IP CLI Commands
2/1553-ZAT 759 94 Uen B – December 2005
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12.59
ip interface add secondaryipaddress
12.59.1 Syntax
ip interface {<name>|<number>} add secondaryipaddress
<ipaddress> [<netmask>]
12.59.2 Description
This command adds a secondary IP address to an existing IP interface. A
secondary address may be used to create an extra IP address on an interface
for management purposes, or to allow the IP stack to route between two
subnets on the same interface.
The functionality of secondary IP addresses depends on several parameters
including the type of IP interface and the netmask:
•
If a secondary address is on the
same
subnet as the primary interface
address, you do not need to specify a subnet mask for that secondary
address. This applies to all interface types.
•
If a secondary address is on a
different
subnet to the primary address,
and the interface is Ethernet or a transport using a bridged encapsulation,
you must specify the subnet mask. The IP stack will listen on the new
address for connections to local services (e.g., for management
purposes), and will also route packets to the new subnet.
•
If a secondary address is on a
different
subnet to the primary address,
and the interface is a point-to-point interface, specifying a netmask is
optional.
−
For the same behavior as described for Ethernet interfaces above, the
subnet mask
should
be specified.
−
If the subnet mask is
not
specified, the IP address will not be
associated with any subnet, but will still be recognized as one of the
IP stack’s own addresses for local traffic.
Note:
The ability to specify a subnet mask with a secondary address is still
supported, but in ISOS 9.0, this is
superseded
by the functionality of
virtual interfaces. You should use virtual interfaces instead. Support
for adding secondary IP addresses including subnet mask
specification will be withdrawn in a future ISOS release.
