Answers to Common Network Administration Questions
Refer to the following information when troubleshooting general network administration
issues.
Question:
I configured my system during an installation but my system's network is still not
configured correctly after the installation. What should I do?
Answer:
The answer depends on which network component is not configured correctly. You use
the dladm and ipadm commands to configure the
network. Given the type of configuration parameters that can be set at installation
time, most likely an IP interface or address is not configured correctly.
To determine which network components need to be reconfigured, start by displaying
the current network configuration as follows:
# ipadm
If the IP address is incorrect, you will need to delete that address and then create
the correct IP address, for example, a static IP address or a DHCP address.
The following example shows how to delete the IPv6 addrconf
portion of an IP configuration. In this example the IPv6 addrconf
address is determined by running the ipadm command as follows:
# ipadm
NAME CLASS/TYPE STATE UNDER ADDR
lo0 loopback ok -- --
lo0/v4 static ok -- 127.0.0.1/8
lo0/v6 static ok -- ::1/128
net0 ip ok -- --
net0/v4 dhcp ok -- 203.0.113.10/24
net0/v6 addrconf ok -- fe80::8:20ff:fe90:10df/10
# ipadm delete-addr net2/v6
# ipadm
NAME CLASS/TYPE STATE UNDER ADDR
lo0 loopback ok -- --
lo0/v4 static ok -- 127.0.0.1/8
lo0/v6 static ok -- ::1/128
net0 ip ok -- --
net0/v4 dhcp ok -- 203.0.113.10/24
See Chapter 3, Configuring and Administering IP Interfaces and Addresses in Oracle Solaris in Configuring and Managing Network Components in Oracle Solaris 11.4 for complete
instructions.
Question:
How do I configure a persistent default route on my system?
Answer:
Because the /etc/defaultrouter file has been removed in this
Oracle Solaris release, you can no longer manage default routes by editing this file.
Also, after a fresh installation, you can no longer check this file to determine the
system's default route.
-
Display routes that are created persistently as follows:
# route -p show
-
Add a persistent default route as follows:
# route -p add default gateway
-
Display the currently active routes on a system as follows:
# netstat -rn
See Creating Persistent (Static) Routes in Configuring an Oracle Solaris 11.4 System as a Router or a Load Balancer for instructions.
Question:
How do I display the MAC address of a system?
Answer:
Display the MAC addresses of the physical links that are in a system as
follows:
# dladm show-phys -m
The output of this command is similar to the output of the
ifconfig command that was used in previous releases. See the ifconfig(7) man page.
Display the MAC addresses of all of the links that are in a system (physical and
non-physical) as follows:
# dladm show-linkprop -p mac-address
Question:
I can no longer use the dladm show-dev command to display the
physical links that are in my system? What command do I use now?
Answer:
Use the dladm show-phys command as follows:
# dladm show-phys
LINK MEDIA STATE SPEED DUPLEX DEVICE
net0 Ethernet up 0 unknown vnet0
Question:
How do I display the mapping between link names, devices, and locations on a
system?
Answer:
Use the dladm show-phys command with the –L
option as follows:
# dladm show-phys -L
LINK DEVICE LOCATION
net0 e1000g0 MB
net1 e1000g1 MB
net2 e1000g2 MB
net3 e1000g3 MB
net4 ibp0 MB/RISER0/PCIE0/PORT1
net5 ibp1 MB/RISER0/PCIE0/PORT2
net6 eoib2 MB/RISER0/PCIE0/PORT1/cloud-nm2gw-2/1A-ETH-2
net7 eoib4 MB/RISER0/PCIE0/PORT2/cloud-nm2gw-2/1A-ETH-2
Question:
What command do I use to determine the maximum transmission unit (MTU) range that my
system supports?
Answer:
Use the ipadm show-ifprop command to determine this information.
The last column of the output displays the supported MTU ranges.
# ipadm show-ifprop -p mtu interface
Question:
What if the naming services settings on my system are lost or not configured
correctly after an installation?
Answer:
The naming services configuration should be what you specified during the
installation. In this release, naming services are configured through the Service
Management Facility (SMF). See Chapter 4, Administering Naming and Directory Services on an Oracle Solaris System in Configuring and Managing Network Components in Oracle Solaris 11.4 for
instructions on how to configure naming services and how to import naming services
configuration on a client system, if necessary, after an installation.
Question:
How can I start over and reconfigure all of the network settings for my
system?
Answer:
You can unconfigure and reconfigure an Oracle Solaris instance, including its
network and naming service settings, as follows:
# sysconfig unconfigure -g network,naming_services
Question:
What is the difference between creating a virtual local area network (VLAN) with the
dladm create-vlan command and a virtual NIC (VNIC) with the
dladm create-vnic -v VID ... command? Also, what are the unique
features of both commands that would dictate the use of one rather than the
other?
Answer:
Depending on your networking needs and what you are trying to accomplish, you would
use each of these features for different purposes.
A VLAN is a subdivision of a LAN at the datalink layer (L2) of the network stack.
VLANs enable you to divide your network into subnetworks without having to add to the
physical network environment. So, the subnetworks are virtual and they share the same
physical network resources. VLANs facilitate network administration by using smaller
groups that are easier to maintain.
VNICs are virtual network devices that use the same datalink interface as a physical
network interface card (NIC). You configure VNICs over an underlying datalink. When
VNICs are configured, they behave like physical NICs. Depending on the network interface
that is in use, you can explicitly assign a MAC address to a VNIC other than the default
address.
For more information using network administration features to obtain a desired
result, see Chapter 1, Summary of Oracle Solaris Network Administration in Strategies for Network Administration in Oracle Solaris 11.4.