Brocade ICX 6650 Administration Guide 137
53-1002600-01
Static neighbor entries configuration 5
For a virtual routing interface, the maximum value of the MTU is the maximum frame size
configured for the VLAN to which it is associated, minus 18 (Layer 2 MAC header + CRC). If
a maximum frame size for a VLAN is not configured, then configure the MTU based on the
smallest maximum frame size of all the ports of the VLAN that corresponds to the virtual
routing interface, minus 18 (Layer 2 MAC header + CRC).

Changing the IPv6 MTU

To define IPv6 maximum transmission unit (MTU) globally, enter the ipv6 mtu command at the
Global CONFIG level of the CLI:
Brocade(config)#ipv6 mtu 1300
You can configure the IPv6 MTU on individual interfaces. For example, to configure the MTU on
Ethernet interface 1/2/1 as 1280 bytes, enter the following commands.
Brocade(config)#interface ethernet 1/1/1
Brocade(config-if-e10000-1/1/1)#ipv6 mtu 1280
Syntax: [no] ipv6 mtu <bytes>
For <bytes>, specify a value between 1280 – 1500, or 1280 – 10200 if jumbo mode is enabled. If
a nondefault value is configured for an interface, router advertisements include an MTU option.
Static neighbor entries configuration
In some special cases, a neighbor cannot be reached using the neighbor discovery feature. In this
situation, you can add a static entry to the IPv6 neighbor discovery cache, which causes a neighbor
to be reachable at all times without using neighbor discovery. (A static entry in the IPv6 neighbor
discovery cache functions like a static ARP entry in IPv4.)
NOTE
A port that has a statically assigned IPv6 entry cannot be added to a VLAN.
NOTE
Static neighbor configurations will be cleared on secondary ports when a trunk is formed.
For example, to add a static entry for a neighbor with the IPv6 address 2001:DB8:2678:47b and
link-layer address 2001.DB8.8641 that is reachable through Ethernet interface 1/1/1, enter the
ipv6 neighbor command.
Brocade(config)#ipv6 neighbor 2001:DB8:2678:47b ethernet 1/1/1 2001.DB8.8641
Syntax: [no] ipv6 neighbor <ipv6-address> ethernet <stack-unit>/<slot>/<port>| ve
<ve-number> [ethernet <stack-unit>/<slot>/<port>] <link-layer-address>
The <ipv6-address> parameter specifies the address of the neighbor.
The ethernet | ve parameter specifies the interface through which to reach a neighbor. Specify the
Ethernet port in the <stack-unit>/<slot>/<port> format. Stack-unit is 1. If you specify a VE, specify
the VE number and then the Ethernet port numbers associated with the VE. The link-layer address
is a 48-bit hardware address of the neighbor.