Recovering from DNS misconfiguration

When specifying DNS settings for the first time, specifying incorrect DNS settings can cause issues with DNS resolution

If this happens, do not attempt to rerun the script v3/tacp_switch_config_v3.

Important:

This procedure can be performed only by Lenovo Professional Services.

To recover from DNS misconfiguration, follow these steps:

  1. Update /etc/tacp/tacp_switch_resource.sh with the correct DNS IP address on both interconnect switches:
    ### Hardware management network DHCP configuration ###
    
    BMC_DHCP_START=10.103.31.2
    BMC_DHCP_END=10.103.31.253
    BMC_ROUTER_IP=$BMC_VLAN_IP
    BMC_PREFIX=$BMC_VLAN_IP_PREFIX
    DNS=10.0.64.10
    
    #SWITCH_HA="DS-V3"|"SS-V3"
    
    SWITCH_HA="DS-V3"
  2. Edit /etc/dhcp/vlan-mgmt.conf on the primary interconnect switch:

    This file is used to specify the hardware management network setting.

    subnet 10.103.31.0 netmask  255.255.255.0 {
           option domain-name-servers 10.0.64.10;
           option routers 10.103.31.1;
           default-lease-time 43200;
           max-lease-time 43200;
    
           pool {
             range 10.103.31.2 10.103.31.253;
           }
    }
  3. Edit /etc/dhcp/vlan-main.conf on the primary interconnect switch:
    subnet 10.102.31.0 netmask 255.255.255.0 {
           option domain-name-servers 10.0.64.10;
           option routers 10.102.31.254;
           default-lease-time 43200;
           max-lease-time 43200;
    
    #Disable DHCP-HA until off rules are fixed
    #failover peer "failover-partner";
    
           pool {
              range 10.102.31.2 10.102.31.253;
           }
    }
  4. Restart the DHCP server on the primary interconnect switch:

    > sudo service isc-dhcp-server stop > sudo service isc-dhcp-server start