HP-UX TCP/IP Performance White Paper, March 2008

possible that IPv6 will assemble a packet with fragments from different

packets. In this case, the problem will be detected only if the upper-

layer is validating data integrity (using checksums).

The fragment identifier field in IPv6 is 32 bits, allowing a much larger

range of values than the 16-bit field in IPv4, and greatly reducing the

possibility of wrap within the reassembly timeout interval. With Gigabit

Ethernet link, IPv6 fragment identifiers may wrap within approximately

52000 seconds. With a 10 Gigabit Ethernet link, IPv6 fragment identifiers

may wrap within 5200 seconds. [100, - ] Default: 60000 (60 seconds)

ip6_icmp_interval:

Limit the bandwidth and forwarding costs incurred sending ICMPv6

error messages. This situation may occur when a source sending a

stream of erroneous packets fails to heed the resulting ICMPv6

error messages. [0, 10000] Default: 100ms

This tunable limits the rate of ICMPv6 error messages that the kernel generates.

ip6_ill_status:

Displays a report of all IPv6 allocated physical interfaces.

This will display interfaces IPv6 believes to be "physical" -

basically the ":0" interfaces such as lan0:0, which is the same

as lan0.

This will display interfaces IPv6 believes to be "physical" - basically, the ":0" interfaces (see the manpage

for ifconfig(1m) for more) such as lan0:0, which is the same as lan0. However, that may not actually

be true physical interface - it could be a virtual interface created by Auto Port Aggregation (APA). Since

link trunking is done without the knowledge of IPv6, IPv6 cannot, nor does it need to, distinguish between a

"true" physical interface and a virtual interface created through trunking.

ip6_ipif_status:

Displays a report of all allocated logical interfaces.

A logical interface is created whenever one adds IPv6 addresses to the one already assigned to a

"physical" interface or via IPv6 auto-configuration mechanism. These are also sometimes referred to as

aliased addresses and are given names such as lan0:1, lan0:2 and so on. These exist only at the IPv6

level; neither the NIC driver or DLPI knows of its existence. While a physical/virtual interface (see the

discussion of ip6_ill_status) will appear in the output of lanscan(1M), a logical interface will not.

ip6_ire_cleanup_interval:

Sets the time-out interval for purging IPv6 routing table entries.

All entries unused for this period of time are deleted.

[5000, - ] Default: 300000 (5 minutes)

Host routes associated with the IRE6_ROUTE flag from the ndd –get /dev/ip6 ip6_ire_status

output will be deleted. A host route with the IRE6_ROUTE flag must exist for any non-local destination

before an IPv6 datagram can be sent to that address. The IRE6_ROUTE host routes are created internally