IPv6 Routes and Hosts in External Tables

ExtremeXOS allows you to store IPv6 routes and hosts in external LPM tables. You can configure the external LPM to contain IPv4 or IPv6 routes, or both. Internal LPM tables can store IPv4 or IPv6 routes, both, or neither, based on the configuration setting for external-tables.

The configure forwarding external-tables l3-only command using the ipv6 and ipv4-and-ipv6 variables supports larger IPv6 route and host scaling in external LPM tables.

When an external LPM table is configured for l3-only ipv6, no IPv6 routes or IPv6 hosts are stored in any of the internal hardware tables. This provides the highest IPv6 scale, and avoids contention with IP Multicast in the L3 Hash hardware table.

IPv6 hardware and slowpath forwarding are supported on user-created Virtual Routers, and IPv6 tunnels are only supported on VR-Default.

The size of the internal LPM tables, and the size of the L3 Hash and Next Hop tables are fixed for some platforms. The following tables list the hardware capacity for each of the tables shown in Hardware Forwarding Tables

Hardware Routing Table Configuration Capacities, Platforms without External Tables

Table	BlackDiamond 8900 xm-Series Modules and Summit X670 Switches	BlackDiamond 8000 a- and c-Series Modules	BlackDiamond 8000 e-Series Modules	BlackDiamond X8 Series Switches	Summit X440 Switches	Summit X460 Switches	Summit X670 Switches
Internal LPM	16352	12256	480	16352	32	12256	16352
External LPM	N/A	N/A	N/A	N/A	N/A	N/A	N/N
L3 Hash	8192	8192	2048	16384	512	16384	8192
Next Hop	8192	8192	2048	16384	512	16384	8192

Hardware Routing Table Configuration Capacities, Platforms with External Tables

	BlackDiamond 8900 xl-Series Modules and Summit X480 Switches ^a
Table	l2-only, acl-only, and none Options	l2-and-l3-and-acl and l2-and-l3-and-ipmc Options	l2-and-l3 Option	l3-only Option	l3-only ipv4-and-ipv6 Option	l3-only ipv6 Option
Internal LPM IPv4	16352	N/A	N/A	N/A	N/A	16352^c
Internal LPM IPv6	8176	8192^b	8192^b	8192^b	N/A	N/A
External LPM IPv4	N/A	131040	262112	524256	475104	N/A
External LPM IPv6	N/A	N/A	N/A	N/A	49152	245760
L3 Hash	16384	16384	16384	16384	16384	16384
Next Hop	16384	16384	16384	16384	16384	16384

^{a These platforms use additional external LPM
tables and the actual value depends on the configuration set with the configure forwarding
external-tables command.}

^{b In this configuration, the internal LPM table stores only IPv6
routes. All IPv4 routes are stored in the external LPM tables.}

^{c In this configuration, the internal LPM table stores
only IPv4 routes. All IPv6 routes are stored in the external LPM tables.}

The Summit X670-G2, X770 and BlackDiamond X8-100G4X have hardware forwarding tables internal to the switch chips that can be partitioned in a flexible manner. The Summit X670-G2 and X770 switches have the following configurable internal tables:

Summit X670-G2 and X770 Hardware Routing Table Configuration Capacities for Platforms with Configurable L2/L3 Internal Tables

L3 Characteristic	l2-and-l3	more l3-and-ipmc	more l2
L3 Hash IPv4 Unicast	96K	128K	16K
L3 Hash IPv6 Unicast	48K	48K	8K
Next Hop	48K	48K	48K
Internal IPv4 LPM	16K	16K	16K
Internal IPv6 LPM	8K	8K	8K
IPv4 hosts with min LPM routes (assumes 75% utilization of L3 hash table)	82K	106K	28K
IPv4 hosts with max LPM routes (assumes 75% utilization of L3 hash table)	72K	96K	12K
Remote IPv4 Host Entries (assumes 75% utilization of L3 hash table)	124K	172K	28K
IPv6 Host Entries (assumes 75% utilization of L3 hash table)	36K	36K	6K
IP multicast groups	4K	4K	4K
IP-multicast (s,v,g) entries (will depend on hash utilization)	72K	104K	16K

The Summit X460-G2, has hardware forwarding tables internal to the switch chips that can be partitioned in a flexible manner. The Summit X460-G2 has the following configurable internal tables:

Summit X460-G2 Hardware Routing Table Configuration Capacities for Platforms with Configurable L2/L3 Internal Tables

L3 Characteristic	l2-and-l3	more l3-and-ipmc	more l2
L3 Hash IPv4 Unicast	40K	56K	16K
L3 Hash IPv6 Unicast	24K	32K	8K
Next Hop	32K	32K	32K
Internal IPv4 LPM	12K	12K	12K
Internal IPv6 LPM	6K	6K	6K
IPv4 hosts with min LPM routes (assumes 75% utilization of L3 hash table)	38K	50K	24K
IPv4 hosts with max LPM routes (assumes 75% utilization of L3 hash table)	30K	42K	12K
Remote IPv4 Host Entries (assumes 75% utilization of L3 hash table)	48K	72K	24K
IPv6 Host Entries (assumes 75% utilization of L3 hash table)	18K	24K	6K
IP multicast groups	4K	4K	4K
IP-multicast (s,v,g) entries (will depend on hash utilization)	24K	40K	8K

The BlackDiamond X8-100G4X switch has the following configurable internal tables:

BlackDiamond X8-100G4X Hardware Routing Table Configuration Capacities for Platforms with Configurable L2/L3 Internal Tables

L3 Characteristic	l2-and-l3	more l3-and-ipmc	more l2
L3 Hash IPv4 Unicast	160K	224K	96K
L3 Hash IPv6 Unicast	64K	64K	48K
Next Hop	64K	64K	64K
Internal IPv4 LPM	16K	16K	16K
Internal IPv6 LPM	8K	8K	8K
IPv4 hosts with min LPM routes (assumes 75% utilization of L3 hash table)	130K	178K	64K
IPv4 hosts with max LPM routes (assumes 75% utilization of L3 hash table)	120K	168K	72K
Remote IPv4 Host Entries (assumes 75% utilization of L3 hash table)	208K	304K	88K
IPv6 Host Entries (assumes 75% utilization of L3 hash table)	48K	48K	36K
IP multicast groups	16K	16K	16K
IP-multicast (s,v,g) entries (will depend on hash utilization)	64K	64K	16K

In addition to configuring the number of reserved entries in the LPM tables, the configure iproute reserved-entries command configures which entries are stored in which tables. The following table shows the hardware routing table contents for several configurations.

Hardware Routing Table Contents

Table	All platforms except BlackDiamond 8900 xl- Series Modules and Summit X480 Switches	BlackDiamond 8900 xl-Series Modules and Summit X480 Switches, Maximum IPv4 Capacity Configuration	BlackDiamond 8900 xl-Series Modules and Summit X480 Switches, Maximum IPv6 Capacity Configuration	BlackDiamond 8900 xl-Series Modules and Summit X480 Switches, Default Configuration
Internal LPM—Reserved space	Entries for IPv4 and IPv6 routes.	Entries for IPv6 routes.^d	Entries for IPv4 routes.	Entries for IPv6 routes.
Internal LPM—Unreserved space	Entries for IPv4 local and remote hosts.	N/A^e	Entries for IPv4 local and remote hosts.	N/A
External LPM—Reserved space	N/A	Entries for IPv4 routes.	N/A	Entries for IPv4 routes.
External LPM—Unreserved space	N/A	Entries for IPv4 local and remote hosts.	Entries for IPv6 routes.	Entries for IPv4 local and remote hosts.
L3 Hash	Entries for IPv4 local and remote hosts, IPv4 and IPv6 multicast entries, and IPv6 local hosts.a	Entries for IPv4 local and remote hosts, IPv4 and IPv6 multicast entries, and IPv6 local hosts.	Entries for IPv4 local and remote hosts, and IPv4 and IPv6 multicast entries.	IPv4 and IPv6 multicast entries, and IPv6 local hosts
Next Hop	MAC address and egress port information for the entries in the LPM and L3 Hash tables.	MAC address and egress port information for the entries in the LPM and L3 Hash tables.	MAC address and egress port information for the entries in the LPM and L3 Hash tables.	MAC address and egress port information for the entries in the LPM and L3 Hash tables.

^{d IPv6 routes and hosts consume two
entries.}

^{e In this configuration, all space in the internal LPM table is
reserved for IPv6 routes.}

Published March 2020prev | next

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