Brocade Virtual ADX Switch and Router Guide (Supporting ADX v03.1.00) - Manual (Page 76)

62 Brocade Virtual ADX Switch and Router Guide
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Configuring IP parameters
4
Specifying a single source interface for Telnet,
TACACS/TACACS+, or RADIUS packets
When the Layer 3 Switch originates a Telnet, TACACS/TACACS+, or RADIUS packet, the source
address of the packet is the lowest-numbered IP address on the interface that sends the packet.
You can configure the Layer 3 Switch to always the lowest-numbered IP address on a specific
interface as the source addresses for these types of packets. When you configure the Layer 3
Switch to use a single source interface for all Telnet, TACACS/TACACS+, or RADIUS packets, the
Layer 3 Switch uses the same IP address as the source for all packets of the specified type,
regardless of the port(s) that actually sends the packets.
Identifying a single source IP address for Telnet, TACACS/TACACS+, or RADIUS packets provides the
following benefits:
• If your Telnet, TACACS/TACACS+, or RADIUS server is configured to accept packets only from
specific IP addresses, you can use this feature to simplify configuration of the server by
configuring the Brocade device to always send the packets from the same link or source
address.
• If you specify a loopback interface as the single source for Telnet, TACACS/TACACS+, or RADIUS
packets, servers can receive the packets regardless of the states of individual links. Thus, if a
link to the server becomes unavailable but the client or server can be reached through another
link, the client or server still receives the packets, and the packets still have the source IP
address of the loopback interface.
The software contains separate CLI commands for specifying the source interface for Telnet,
TACACS/TACACS+, or RADIUS packets. You can configure a source interface for one or more of
these types of packets separately.
To specify an Ethernet or a loopback or virtual interface as the source for all TACACS/TACACS+
packets from the device, use the following CLI method. The software uses the lowest-numbered IP
address configured on the port or interface as the source IP address for TACACS/TACACS+ packets
originated by the device.
The following sections show the syntax for specifying a single source IP address for Telnet,
TACACS/TACACS+, and RADIUS packets.
Telnet packets
To specify the lowest-numbered IP address configured on a virtual interface as the device’s source
for all Telnet packets, enter commands such as the following.
Virtual ADX(config)# int loopback 2
Virtual ADX(config-lbif-2)# ip address 10.0.0.2/24
Virtual ADX(config-lbif-2)# exit
Virtual ADX(config)# ip telnet source-interface loopback 2
The commands in this example configure loopback interface 2, assign IP address 10.0.0.2/24 to
the interface, then designate the interface as the source for all Telnet packets from the Virtual ADX.
Syntax: ip telnet source-interface ethernet portnum | loopback num | ve num
The num parameter is a loopback interface or virtual interface number. If you specify an Ethernet
port, the portnum is the port’s number.
The following commands configure an IP interface on an Ethernet port and designate the address
port as the source for all Telnet packets from the Virtual ADX.