Digital Data Communications LevelOne GTL-2091 User manual

IPv6 Configuration
(GTL-2091)
V1.0

Digital Data Communications GmbH.
http://www.level1.com

Table of Contents
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Table of Contents
Chapter 1 IPv6 Protocol’s Configuration...............................................................................................................................1
1.1 IPv6 Protocol’s Configuration ................................................................................................................................1
1.2 Enabling IPv6.........................................................................................................................................................1
1.2.1 Setting the IPv6 Address ...........................................................................................................................1
Chapter 2 Setting the IPv6 Services.....................................................................................................................................3
2.1 Setting the IPv6 Services.......................................................................................................................................3
2.1.1 Managing the IPv6 Link.............................................................................................................................3

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IPv6 Configuration
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Chapter 1 IPv6 Protocol’s Configuration
1.1 IPv6 Protocol’s Configuration
The configuration of the IPv6 address of the router only takes effect on the VLAN
interface, not on the physical interface.
The IPv6 protocol is disabled in default state. If the IPv6 protocol need be used on
a VLAN interface, this protocol should be first enabled in VLAN interface
configuration mode. To enable the IPv6 protocol, users have to set the IPv6
address. If on a VLAN interface at least one IPv6 address is set, the VLAN
interface can handle the IPv6 packets and communicates with other IPv6 devices.
To e n abl e th e IPv 6 pr o toc o l , u s ers sho u ld f i nis h the fol l o wi n g ta s k:
l Setting at least one IPv6 address in VLAN interface configuration mode
1.2 Enabling IPv6
1.2.1 Setting the IPv6 Address
The IPv6 address is used to determine the destination address to which the IPv6
packets can be sent. There are three kinds of IPv6 addresses.
Kind
Referred Format
Remarks
Unicast
address
2001:0:0:0:0DB8:800:2
00C:417A/64
2001:0:0:0:0DB8:800:200
C:417A stands for a unicast
address, while 64 stands
for the length of the prefix
of this address.
Multicast
address
FF01:0:0:0:0:0:0:101
All multicast addresses
begin with FF.
Any address
2002:0:0:0:0DB8:800:2
00C:417A/64
The format of this address
is the same as that of the
unicast address. Different
VLAN interfaces can be set
to have the same address,
no matter it is a
unicast/broadcast/multicast
address.
For the further details of the IPv6 address, see RFC 4291.
In order to enable IPv6, users must set a unicast address in VLAN interface
configuration mode. The set unicast address must be one or multiple addresses of
the following type:

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IPv6 Configuration
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l IPv6 link-local address
l Global IPv6 address
To se t an IPv 6 li n k-local address in VLAN interface configuration mode, run the
following commands.
Command
Purpose
ipv6 enable
Sets a link-local
address
automatically.
ipv6 address
fe80::x link-local
Sets a link-local
address
manually.
Note:
l The link-local address must begin with fe80. The default length of the prefix is 64 bit. At
manual settings only the values at the last 64 bits can be designated.
l On a VLAN interface can only one link-local address be set.
l After IPv6 is enabled through the configuration of the link-local address, IPv6 only takes
effect on the local link.
To set a g l oba l I Pv6 a d dre s s i n VLAN interface configuration mode, run the
following commands.
Command
Purpose
ipv6 address autoconfig
Sets a global
address
automatically.
ipv6 address [ipv6-address/prefix-length |
prefix-name sub-bits/prefix-length] | [eui-64]
Sets a global
address.
ipv6 address X:X:X:X::X/<0-128> anycast
Sets an address
of
unicast/broadca
st/multicast.
Note:
l When IPv6 is enabled through the configuration of a global address, all interconnected
IPv6 device can be handled by IPv6.
l If a link-local address has not been set before the configuration of the global address, the
system will set a link-local address automatically.

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IPv6 Configuration
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Chapter 2 Setting the IPv6 Services
2.1 Setting the IPv6 Services
After IPv6 is enabled, all services provided by IPv6 can be set. The configurable
IPv6 service is shown below:
(1) Managing the IPv6 Link
2.1.1 Managing the IPv6 Link
IPv6 provides a series of services to control and manage the IPv6 link. This series
of services includes:
(1) Setting the transmission frequency of the ICMPv6 packet
(2) Setting the source IPv6 route
(3) Setting the MTU of IPv6
(4) Setting IPv6 redirection
(5) Setting IPv6 destination unreachablity
(6) Setting IPv6 ACL
(7) Setting IPv6 Hop-Limit
1. Setting the transmission frequency of the ICMPv6 packet
If you want to limit the transmission frequency of the ICMPv6 packet, run the command in
the following table. If the ICMPv6 transmission frequency is larger than the set value, the
transmission frequency will be limited.
The default transmission frequency is 1000us. If you want to modify the transmission
frequency, run the following command in global mode:
Command
Purpose
ipv6 icmp6-ratelimit ratelimit
Sets the transmission
frequency of the ICMPv6
packet.
2. Setting the source IPv6 route
IPv6 allows a host to designate the route of an IPv6 network, that is, the source route.
The host can realize the source route through using the routing header in the IPv6

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IPv6 Configuration
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packets. The router can forward packets according to the routing header, or desert this
kind of packets considering security.
The router supports the source route by default. If the source route is closed, users can
run the following command in global configuration mode to open the source route.
Command
Purpose
ipv6 source-route
Allows the source IPv6 route.
3. Setting the MTU of IPv6
All interfaces have a default IPv6 MTU. If the length of an IPv6 packet exceeds MTU,
the router will fragment this IPv6 packet.
To set I P v6 MT U o n a spe c ifi c i n ter f ace , r u n the f o llo w i ng c o mma n d in int e rfa c e
configuration mode:
Command
Purpose
ipv6 mtu bytes
Sets IPv6 MTU on an interface.
4. Setting IPv6 redirection
Sometimes, the route selected by the host is not the best one. In this case, when a switch
receives a packet from this route, the switch will transmit, according to the routing table,
the packet from the interface where the packet is received, and forward it to another
router which belongs to the same network segment with the host. Under this condition,
the switch will notify the source host of sending the packets with the same destination
address to another router directly, not by way of the switch itself. The redirection packet
demands the source host to replace the original route with the more direct route contained
in the redirection packet. The operating system of many hosts will add a host route to the
routing table. However, the switch more trusts the information getting from the routing
protocol and so the host route will not be added according to this information.
IPv6 redirection is opened by default. However, if a hot standby router protocol is
configured on an interface, IPv6 redirection is automatically closed. If the hot standby
router protocol is canceled, this function will not automatically opened.
To o p en I Pv6 r ed i r ect i on, r un t he f o llo w ing com man d :
Command
Purpose
ipv6 redirects
Allows IPv6 to transmit the
redirection packets.
5. Setting IPv6 destination unreachablity
In many cases, the system will automatically transmit the destination-unreachable packets.
Users can close this function. If this function is closed, the system will not transmit the
ICMP unreachable packets.
To e n abl e th i s fu n cti o n , r u n t h e fo l low i ng c o mm a nd:

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IPv6 Configuration
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Command
Purpose
ipv6 unreachables
Allows IPv6 to transmit the
destination unreachable
packets.
6. Setting IPv6 ACL
Users can use ACL to control the reception and transmission of packets on a VLAN
interface. If you introduce ACL on a VLAN interface in global configuration mode and
designate the filtration's direction, the IPv6 packets will be filtered on this VLAN interface.
To f i l ter the I Pv6 pac k ets , ru n the fol l o wi n g co m ma n d i n int e rfa c e configuration mode.
Command
Purpose
ipv6 traffic-filter WORD { in |
out }
Filters the IPv6 packets in the
reception or transmission
direction (in: receive; out:
transmit) on a VLAN interface.
7. Setting IPv6 Hop-Limit
Users can designate a router to transmit the value of the hop-limit field in the packets
(except those forwarded packets). All those packets that this router transmits out, if the
upper-level application does not apparently designate a hop-limit value, use the set value
of hop-limit. At the same time, the value of the hop-limit field is added to the RA packets
that this router transmits.
The default hop-limit value is 64. If you want to change this value, you can run the
following command in interface configuration mode.
Command
Purpose
ipv6 cur-hoplimit value
Designates a router to transmit the
hop-limit field of the packets.