Server responds to 2 IP addresses

albracco · 03-16-2006, 10:50 AM

Red Hat 9 Enterprise. Old server at 192.168.25.11 being replaced. Put new server on network at 192.168.25.12. Copy data over and configure the new server. Unplug the old server, and change the new server's IP address to what the old server was (192.168.25.11). (That is so the 100 terminal emulation clients already set to connect to 192.168.25.11 will not have to be changed). Anyway, after changing the IP address to .11 using the ifconfig command, ifconfig still reported back .12 as the IP. I went and edited the ifcfg-eth0 network script and put .11 in there. Rebooted server, ran ifconfig, still reports the IP as .12. Next went to the GUI and ran network configuration, which showed eth0 as being set to .11 I checked every file where an IP address can be set (including /etc/hosts) and everything showed as .11. Just for fun, I tried pinging both IP's from another computer and they both replied! There is only one network card configured, it is set to .11, yet ifconfig thinks it's .12 and it responds to ping requests to both. Now, the server is working fine and the users are all connecting to it at .11, but why does ifconfig show .12? This is bothering me. Any ideas?

marozsas · 03-16-2006, 01:21 PM

Please, give us the "ifconfig -a" output.

albracco · 03-16-2006, 01:38 PM

OK, here it is:

eth0 Link encap:Ethernet HWaddr 00:14:22:1D:F1:30
inet addr:192.168.25.12 Bcast:192.168.25.255 Mask:255.255.255.0
inet6 addr: fe80::214:22ff:fe1d:f130/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:2249727 errors:0 dropped:0 overruns:0 frame:0
TX packets:2191224 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:146886799 (140.0 MiB) TX bytes:1188871022 (1.1 GiB)
Base address:0xecc0 Memory:fe6e0000-fe700000

eth1 Link encap:Ethernet HWaddr 00:14:22:1D:F1:31
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Base address:0xdcc0 Memory:fe4e0000-fe500000

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:85051 errors:0 dropped:0 overruns:0 frame:0
TX packets:85051 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:9931935 (9.4 MiB) TX bytes:9931935 (9.4 MiB)

sit0 Link encap:IPv6-in-IPv4
NOARP MTU:1480 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0

marozsas · 03-17-2006, 12:07 PM

Sorry the delay,

That is strange, indeed.

Is the old server up and running somewhere ?
if you do "ifconfig etho down" the clients lost connection ?

Quote:

Originally Posted by albracco

Anyway, after changing the IP address to .11 using the ifconfig command, ifconfig still reported back .12 as the IP

Can you check this again with the following commands, please ?

Code:

# ifconfig eth0
# ifconfig eth0 inet 192.168.25.11 netmask 255.255.255.0 up
# ifconfig eth0

You can simulate a reboot, at least to what is network related by:

Code:

# service network stop
# service network start

thanks,