Symptoms
An error is seen about not being able to change the Management IP with new subnet/gateway in Unisphere or the ssh command line. Note: Both Unisphere and the command line will be unable to be logged into. Access from ipmitool on either SP must be used to continue and resolve the issue. Article 000022376 describes use of ipmitool. https://www.dell.com/support/kbdoc/en-us/000022376/dell-emc-unity-using-the-ipmitool-on-unity-systemsA check of the output of the command: svc_diag from the ssh shell shows no IP address configured for Management. Using the command below to check the configuration below will not show any valid info.Command: uemcli /net/if/mgmt showA valid configuration however shows the normal output. Notice the .128 Subnet mask.
uemcli /net/if/mgmt show
Storage system address: 127.0.0.1
Storage system port: 443
HTTPS connection
1: IP protocol version = ipv4
Address origin = static
IP address = 10.241.219.230
Subnet mask = 255.255.255.128
Gateway = 10.241.219.129
--------------------------------------------------------------------------------------------------------------------------------------------------------The following command was used to set the management address for a newly deployed system in this case, but it failed.
svc_initial_config -f friendlyname -4 "10.242.12.18 255.255.255.240 10.242.12.16"
friendlyname = name of the Unity system that is wanted
Cause
When changing the management IP address subnet with a new or changed gateway, it was found that an invalid gateway was chosen.The gateway used was actually the ID of the subnet (all 0 in hostbits). The subnet ID is invalid and cannot be used as a gateway per networking rules. Two special addresses in every subnet cannot be used as endpoints:
The first (lowest) address is the network identifier (subnet ID)The last (highest) address is the subnet broadcast address.
A subnet calculator also shows the Host range that is valid for any Host IP addresses needed. This includes the use of the gateway IP address.
Resolution
A valid gateway IP address must be chosen which allows successful configuration of the Management IP address. Once configured Unisphere can be used again for login.
