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aihx
Contributor
Contributor

MAC address in card VS mac address in OS

Dear Support,

The first I have vcenter,

I have virtual machine with 2 network card with 2 MAC example: 00:50:56:b7:42:3b and 00:50:56:b7:42:3c

this card connect to port-group (distributed virtual port group)

in OS when I run ifconfig, it show 2 mac 00:50:56:b7:42:2b and 00:50:56:b7:42:2c

this server run ok about network (can ping, connect to another server)

pls let me know what happen with this virtual machine, how the network can work?

Regards

AiHX

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abhilashhb
VMware Employee
VMware Employee

Can you paste the screenshots of the network card details and ifconfig output?

Abhilash B
LinkedIn : https://www.linkedin.com/in/abhilashhb/

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aihx
Contributor
Contributor

network.png

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MKguy
Virtuoso
Virtuoso

The MAC as seen by the Guest should be identical to what's configured for the VM, but it's possible that the Guest is overwriting the "physical" MAC. Looks like you run some sort of clustering on there, this might alter the MAC displayed in the OS or source MAC used in ethernet frames.

Check the following commands too:

# grep -i hwaddr /etc/sysconfig/network-scripts/ifcfg-eth*

HWADDR=00:50:56:74:33:b6

(Depending on your Linux distro, you might have interface configuration files elsewhere or in another format)

# lspci | grep -i ether | awk {'print $1'} | while read pci ; do cat /sys/bus/pci/devices/*$pci/net/eth*/address ; done

00:50:56:74:33:b6

# ip link show eth0

2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UNKNOWN qlen 1000

    link/ether 00:50:56:74:33:b6 brd ff:ff:ff:ff:ff:ff

# tcpdump -i eth0 -nne -c 10

(check the source MAC of outgoing frames)

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