Deployment Guide

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4.3.2.5 Unicast Routing Flow Table
The Unicast Routing Flow Table supports routing for potentially large numbers of IPv4 and IPv6 flow entries
using the hardware L3 tables.
The Unicast Routing Flow Table is a single table organized as two mutually exclusive logical subtables by IP
protocol, and supports flow entry types listed in Table 23. One table number is used for both logical tables.
Table 23. Unicast Routing Flow Table Entry Types
Type
Table
Prerequisite(s)
Description
IPv4 Unicast
Table 40
Ethertype=0x0800
Matches routed unicast IPv4
packets. The Goto-Table
instruction specifies the Policy
ACL Table.
IPv6 Unicast
Table 41
Ethertype=0x86dd
Matches routed unicast IPv6
packets. The Goto-Table
instruction specifies the Policy
ACL Table.
4.3.2.5.1 Match Criteria, Instructions, Actions/Action List/Action Set, Counters, Flow Expiry
Table 24. Unicast Routing Flow Table IPv4 Header Match Fields
Field
Bits
Maskable
Optional
Description
ETH_TYPE
16
No
No
Must be 0x0800
VRF
16
No
Yes
If omitted or zero indicates the default routing table.
IPv4 DST
12
Yes
No
Must be a unicast IPv4 address. Prefix maskable only,
mask used for LPM forwarding.
Table 25. Unicast Routing Flow Table IPv6 Header Match Fields
Field
Bits
Maskable
Optional
Description
ETH_TYPE
16
No
No
Must be 0x86dd
VRF
16
No
Yes
If omitted or zero indicates the default routing table.
IPV6_DST
128
Yes
No
Must be a unicast IPv6 address. Prefix maskable only,
used for LPM forwarding.
Note: Exact match rules must be given higher priority assignments than any LPM prefix match rules. In any
event, the hardware evaluates exact match rules before any wildcard rules.
Note: Rules that specify a nonzero VRF must have higher relative priority than other overlapping rules. The
wildcard rules are effectively “global” or “default” in that they are matched last, that is, if no specific VRF
rule matches the packet. If the packet VRF is zero it can only match one of the wildcard rules.
Default next table on a miss is the ACL Policy Flow Table.
Table 26: Unicast Routing Flow Table Instructions
Name
Argument
Description
Write-Actions
Action set
Only the actions in Table 27 can be specified.
Clear-Actions
-
Used to delete any forwarding decision so that the packet will be dropped.
Other instruction types, specifically Apply Actions, are not supported.
Table 27: Unicast Routing Flow Table Actions