Solaris 10 - Troubleshoot NIC or Network link failure

There could be few network components which can cause a network failure.

1. NIC card or a Network Card
2. The Network Cable
3. The connected switch

Lets try to understand how we can troubleshoot these issues.

First check if the IP Address is already assigned to the network interface by running the ifconfig command.

1. In my case, we  have interface ce0 which already has a IP assigned and the status is showing as up.

# ifconfig -a
lo0: flags=2001000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4,VIRTUAL> mtu 8232 index 1
        inet 127.0.0.1 netmask ff000000
ce0: flags=1000803<UP,BROADCAST,MULTICAST,IPv4> mtu 1500 index 2
        inet 10.192.1.10netmask ffffff00 broadcast 10.192.XX.255
        ether 0:3:ba:9b:17:3a
ce1: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 3
        inet 192.168.XX.XX netmask fffffe00 broadcast 192.168.XX.255
        ether 0:3:ba:9b:17:39

Though the interface is showing as up ,now lets check the link status.

# dladm show-dev

ce0             link: down      speed: 0     Mbps       duplex: unknown

ce1             link: up        speed: 1000  Mbps       duplex: full

#

Now the link is showing as down, now lets try to find out the failure

Action Plan to Eliminate components

a. First change the cable to see if the cable has a problem -Eliminate cable

b. Check from the network team if there is a issue with the switch. -Eliminate switch

c. If both the above components are good then get the network card changed.