william_holmes
asked on
2 network cards in one server on 2 networks.
Hi,
I have three machines A, B and C; and 2 hubs.
Machine B has 2 network cards and is attached to both
hubs, Machines A 123.123.123.32 and C 192.168.255.1
are connected to different hubs respectively.
So the senario looks like.
******************
* *
* A *
* 123.123.123.32 *
* *
******************
*
*
*
***********************
* *
* B *
* 123.123.123.31 eth0 *
* 192.168.255.10 eth1 *
* *
***********************
*
*
*
******************
* *
* C *
* 192.168.255.1 *
* *
******************
I have installed Redhat 6.1 on machine B and given it
an IP address 123.123.123.31. I then ran linuxconf
and added the second ethernet device and
IP 192.168.255.10. Machines A and B can
ping each other happily. Then by swapping the IP
addresses in
/etc/sysconfig/network-scr
and
/etc/sysconfig/network-scr
and
ifconfig eth0 123.123.123.31 netmask 255.255.255.0 up
ifconfig eth1 192.168.255.10 netmask 255.255.255.0 up
and swapping the network cables on the network
devices. I can still ping A and B happily.
Figuring this proves both the network devices work.
I can not ping between machines B and C, I have tried
lots of different things but am obviously missing the
obvious.
netstat -r gives me.
Destination Gateway GenMask Flags MSS Window irtt Iface
123.123.123.0 * 255.255.255.0 U O O 0 eth1
192.168.255.0 * 255.255.255.0 U O O 0 eth0
127.0.0.0 * 255.0.0.0 U O O 0 lo
/etc/sysconfig/network
NETWORKING="yes"
FORWARD_IPV4="yes"
HOSTNAME="host.mynet.com"
GATEWAY="123.123.123.1"
GATEWAYDEV="eth0"
/etc/sysconfig/network-scr
DEVICE="eth0"
IPADDR="123.123.123.31"
NETMASK="255.255.255.0"
ONBOOT="yes"
BOOTPROTO="none"
all the ipx stuff is no.
/etc/sysconfig/network-scr
DEVICE="eth1"
IPADDR="192.168.255.10"
NETMASK="255.255.255.0"
ONBOOT="yes"
BOOTPROTO="none"
all the ipx stuff is no.
I am aiming just to be able to ping machines A and C
from machine B. Then B from A and C at this point.
I looked in linuxconf and routing is enabled.
I then deleted everything from the route table
route del -net 123.123.123.0 netmask 255.255.255.0 dev eth0
route del -net 192.168.255.0 netmask 255.255.255.0 dev eth1
So when I do netstat -r I get.
Destination Gateway GenMask Flags MSS Window irtt Iface
127.0.0.0 * 255.0.0.0 U O O 0 lo
Of course I can't ping anything now.
I add
route add -net 123.123.123.0 netmask 255.255.255.0 gw 123.123.123.31
route add -net 192.168.255.0 netmask 255.255.255.0 gw 192.168.255.10
So doing a netstat -r again I get
Destination Gateway GenMask Flags MSS Window irtt Iface
123.123.123.0 123.123.123.31 255.255.255.0 UG O O 0 eth1
192.168.255.0 192.168.255.10 255.255.255.0 UG O O 0 eth0
127.0.0.0 * 255.0.0.0 U O O 0 lo
I can pinging machine A(123.123.123.32) from machine
B(123.123.123.31 & 192.168.255.10 ) is fine.
I still can't ping machine C(192.168.255.1) from
B(123.123.123.31 & 192.168.255.10 ).
Any suggestions appreciated thanks.
William
william_holmes@rocketmail.
It's not true that 192.168.x.x addresses can't be forwarded; just that they aren't _supposed_ to be forwarded outside of your local autonomous system (which can consist of many networks). Internally, you can forward them at will, and it looks like that's what you'll want/need to do.
What type of machine is "C"? If it's Linux or NT, could you post the "ifconfig" and "netstat -rn" output for it? (I think W95/98 also has something similar, "ipconfig" or something?)
Is there anything else on the 192 hub that you can try pinging from both B and C? How about pinging the broadcast address:
"ping [-b] 192.168.255.255"
(I think recent ping commands need a "-b" option to ping the broadcast address correctly.) You should be able to see both machines, of course, but if you don't even get a response from yourself, you've got a problem.
What type of machine is "C"? If it's Linux or NT, could you post the "ifconfig" and "netstat -rn" output for it? (I think W95/98 also has something similar, "ipconfig" or something?)
Is there anything else on the 192 hub that you can try pinging from both B and C? How about pinging the broadcast address:
"ping [-b] 192.168.255.255"
(I think recent ping commands need a "-b" option to ping the broadcast address correctly.) You should be able to see both machines, of course, but if you don't even get a response from yourself, you've got a problem.
ASKER
Thanks guys the problem
is fixed.
my machine A was running NT
machine C was running redhat 6
Turns out the linux machine had
hung it's networking. Never
thinking there would be a problem
there I never checked, just thinking
the problem was on Machine B.
Rebooted the linux Machine and
everything works, just nicely.
Boy have I learnt alot though : )
is fixed.
my machine A was running NT
machine C was running redhat 6
Turns out the linux machine had
hung it's networking. Never
thinking there would be a problem
there I never checked, just thinking
the problem was on Machine B.
Rebooted the linux Machine and
everything works, just nicely.
Boy have I learnt alot though : )
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Also, remember that 192.168.x.x are local internet addresses. They can't be forwarded. There are literally 100,000's of 192.168.1.1 machines out there. Chaos would ensue . . .