[LARTC] Aliases and Multipath

[Jose Luis Domingo Lopez]

On Thursday, 04 December 2003, at 11:06:58 -0400,
Guillermo Gomez wrote:

> Does anyone know if i can use ethernet aliases like eth0:1 in advanced
> routing like multipath routing in order to avoid to have nxEthernet
> interfaces in my Linux box.
> 
I think it is always better to think "in ip terms" instead of "in
ifconfig terms" with respect to multiple IP addresses assigned to the
same network interface.

I don't know exactly for "ifconfig", but the syntax for "ip address"
states clearly what seems to be happening behind the scenes:
# ip address add 172.16.1.1/24 broad + dev eth1
# ip address add 172.16.2.1/24 broad + dev eth1
# ip address add 172.16.3.1/24 broad + dev eth1

So what you are doing is assigning several IP to the same physical
interface, and you deal just with IP, anything else.
# ip address show dev eth1
2: eth1: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 00:05:1c:09:f2:14 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.12/24 brd 192.168.1.255 scope global eth0
    inet 172.16.1.1/24 brd 172.16.1.255 scope global eth0
    inet 172.16.2.1/24 brd 172.16.2.255 scope global eth0
    inet 172.16.3.1/24 brd 172.16.3.255 scope global eth0

Greetings.

-- 
Jose Luis Domingo Lopez
Linux Registered User #189436     Debian Linux Sid (Linux 2.6.0-test10-mm1)