewall filter so that packets that have the secondary address as their source address are forwarded by the routing instance wx-multipath:

   user@host# set interfaces wx-6/0/0 unit 0 family inet filter input classify-secondary

   user@host# set firewall family inet filter classify-secondary term 1 from source-address 10.8.51.3

   user@host# set firewall family inet filter classify-secondary term 1 then routing-instance wx–multipath

   user@host# set firewall family inet filter classify-secondary term default then accept

3. Optionally, you can add an IP precedence or class-of-service DiffServ code point value to the firewall filter. For example, if the WXC ISM 200 is configured to mark packets for the secondary path with an IP precedence value of 2, use the following command to update the firewall filter:

   user@host# set firewall family inet filter classify-secondary term 1 from precedence 2

4. Define the routing instance wx-multipath to route the filtered packets to the appropriate WAN interface:

   user@host# set routing-instances wx–multipath instance-type forwarding routing-options static route 0.0.0.0/32 next-hop 10.8.4.1 retain

5. Import routes from default inet.0 routing table to the wx-multipath.inet routing table:

   user@host# set routing-options interface-routes rib-group inet fb1

   user@host# set routing-options rib-groups fb1 import-rib [ inet.0 wx-multipath.inet.0 ]

6. On both the local WXC ISM 200 and the remote WX endpoint:
   1. Enable Multi-Path and configure an IP precedence or DSCP value as a supplemental marking method (optional).
   2. Define the appropriate traffic classes, and define Multi-Path templates that specify the preferred path (primary or secondary) for each traffic class.
   3. Apply a template to the remote WX endpoint, and specify the congestion and latency thresholds for each path.

   The router for the remote WX endpoint must also be configured to support Multi-Path. For more information about configuring Multi-Path, see the WX/WXC Operator's Guide.