Are you running Nutanix AHV hypervisor in your environment and want to replace Nutanix AHV host’s network card(s) / NICs or SATADOM cause of some reasons then you might encounter network communication issues.
After replacing Network card(s) the NICs or SATADOM Nutanix AHV host is not able to detect network card / NICs and lose the network connectivity.
Nutanix AHV hypersor having networking error to detect the Network cards / NICs and failed to reach to other AHV host and Nutanix CVM network.
In this case we need to troubleshoot the network issue
Network card Issue Causes
Nutanix AHV host’s network card is not detecting issue might occur due to following reasons
- Network card(s) / NICs replacement on Nutanix AHV host
- Duplicate MAC addresses
- SATADOM replacement
Nutanix AHV Network Troubleshooting
Nutanix native AHV hypervisor failed to detect Network card or NICs and not able to communicate with network.
First we need to determine the network issue on Nutanix AHV host
Step 1 : Log in to through SSH in Nutanix AHV host
Default credential
Userid : root
Password : nutanix/4u
Step 2 : check the name of the interfaces on your system, you may issue one of the following command
root@AHV# ipconfig -a
Result would be like this
root@AHV# ifconfig -a
br0 Link encap:Ethernet HWaddr 07:01:20:1A:01:7D
inet addr:192.168.5.1 Bcast:192.168.5.255
Mask:255.255.255.0
inet6 addr: fe80::a00:27ff:fe1d:17d/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:19835 errors:0 dropped:0 overruns:0 frame:0
TX packets:80091 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:20385937 (201.5 Mb) TX bytes:478750 (467.5 Kb)
eth0 Link encap:Ethernet HWaddr 07:01:20:1A:01:2A
inet addr:192.168.0.254 Bcast:192.168.0.255
Mask:255.255.255.0
inet6 addr: fe80::a00:27ff:fe1d:17a/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:14737 errors:0 dropped:0 overruns:0 frame:0
TX packets:7193 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:30385937 (301.5 Mb) TX bytes:508750 (527.5 Kb)
Step 3 : Check network interfaces status ( False | True ) and interface Speed ( 100 | 1000 | 10,000)
Log on to the Nutanix Controller VM ( CVM ), and then list the physical interfaces.
nutanix@cvm$ manage_ovs show_interfaces
Output similar to the following is displayed:
name mode link speed eth0 1000 false none eth1 1000 false none eth2 10000 false none eth3 10000 false none
Step 4 : Remove the MAC address entry from ifcfg-eth* file from each Nutanix AHV host
root@AHV# vi /etc/sysconfig/network-script/ifcfg-br0
# cat /etc/sysconfig/network-scripts/ifcfg-br0 DEVICE=eth0 TYPE=Ethernet NM_CONTROLLED=no ONBOOT=yes BOOTPROTO=none HWADDR=0c:c4:7a:64:ef:c0 <--Remove or comment this HWADDR address line
Step 5 : Delete network persistent rule file from Nutanix AHV host
# rm /etc/udev/rules.d/70-persistent-net.rules
After deleting the file take reboot of AHV host
Note : 70-persistent-net.rules file will be re-created after AHV host reboot
Step 6 : Verify network interfaces status must be Link detected: yes
Network interfaces name would be eth0, eth1, eth2, eth3, eth4, eth5, so on..
root#AHV# ethtool eth0
Result would be
root#AHV# ethtool eth0 Settings for eth0:10000baseT/Full Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full Advertised auto-negotiation: Yes Speed: 10000Mb/s Duplex: Full Port: Twisted Pair PHYAD: 1 Transceiver: internal Auto-negotiation: on Supports Wake-on: d Wake-on: d Current message level: 0x00000007 (7) Link detected: yes <---NIC is detcted by Nutanix AHV host
Step 7 : Now ping network gateway or other Nutanix AHV host or CVM to check network communication / reach-ability.
Step 8 : Optional If required take restart of network service
root@AHV# service network restart
Now Nutanix AHV host has detected the Network card(s) and communicating in network. Enjoy.!
You can gain more information on ethool network utility right below
It it additional information if you are interested in.
Additional Ethtool Commands
Through ethtool commands you can get more information related to network interfaces and commnunication
Display Netwrok Interface Statistics
root@AHV# ethtool –S eth0
Result would be
NIC statistics: tx_packets: 1800000 rx_packets: 1900000 tx_errors: 0 rx_errors: 0 rx_missed: 0 align_errors: 0 tx_single_collisions: 0 tx_multi_collisions: 0 unicast: 146180 broadcast: 47311 multicast: 82674 tx_aborted: 0 tx_underrun: 0
Display Version of Ethtool
root@AHV# ethtool --version
ethtool version 4.1
Display Interface Device Driver
root@AHV# ethtool -i eth0
Result would be
driver: e10000
version: 7.3.21-k8-NAPI
firmware-version:
bus-info: 0000:00:03.0
supports-statistics: yes
supports-test: yes
supports-eeprom-access: yes
supports-register-dump: yes
supports-priv-flags: no
Set Duplex Mode
root@AHV# ethtool -s eth0 speed 10000 duplex full
root@AHV# ethtool -s eth0 speed 10000 duplex half
Linux ethtool utility is very important and having awesome commands helps in network troubleshooting and get detailed information for each network interface.
Conclusion
Nutanix AHV hypervisor uses OVS switch to flow the networking for network communication, in case of Nutanix AHV hypervisor having networking issues in network card / NICs , SATADOM replacement.
Just need to troubleshoot the linux network files only and will take up to 10 minutes.
I hope Hyper Hci Blog helped you to troubleshoot Nutanix AHV networking issue. Follow Hyper Hci Blog on Social media to stay connected with us.