Brocade Communications Systems Layer 3 Routing Configuration ICX 6650 - Manual (Page 39)

Brocade ICX 6650 Layer 3 Routing Configuration Guide 21
53-1002603-01
Configuring IP parameters – Layer 3 Switches
NOTE
All physical IP interfaces on Brocade Layer 3 devices share the same MAC address. For this reason,
if more than one connection is made between two devices, one of which is a Brocade Layer 3 device,
Brocade recommends the use of virtual interfaces. It is not recommended to connect two or more
physical IP interfaces between two routers.
Assigning an IP address to a loopback interface
Loopback interfaces are always up, regardless of the states of physical interfaces. They can add
stability to the network because they are not subject to route flap problems that can occur due to
unstable links between a Layer 3 Switch and other devices. You can configure up to eight loopback
interfaces on a Chassis Layer 3 Switch .
You can add up to 24 IP addresses to each loopback interface.
NOTE
If you configure the Brocade Layer 3 Switch to use a loopback interface to communicate with a BGP4
neighbor, you also must configure a loopback interface on the neighbor and configure the neighbor
to use that loopback interface to communicate with the Brocade Layer 3 Switch. Refer to
“Adding a
loopback interface” on page 292.
To add a loopback interface, enter commands such as those shown in the following example.
Brocade(config-bgp-router)# exit
Brocade(config)# interface loopback 1
Brocade(config-lbif-1)# ip address 10.0.0.1/24
Syntax: interface loopback num
The num parameter specifies the virtual interface number. You can specify from 1 to the maximum
number of virtual interfaces supported on the device. To display the maximum number of virtual
interfaces supported on the device, enter the show default values command. The maximum is
listed in the System Parameters section, in the Current column of the virtual-interface row.
Refer to the syntax description in “Assigning an IP address to an Ethernet port” on page 20.
Assigning an IP address to a virtual interface
A virtual interface is a logical port associated with a Layer 3 Virtual LAN (VLAN) configured on a
Layer 3 Switch. You can configure routing parameters on the virtual interface to enable the Layer 3
Switch to route protocol traffic from one Layer 3 VLAN to the other, without using an external
router.
1
You can configure IP routing interface parameters on a virtual interface. This section describes how
to configure an IP address on a virtual interface. Other sections in this chapter that describe how to
configure interface parameters also apply to virtual interfaces.
NOTE
The Layer 3 Switch uses the lowest MAC address on the device (the MAC address of port 1 or 1/1/1)
as the MAC address for all ports within all virtual interfaces you configure on the device.
To add a virtual interface to a VLAN and configure an IP address on the interface, enter commands
such as the following.
1. The Brocade feature that allows routing between VLANs within the same device, without the
need for external routers, is called Integrated Switch Routing (ISR).