3Com Switch 8800 Advanced Software V5 Configuration Guide

228 CHAPTER 23: IPV6 BASICS CONFIGURATION
Configuring IPv6
FIB-Based Forwarding
With the caching function of IPv6 FIB enabled, the device searches the FIB cache
when forwarding packets, thus reducing the time in searching IP packets and
improving the forwarding efficiency.
In the load sharing mode of IPv6 FIB, the device can decide how to select an equal
cost multi-path (ECMP) route to forward packets. Currently, two load sharing
modes are supported:
■ Load sharing based on the HASH algorithm: A certain algorithm based on the
source IPv6 address and destination IPv6 address is adopted to select an ECMP
route to forward packets.
■ Load sharing based on polling: Each ECMP route is used in turn to forward
packets.
Follow these steps to configure the IPv6 FIB-based forwarding:
Configuring Capacity
and Update Period of
Token Bucket
If too many ICMPv6 error packets are sent within a short time in a network,
network congestion may occur. To avoid network congestion, you can control the
maximum number of ICMPv6 error packets sent within a specified time, currently
by adopting the token bucket algorithm.
You can set the capacity of a token bucket, namely, the number of tokens in the
bucket. In addition, you can set the update period of the token bucket, namely,
the interval for updating the number of tokens in the token bucket to the
configured capacity. One token allows one ICMPv6 error packet to be sent. Each
time an ICMPv6 error packet is sent, the number of tokens in a token bucket
decreases by 1. If the number of ICMPv6 error packets successively sent exceeds
the capacity of the token bucket, subsequent ICMPv6 error packets cannot be sent
out until the number of tokens in the token bucket is updated and new tokens are
added to the bucket.
Follow these steps to configure the capacity and update period of the token
bucket:
To do... Use the command... Remarks
Enter system view system-view -
Enable the caching function of IPv6
FIB
ipv6 fibcache {
slot-number | all }
Required
Disabled by default
Configure
the IPv6 FIB
load sharing
mode
Configure the load
sharing based on the
HASH algorithm
ipv6
fib-loadbalance-type
hash-based
Optional
By default, the load sharing
based on polling is
adopted, that is, each
ECMP route is used in turn
to forward packets.
Configure the load
sharing based on
polling
undo ipv6
fib-loadbalance-type
hash-based
To do... Use the command... Remarks
Enter system view system-view -