Hello,

i can activate / deactivate an interface with ifconfig.
eg:
ifconfig down eth0
ifconfig up eth0

But where does ifconfig store the information about eth0 (like ip adress) so that i can do a "ifconfig up eth0" after a "ifconfig down eth0" ?

regards

I think it can vary a bit between distros but take a look in:
/etc/sysconfig/network-scripts/

perhaps, but i don't think so because look at the content of this file:
Where sould ifconfig know the correct line for interface eth0?? What is if i will have more than only 2 interfaces??
Any idea?

# eth0
IPADDR1="192.100.1.7" # REPLACE with YOUR IP address!
NETMASK1="255.255.255.255" # REPLACE with YOUR netmask!

# eth1
IPADDR2="192.100.1.8" # REPLACE with YOUR IP address!
NETMASK2="255.255.255.255" # REPLACE with YOUR netmask!

then the config would read
# eth2
# eth3

etc,etc

thanks for your answer but:

if i shutdown eth0 + eth1:

ifconfig eth0 down
ifconfig eth1 down

and entries in my 'network config file' are:

# eth0
IPADDR1="192.100.1.7" # REPLACE with YOUR IP address!
NETMASK1="255.255.255.255" # REPLACE with YOUR netmask!

# eth1
IPADDR2="192.100.1.8" # REPLACE with YOUR IP address!
NETMASK2="255.255.255.255" # REPLACE with YOUR netmask!

An 'ifconfig eth1 up' would give 'eth1' the ip adress of 'IPADDR2'!
@ehdwuld: if you would be right, this command should give 'eth1' the ip adress of 'IPADDR1' and not of 'IPADDR2'!

please help

ok
please I donot under stand your strange customs
your question was " where is this stored "
you asked for an expert opinion
you got one
you said " I don't think so "
you you are now the expert?

hmmmm

any ways
if you had " more " interfaces on your box
it would read

# eth0
IPADDR1="192.100.1.7" # REPLACE with YOUR IP address!
NETMASK1="255.255.255.255" # REPLACE with YOUR netmask!

# eth1
IPADDR2="192.100.1.8" # REPLACE with YOUR IP address!
NETMASK2="255.255.255.255" # REPLACE with YOUR netmask!

# eth2
IPADDR3="192.100.1.9" # REPLACE with YOUR IP address!
NETMASK1="255.255.255.255" # REPLACE with YOUR netmask!

# eth3
IPADDR4="192.100.1.10" # REPLACE with YOUR IP address!
NETMASK2="255.255.255.255" # REPLACE with YOUR netmask!



please explain the part you are not understanding???


numbering of the interfaces starts at 0, 1, 2, etc......
numbering of the addresses follow conventional schemes starting at 1, 2, 3, etc........

I think what ehd is try to say is the file pulls the info from IPADDR1 and applies it to eth0. IPADDR2 would apply to eth1.

But if you have read my last reply, you would understand the problem!
that eth0 doesn't get the ip adress of IPADDR1!!!

The order of the network cards is assigned by the kernel in the order they were discovered. Look at the output from dmesg. As long as you don't move the cards around in the expansion slots, the order will always be the same.

ok, maybe i don't fully understand this drama, as i don't have to take my interfaces up and down regularly, but i see a quick solution:

write a script for restoring the interfaces so that the interfaces are labelled consistently, i.e. always put "/sbin/ifconfig eth0 <IP of eth0> broadcast <blah> netmask <blah>" BEFORE you pull up eth1.

that should work, and it might even leave the interfaces that are already up alone (i.e. not interrupt transfers through them). so instead of using "ifconfig eth1 up", link the script into your $PATH so you can issue "putemup" from the CL to put all interfaces back online.

HTH,
y-p

is the problem that it address is not
192.100.1.1
?????????

why?

if your network's
internal dhcp server sees itself first
it gets 192.100.1.1
then it see your router
it gets 192.100.1.2
then it discovers your buddies PC
it gets 192.100.1.3
and on and on
until it reaches to the ports on your box
which it labels 192.100.1.7, 192.100.1.8 , etc
its all part of the discovery protocols
read up on DHCP

maybe there you will find the answer

maybe the network block starts at something other than
192.100.1.0

in which case the range of available addresses would be different

Edit
could be the order in which they are plugged into the switch
maybe your network printer is
192.100.1.1