6 Replies Latest reply on Oct 3, 2012 3:02 PM by 946717

    one of two nic cards is not pingable

      I have two nic cards on node B (oracle linux 6.3). one card with default gateway is alright, but I can not ping the other card(200 segement) from A node(just pick any one node). on the same A node, i can ping all other nodes in the same 200 segment. the following is the "route" table and ifconfig eth1 on node B:

      # route
      Kernel IP routing table
      Destination Gateway Genmask Flags Metric Ref Use Iface
      default UG 0 0 0 eth2 * U 0 0 0 eth1 * U 0 0 0 eth2 * U 0 0 0 virbr0

      # ifconfig eth1
      eth1 Link encap:Ethernet HWaddr 00:17:A4:47:E1:78
      inet addr: Bcast: Mask:
      inet6 addr: fe80::217:a4ff:fe47:e178/64 Scope:Link
      RX packets:9867 errors:0 dropped:428566 overruns:0 frame:0
      TX packets:24 errors:0 dropped:0 overruns:0 carrier:0
      collisions:0 txqueuelen:1000
      RX bytes:5926159 (5.6 MiB) TX bytes:3087 (3.0 KiB)
      Interrupt:17 Memory:fa000000-fa012800

      Thank you!
        • 1. Re: one of two nic cards is not pingable
          Please be more specific in your description. I'm not sure if I can follow, but glancing your addresses and network mask I'd say you cannot ping between the networks because of your netmask being, which prevents broadcasting between the and networks. If you change your netmask to or it should work.
          • 2. Re: one of two nic cards is not pingable
            Sure. On node B, there are 2 nic cards, and IP's are, and, respectively. After the configurations all being done, nobody can ping For instance, on node A, I could not ping, however, I could ping all nodes in 200 segment from the node A.

            I can ping witout a problem. is the default gateway.

            Based on ifconfig eth1 on node A, this nic card seems UP, and configured correctly.

            Please check out the output of ifconfig eth1 and route in my previous message.

            Hopefully, i got this clearer a little bit more this time.
            Thank you!

            Edited by: 943714 on Sep 26, 2012 8:04 AM
            • 3. Re: one of two nic cards is not pingable
              As far as I can tell from your description, you cannot communicate between the 10.100.216 and 10.100.200 network without a netmask or having a separate gateway in each of the networks that bridges the two networks together. The gateway has be be within the same subnet as the source IP in order to be seen. With your current netmask, your network cannot see the gateway.
              • 4. Re: one of two nic cards is not pingable
                got your idea, however, I have a basic question on changing the netmask.

                I chnaged NETMASK= in /etc/sysconfig/network-scripts/ifcfg-eht1. and then "service network restart". How come the netmask could not be shown in "route" command, it is still showing I even reboot the server, same thing.

                Thank you!
                • 5. Re: one of two nic cards is not pingable
                  I suggest to check ifcfg-eth1 to see what value you have defined for PREFIX. Technically it should be 8 for a netmask and a network. If you want to use the value for NETMASK=, remove PREFIX or change it to 16 and restart the network using "service network restart".
                  • 6. Re: one of two nic cards is not pingable
                    it's getting complicated. It seems to me that Networking team needs to open up routes as well, I am going to give up on this approach. Thanks for your inputs.