Brocade Communications Systems Layer 3 Routing Configuration ICX 6650 - Manual (Page 41)

Brocade ICX 6650 Layer 3 Routing Configuration Guide 23
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Configuring IP parameters – Layer 3 Switches
For number, enter the ID of the virtual routing interface.
Use the no form of the command to disable the configuration.
Virtual routing interface 2 and 3 do not have their own IP subnet addresses, but are sharing the IP
address of virtual routing interface 1.
Deleting an IP address
To delete an IP address, enter the no ip address command.
Brocade(config-if-e10000-1/1/1)# no ip address 10.1.2.1
This command deletes IP address 10.1.2.1. You do not need to enter the subnet mask.
To delete all IP addresses from an interface, enter the no ip address * command.
Brocade(config-if-e10000-1/1/1)# no ip address *
Syntax: no ip address ip-addr | *
Configuring 31-bit subnet masks on
point-to-point networks
To conserve IPv4 address space, a 31-bit subnet mask can be assigned to point-to-point networks.
Support for an IPv4 address with a 31-bit subnet mask is described in RFC 3021.
With IPv4, four IP addresses with a 30-bit subnet mask are allocated on point-to-point networks. In
contrast, a 31-bit subnet mask uses only two IP addresses: all zero bits and all one bits in the host
portion of the IP address. The two IP addresses are interpreted as host addresses, and do not
require broadcast support because any packet that is transmitted by one host is always received by
the other host at the receiving end. Therefore, directed broadcast on a point-to-point interface is
eliminated.
IP-directed broadcast CLI configuration at the global level, or the per interface level, is not
applicable on interfaces configured with a 31-bit subnet mask IP address.
When the 31-bit subnet mask address is configured on a point-to-point link, using network
addresses for broadcast purposes is not allowed. For example, in an IPV4 broadcast scheme, the
following subnets can be configured:
• 10.10.10.1 - Subnet for directed broadcast: {, -1}
• 10.10.10.0 - Subnet for network address: {, 0}
In a point-to-point link with a 31-bit subnet mask, the previous two addresses are interpreted as
host addresses and packets are not rebroadcast.
Configuring an IPv4 address with a 31-bit subnet mask
To configure an IPv4 address with a 31-bit subnet mask, enter the following commands.
You can configure an IPv4 address with a 31-bit subnet mask on any interface (for example,
Ethernet, loopback, VE, or tunnel interfaces).
Brocade(config)# interface ethernet 1/1/5
Brocade(config-if-e10000-1/1/5)# ip address 10.10.9.9 255.255.255.254