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IPv6 Prefix List

IPv6 prefix lists provide ordered sets of permit/deny rules for filtering IPv6 routes based on network prefix and prefix length, serving as a fundamental building block for IPv6 routing policy on NX-OS. Each entry supports exact match or range-based matching with configurable minimum and maximum prefix lengths, enabling precise control over which IPv6 routes are accepted or advertised by routing protocols. IPv6 prefix lists are commonly referenced by route maps and other routing policy constructs to implement granular IPv6 route filtering and traffic engineering.

Diagram
NameTypeConstraintMandatoryDefault Value
ipv6_prefix_listsList[ipv6_prefix_lists]No

ipv6_prefix_lists (nxos.devices.configuration)

Section titled “ipv6_prefix_lists (nxos.devices.configuration)”
NameTypeConstraintMandatoryDefault Value
nameStringYes
descriptionStringNo
entriesList[entries]No

entries (nxos.devices.configuration.ipv6_prefix_lists)

Section titled “entries (nxos.devices.configuration.ipv6_prefix_lists)”
NameTypeConstraintMandatoryDefault Value
seqIntegerYes
actionChoicepermit, denyNo
prefixIPNo
maskIntegermin: 0, max: 128No
geIntegermin: 0, max: 128No
leIntegermin: 0, max: 128No

Example 1: Simple IPv6 prefix list to match loopback addresses

nxos:
devices:
- name: SPINE1
configuration:
ipv6_prefix_lists:
- name: PLV6-LOOPBACKS
description: "Match all fabric IPv6 loopback /128 addresses"
entries:
- seq: 10
action: permit
prefix: 2001:db8:1::/48
ge: 128
le: 128

Example 2: Multiple IPv6 prefix lists for BGP route filtering

nxos:
devices:
- name: LEAF1
configuration:
ipv6_prefix_lists:
- name: PLV6-TENANT-NETS
description: "Permit tenant IPv6 prefixes"
entries:
- seq: 10
action: permit
prefix: 2001:db8:100::/48
- seq: 20
action: permit
prefix: 2001:db8:200::/48
- name: PLV6-DEFAULT-ONLY
description: "Permit IPv6 default route only"
entries:
- seq: 10
action: permit
prefix: ::/0

Example 3: IPv6 prefix list with range matching for route aggregation policy

nxos:
devices:
- name: BORDER-LEAF1
configuration:
ipv6_prefix_lists:
- name: PLV6-EXTERNAL-PREFIXES
description: "Accept external IPv6 routes between /32 and /64"
entries:
- seq: 10
action: deny
prefix: fc00::/7
- seq: 20
action: permit
prefix: ::/0
ge: 32
le: 64