BigIron RX Series Configuration Guide 18153-1001986-01Specifying a single source interface for Telnet, TACACS, TACACS+, or RADIUS packets 7NOTEIf you change the router ID, all current BGP4 sessions are cleared.By default, the router ID on a device is one of the following:• If the router has loopback interfaces, the default router ID is the IP address configured on thelowest numbered loopback interface configured on the device. For example, if you configureloopback interfaces 1, 2, and 3 as follows, the default router ID is 9.9.9.9/24:• Loopback interface 1, 9.9.9.9/24• Loopback interface 2, 4.4.4.4/24• Loopback interface 3, 1.1.1.1/24• If the device does not have any loopback interfaces, the default router ID is the lowestnumbered IP interface configured on the device.If you prefer, you can explicitly set the router ID to any valid IP address. The IP address cannot be inuse on another device in the network.NOTEThe device uses the same router ID for both OSPF and BGP4. If the router is already configured forOSPF, you may want to use the router ID that is already in use on the router rather than set a newone. To display the router ID, enter the show ip CLI command at any CLI level.To change the router ID, enter a command such as the following.BigIron RX(config)# ip router-id 209.157.22.26Syntax: ip router-id The can be any valid, unique IP address.NOTEYou can specify an IP address used for an interface, but do not specify an IP address in use byanother device.Specifying a single source interface for Telnet, TACACS,TACACS+, or RADIUS packetsWhen the device originates a Telnet, TACACS, TACACS+, or RADIUS packet, the source address ofthe packet is the lowest-numbered IP address on the interface that sends the packet. You canconfigure the device to always use the lowest-numbered IP address on a specific interface as thesource addresses for these types of packets. When you configure the device to use a single sourceinterface for all Telnet, TACACS, TACACS+, or RADIUS packets, the device uses the same IP addressas the source for all packets of the specified type, regardless of the ports that actually sends thepackets.Identifying a single source IP address for Telnet, TACACS, TACACS+, or RADIUS packets provides thefollowing benefits:• If your Telnet, TACACS, TACACS+, or RADIUS server is configured to accept packets only fromspecific IP addresses, you can use this feature to simplify configuration of the server byconfiguring the Brocade device to always send the packets from the same link or sourceaddress.
