Concept Guide

● Destination IP address and mask
● Source port
● Destination port
● TCP Flags
After you apply a redirect-list to an interface, all traffic passing through it is subjected to the rules defined in the redirect-list.
Traffic is forwarded based on the following:
● Next-hop addresses are verified. If the specified next hop is reachable, traffic is forwarded to the specified next-hop.
● If the specified next-hops are not reachable, the normal routing table is used to forward the traffic.
● Dell EMC Networking OS supports multiple next-hop entries in the redirect lists.
● Redirect-lists are applied at Ingress.
PBR with Redirect-to-Tunnel Option:
You can provide a tunnel ID for a redirect rule. In this case, the resolved next hop is the tunnel interface IP. The qualifiers of the
rule pertain to the inner IP details. You must provide a tunnel ID for the next hop to be a tunnel interface. If you do not provide
the tunnel destination IP as the next hop, the next hop is treated as an IPv4 next hop and not a tunnel next hop.
PBR with Multiple Tracking Option:
PBR with the multiple tracking option enabled extends and introduces the capabilities of object tracking to verify the next hop
IP address before forwarding the traffic to the next hop. The multiple tracking options feature is most suitable for routers
which have multiple devices as the next hop (primarily indirect next-hops and/or Tunnel Interfaces). These options allow you
to backup Indirect next-hop with another. Choose the specific Indirect next-hop and/or Tunnel interface which is available by
sending ICMP pings to verify the reach ability and/or check the Tunnel interface UP or DOWN status, and then route traffic out
to that next-hop and/or Tunnel Interface
Implementing PBR
● Non-contiguous bitmasks for PBR
● Hot-Lock PBR
Non-Contiguous Bitmasks for PBR
Non-contiguous bitmasks for PBR allows more granular and flexible control over routing policies. You can include or exclude
network addresses that are in the middle of a subnet can be included or excluded. Enter specific bitmasks using the dotted
decimal format.
Hot-Lock PBR
Ingress and egress Hot lock PBR allows you to add or delete new rules into an existing policy (already written into content
address memory [CAM]) without disruption to traffic flow. Existing entries in content addressable memory (CAM) are adjusted
to accommodate the new entries. Hot Lock PBR is enabled by default.
Configuration Task List for Policy-based Routing
This section explains how to configure PBR on the system.
● Create a Redirect List
● Create a Rule for a Redirect-list
● Create a Track-ID list
● Apply a Redirect-list to an Interface using a Redirect-group
PBR Exceptions (Permit)
To create an exception to a redirect list, use thepermit command. Exceptions are used when a forwarding decision should be
based on the routing table rather than a routing policy.
The Dell EMC Networking OS assigns the first available sequence number to a rule configured without a sequence number and
inserts the rule into the PBR CAM region next to the existing entries. Because the order of rules is important, ensure that you
configure any necessary sequence numbers.
Policy-based Routing (PBR)
583