Second network card configuration not working
Solution 1
It should be noted that your NICs aren't properly 'working'. Your ifconfig output doesn't show the 'RUNNING' required for there to be a properly working link. note the line UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
from your eth0 interface. There's no 'RUNNING' evident in the eth1 output. In my experience, this indicates a low level issue. eg: Bad/disconnected cabling.
Is is possible the NIC you have plugged your cable into is NOT eth1? Servers can get some weird naming going on. Try checking the output of /var/log/messages, to see if it reports an interface getting (dis)connected. Likewise, see if you get any diagnostic info there when you connect/disconnect, or during boot. Check and see if this is occurring on all 5 boxes. You may also want to try the graphical configuration tool, just in case you've got a typo in the configuration file. (system-config-network
)
Solution 2
Think a bit about your subnet setup:
IPADDR=10.72.11.236
BROADCAST=10.72.11.191
NETMASK=255.255.255.192
NETWORK=10.72.11.128
In base 2:
236 is 1110 1100
191 is 1011 1111
192 is 1100 0000
128 is 1000 0000
Your IPs are outside your subnet - 10.72.11.236 is not in 10.72.11.128/26, 10.72.11.172 is. Neither is 17.72.11.235 but 10.72.11.171 is. Either change your IPs or change your broadcast to .255 and your network to .192. Alternatively (unless it's being dictated to you), run in the lower half of 10.72.11.0 (i.e. 10.72.11.0/26) or just use a /24 and save yourself the hassle.
Solution 3
Try using ipcalc from http://jodies.de/ipcalc, it is a big help when configuring networks and subnetworks.
# ipcalc 10.72.11.236/255.255.255.192
Address: 10.72.11.236 00001010.01001000.00001011.11 101100
Netmask: 255.255.255.192 = 26 11111111.11111111.11111111.11 000000
Wildcard: 0.0.0.63 00000000.00000000.00000000.00 111111
=>
Network: 10.72.11.192/26 00001010.01001000.00001011.11 000000
HostMin: 10.72.11.193 00001010.01001000.00001011.11 000001
HostMax: 10.72.11.254 00001010.01001000.00001011.11 111110
Broadcast: 10.72.11.255 00001010.01001000.00001011.11 111111
Hosts/Net: 62 Class A, Private Internet
Richard
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Sebas
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Updated on September 17, 2022Comments
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Sebas almost 2 years
I have 4 servers running Centos 5. All of them have two ethernet network cards.
I have configured
192.168.1.x
IP addresses on theireth0
card. They are all connected to the same switch using theireth0
card and they are all working.I have configured
10.72.11.x
IP addresses on theireth1
card.They are all connected to the same switch - a different one from the switch used witheth0
card - using theireth1
card and they are NOT all working.Their configuration files is like:
DEVICE=eth1 BOOTPROTO=static IPADDR=10.72.11.236 BROADCAST=10.72.11.191 NETMASK=255.255.255.192 NETWORK=10.72.11.128 HWADDR=84:2B:2B:55:4B:98 IPV6INIT=yes IPV6_AUTOCONF=yes ONBOOT=yes
The interface is starting and configured as I need.
[root@sql1 network-scripts]# ifconfig **eth0** Link encap:Ethernet HWaddr 84:2B:2B:55:4B:97 inet addr:192.168.1.105 Bcast:192.168.1.255 Mask:255.255.255.0 inet6 addr: fe80::862b:2bff:fe55:4b97/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:2981 errors:0 dropped:0 overruns:0 frame:0 TX packets:319 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:386809 (377.7 KiB) TX bytes:66134 (64.5 KiB) Interrupt:36 Memory:da000000-da012800 **eth1** Link encap:Ethernet HWaddr 84:2B:2B:55:4B:98 inet addr:10.72.11.236 Bcast:10.72.11.191 Mask:255.255.255.192 UP 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) Interrupt:48 Memory:dc000000-dc012800
I also added a
route-eth1
file that looks like:10.0.0.0/8 via 10.72.11.254
Routing looks fine to me:
[root@sql1 network-scripts]# netstat -rn Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 10.72.11.192 0.0.0.0 255.255.255.192 U 0 0 0 eth1 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth1 10.0.0.0 10.72.11.254 255.0.0.0 UG 0 0 0 eth1 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0
But I cannot ping one server from the other.
[root@sql1 network-scripts]# ping 10.72.11.235 PING 10.72.11.235 (10.72.11.235) 56(84) bytes of data. From 10.72.11.236 icmp_seq=1 Destination Host Unreachable From 10.72.11.236 icmp_seq=2 Destination Host Unreachable From 10.72.11.236 icmp_seq=3 Destination Host Unreachable From 10.72.11.236 icmp_seq=4 Destination Host Unreachable From 10.72.11.236 icmp_seq=5 Destination Host Unreachable From 10.72.11.236 icmp_seq=6 Destination Host Unreachable ^C --- 10.72.11.235 ping statistics --- 7 packets transmitted, 0 received, +6 errors, 100% packet loss, time 6033ms, pipe 3
What am I doing wrong?
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Jason B Shrout over 13 yearsIt appears you got 2 separate segments going on your proposed single segment switching network. Unless you are running vlans on that switch, it may be confused depending on your configuration and in this specific configuration its going to be. Trying bumping your 10.72.11.X networks all to 24 bits.