Implementing Policy-Based Routing With Dell Networking Os - Dell Force10 Z9000 Configuration Manual

To enable a PBR, you create a redirect list. Redirect lists are defined by rules, or routing policies. The following parameters can be
defined in the routing policies or rules:
• IP address of the forwarding router (next-hop IP address)
• Protocol as defined in the header
• Source IP address and mask
• Destination IP address and mask
• Source port
• Destination port
• TCP Flags
Once a redirect-list is applied to an interface, all traffic passing through it is subjected to the rules defined in the redirect-list.
The traffic is forwarded based on the following:
• Next-hop addresses are verified. If the specified next hop is reachable, then the traffic is forwarded to the specified next-hop.
• If the specified next-hops are not reachable, then the normal routing table is used to forward the traffic.
• Dell Networking OS supports multiple next-hop entries in the redirect lists.
• Redirect-Lists are applied at Ingress.
PBR with Redirect-to-Tunnel Option:
The user can provide a tunnel id for a redirect rule. In this case, the resolved next hop would be the tunnel interface IP. The qualifiers
of the rule would be pertaining to the inner IP details. For next hop to be a tunnel interface user needs to provide tunnel id
mandatory. Instead if user provides the tunnel destination IP as next hop, that would be treated as IPv4 next hop and not tunnel next
hop.
PBR with Multiple Tacking Option:
Policy based routing with multiple tracking option extends and introduces the capabilities of object tracking to verify the next hop IP
address before forwarding the traffic to the next hop. The verification method is made transparent to the user. 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 in this case). It allows 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 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 Policy-based Routing with Dell Networking OS

• 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. Network addresses that are in the
middle of a subnet can be included or excluded. Specific bitmasks can be entered using the dotted decimal format.
Non-contiguous bitmask example
Dell#show ip redirect-list
IP redirect-list rcl0:
Defined as:
seq 5 permit ip 200.200.200.200 200.200.200.200 199.199.199.199 199.199.199.199
seq 10 redirect 1.1.1.2 tcp 234.224.234.234 255.234.234.234 222.222.222.222/24
seq 40 ack, Next-hop reachable(via Te 8/1)
Applied interfaces:
Te 8/2
Hot-Lock PBR
524
Policy-based Routing (PBR)