Answers to Common Network Administration Questions
Refer to the following troubleshooting information when using the fixed
mode for network administration. For information about troubleshooting network
administration issues when using the reactive mode, see Answers to Common Profile-Based Network Configuration Questions.
For further details, see About Network Configuration Modes in Configuring and Managing Network Components in Oracle Solaris 11.3.
Question:
How do I determine which networking mode my system is using after an
installation?
Answer:
The networking mode is determined by the profile that is activated during
installation. If the DefaultFixed profile is activated, you are in
the fixed mode. If the Automatic profile is activated, you are in the
reactive mode. To determine which mode is currently active on your system, use the
netadm list command as follows:
# netadm list
Question:
My system defaulted to reactive mode after an installation. How can I fix this
problem?
Answer:
You need to switch to the fixed mode by enabling the DefaultFixed
profile. Use the netadm command as follows to switch the active
profile:
# netadm enable -p ncp DefaultFixed
Question:
I manually configured my system during an installation and the netadm
list command shows that I am using the fixed mode, but my system's network
is still not configured correctly. What should I do?
Answer:
The answer depends on which network component is not configured correctly. When in
the fixed mode, 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:
# 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
Then, set just the netmask property without deleting other existing IP configuration
as follows:
# ipadm set-addrprop -p prefixlen=len addrobj-name
See Chapter 3, Configuring and Administering IP Interfaces and Addresses in Oracle Solaris in Configuring and Managing Network Components in Oracle Solaris 11.3 for complete
instructions.
Question:
How do I configure a persistent default route on my system?
Answer:
Because the /etc/defaultrouter file is deprecated in Oracle
Solaris 11, 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 and configure routes (default or otherwise) as follows:
-
Display routes that are created persistently as follows:
# route -p show
-
Add a persistent default route as follows:
# route -p add default ip-address
-
Display the currently active routes on a system as follows:
# netstat -rn
See Creating Persistent (Static) Routes in Configuring and Managing Network Components in Oracle Solaris 11.3.
Question:
How do I display the MAC address of a system?
Answer:
Display the MAC addresses of the physical links in a system as follows:
# dladm show-phys -m
In Oracle Solaris 10, the ifconfig command is used to display
similar information. See the ifconfig(5) man page.
Display the MAC addresses of all of the links 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 MTU range my system supports?
Answer:
Use the ipadm show-ifprop command to determine this information,
as shown in the following example. The last column 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:
If you using the fixed mode, 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 Client in Configuring and Managing Network Components in Oracle Solaris 11.3 for instructions on how to configure naming services and how to
import naming services configuration on a client system 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 network
settings, as follows:
# sysconfig unconfigure -g network,naming_services
Question:
What is the difference between creating a virtual LAN (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 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 about which network administration strategies to use, see
Chapter 1, Summary of Oracle Solaris Network Administration in Strategies for Network Administration in Oracle Solaris 11.3.