For example, the IP xxx.xxx.xxx.1-127 works, but xxx.xxx.xxx.128-251 are not working. They are working before. Thanks.

  • Define "work". Are nodes not able to access information out of the subnet, or the converse; nodes outside of the subnet can't access those nodes? Or something else? – sysadmin1138 May 24 '11 at 1:00
  • There's a website bind with each IP, I can see the website with IP xxx.xxx.xxx.1-127, but not with xxx.xxx.xxx.128-251. Those IPs are in the interface. Thanks. – garconcn May 24 '11 at 1:03
  • 1
    Can you ping the other addresses? Agreed with KCotreau; the most straightforward cause for this would be an incorrect subnet mask. One way this could happen is if the bad mask is part of the route directing traffic towards you in your upstream device (firewall, router, etc.). – BMDan May 24 '11 at 1:06
  • 1
    I can't ping them. I will get the network admin to fix it. They may changed something that I don't know. Thank you. – garconcn May 24 '11 at 1:08
  • 4
    For goodness sake, there's no such thing as a Class-C network. There hasn't been for years. And years. And years: meta.serverfault.com/questions/514/… and serverfault.com/questions/12854/cidr-for-dummies – Mark Henderson May 24 '11 at 1:47

The first thing that comes to mind is an incorrect subnet mask somewhere, but you really need to give more information. What exactly are you doing?

Not the answer you're looking for? Browse other questions tagged or ask your own question.