FAQ5: How to use smitty to add a 2nd IP address & Network?
nagger 100000MRSJ Visits (10418)
Most AIX system administrators use: smitty tcpip to add a hostname, IP address, network mask, gateway and DNS server setting to get the virtual machines (LPAR) and AIX on a network. And as a side benefit so we don't need to use the ghastly VTERM console any more as ssh or the dreaded unsecure telnet (just don't do it) can now be used - as the root user:
# smitty tcpip ... Minimum Configuration & Startup Further Configuration Use DHCP for TCPIP Configuration & Startup IPV6 Configuration Quality of Service Configuration & Startup Configure IP Security (IPv4) Configure IP Security (IPv6)
Once smitty starts, you take the "Minimum Configuration & Startup" first line menu option then select the Network interface like en0, en1 etc.
That sets up the primary network for the machine and the hostname matches the DNS server name for the IP address.
* HOSTNAME [ora
But lots of machines in production have many networks for various purposes like backup, admin network, user access and clustering.
So how to set up these 2nd, 3rd, 4th etc. Network interfaces is not so obvious.
Again start with: smitty tcpip
$ smitty tcpip ... Minimum Configuration & Startup Further Configuration Use DHCP for TCPIP Configuration & Startup IPV6 Configuration Quality of Service Configuration & Startup Configure IP Security (IPv4) Configure IP Security (IPv6)
Then the second option "Further Configuration"
Hostname Static Routes Network Interfaces Name Resolution Client Network Services Server Network Services Manage Print Server Select BSD style rc Configuration Start Configured TCPIP Daemons Stop TCPIP Daemons Authentication Configuration
then down two to "Network Interfaces"
Network Interface Selection Network Interface Drivers
then "Network Interface Selection"
List All Network Interfaces Add a Network Interface Change / Show Characteristics of a Network Interface Remove a Network Interface PVCs for IP over an ATM Network Configure Aliases
then "Change / Show Characteristics of a Network Interface"
then select the Network interface like en0, en1 but making sure you DO NOT select the primary network interface that you set above.
Network Interface Name en1 INTERNET ADDRESS (dotted decimal) [126.96.36.199] Network MASK (hexadecimal or dotted decimal) [255.255.255.0] Current STATE up + Use Address Resolution Protocol (ARP)? yes + BROADCAST ADDRESS (dotted decimal)  Interface Specific Network Options ('NULL' will unset the option) rfc1323  tcp_mssdflt  tcp_nodelay  tcp_recvspace  tcp_sendspace  Apply change to DATABASE only no +
This gives you a simpler panel to fill in but NOT the hostname, gateway nor he DNS - these are only set once and while you are setting up the primary network as they will apply to the other networks too.
Using the "Minimum Configuration & Startup" panel to set up the 2nd, 3rd etc network interfaces is a VERY BAD IDEA as it messes up the network configuration but I have seen it done many times.
*** FLAME ON ***
Before I get lots of comments about why does smitty let you do this if it causes problems, I would just like to say UNIX, AIX and smitty are not meant to be "idiot proof" and I like it just the way it is. Idiots, newbies to UNIX and the untrained should not be given root access.
*** FLAME OFF ***
Cheers, Nigel Griffiths