Nokia 7210 Configuration Manual page 569

7210 SAS-M, T, R6, R12, Mxp, Sx, S Basic System
Configuration Guide
Note: (Continued)
3HE 17358 AAAB TQZZA
• On the 7210 SAS-R6 and 7210 SAS-R12 IMMv2 card, 7210 SAS-Sx/S 1/10GE
(standalone and standalone-VC), and 7210 SAS-Mxp, a pool of 4K IPv4 entries are
allocated on system bootup primarily for use by about 256 /128-bit IPv6 addresses.
The remaining entries can be shared with IPv4 prefix, if IPv6 is not enabled on the
node. That is, without IPv6 enabled on the node, the maximum number of IPv4 prefixes
possible is equal to the maximum size of the route table supported for the platform,
reduced by 1K entries. The 1K entries correspond to those reserved by the system for
allocation to IPv6 /128-bit addresses.
Note that the maximum number of IPv4 prefixes includes the amount of addresses
allocated for directly connected IP subnets (the user has an option to reserve the
amount required for directly connected IPv4 subnets by configuring the
command) and IPv4 routes statically configured on the node or learned dynamically
using a routing protocol.
For example, if the maximum size of the route table supported on the node is 32K, the
total number of IPv4 prefixes (including both directly connected subnets and routes
statically configured or dynamically learned using a routing protocol) is 31K (the 1K
route entries are used to allocate up to 256 /128-bit IPv6 addresses). The maximum
size of the route table quoted in the example is for illustration purposes only.
• On the 7210 SAS-R6 and 7210 SAS-R12 IMMv2 card, 7210 SAS-Sx/S 1/10GE
(standalone and standalone-VC), and 7210 SAS-Mxp, the maximum number of IPv4
prefixes possible with IPv6 /64-bit routes configured is equal to the maximum size that
the route table supports for the platform, reduced by the sum of the number of routes
configured for IPv6 /64-bit prefixes and an amount of 4K entries (reserved for /128-bit
IPv6 addresses). The user has an option to reserve resources used for IPv6 /64-bit
prefix using the max-ipv6-routes command. When max-ipv6-routes is configured
using a value greater than zero, the IPv4 prefixes can no longer use the space
reserved for IPv6 /128-bit addresses. The software enforces the maximum number of
IPv6 prefixes possible as less than the max-ipv6-routes value.
Using the preceding example, if the maximum size of the route table supported on the
node is 32K, total number of IPv4 prefixes (only dynamically learned ones using a
routing protocol) is about 25K, assuming max-ipv6-routes is set to 1000 and max-ip-
subnets is set to 1000. That is, 32K – (4K + 2 * 1K + 1K) = 25K (recollect each IPv6 /
64-bit route entry requires twice the space of IPv4 route entry). The maximum size of
the route table quoted in the example is for illustration purposes only.
• On the 7210 SAS-R6 and 7210 SAS-R12 IMMv2 card, 7210 SAS-Sx/S 1/10GE
(standalone and standalone-VC), 7210 SAS-Sx 10/100GE, and 7210 SAS-Mxp, the
maximum number of IPv6 /64-bit routes is equal to the number of routes configured
using the max-ipv6-routes command.
Using the preceding example, if the maximum size of the route table supported on the
node is 32K, maximum number of IPv6 /64-bit prefixes (including only dynamically
learned ones, using a routing protocol) is about 13500, assuming max-ipv6-routes is
set to 13K and max-ip-subnets is set to 1000. The number of IPv4 routes allowed is
zero (32K – (4K + 2 * 13500 + 1K) = 0 (recollect each IPv6 /64-bit route entry requires
twice the space of IPv4 route entry). The maximum size of the route table quoted in the
example is for illustration purposes only.
Use subject to Terms available at: www.nokia.com
© 2021 Nokia.
System Management
max-ip-subnets
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