why different pci slot use same device serial number?

Question

my questions are:

1, why pci~02_00_0 and pci~02_00_1 use the same Device Serial Number(a0-36-9f-ff-ff-b6-dd-c2)?

2, which pci slot is eth1(a0:36:9f:b6:dd:c3) corresponding to?

details are below.

*[root@localhost ~]# lspci |grep Ethernet

02:00.0 Ethernet controller: Intel Corporation I350 Gigabit Network Connection (rev 01)

02:00.1 Ethernet controller: Intel Corporation I350 Gigabit Network Connection (rev 01)

06:00.0 Ethernet controller: Intel Corporation I210 Gigabit Network Connection (rev 03)

07:00.0 Ethernet controller: Intel Corporation I210 Gigabit Network Connection (rev 03)

[root@localhost ~]# lspci -vv -s 02:00.0 |grep Serial

Capabilities: [140 v1] Device Serial Number a0-36-9f-ff-ff-b6-dd-c2

[root@localhost ~]# lspci -vv -s 02:00.1 |grep Serial

Capabilities: [140 v1] Device Serial Number a0-36-9f-ff-ff-b6-dd-c2

[root@localhost ~]# lspci -vv -s 06:00.0 |grep Serial

Capabilities: [140 v1] Device Serial Number 0c-c4-7a-ff-ff-97-80-a2

[root@localhost ~]# lspci -vv -s 07:00.0 |grep Serial

Capabilities: [140 v1] Device Serial Number 0c-c4-7a-ff-ff-97-80-a3

[root@localhost ~]# ip link ls

1: lo: mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00

2: eth0: mtu 1500 qdisc mq master ovs-system state UP mode DEFAULT qlen 1000 link/ether a0:36:9f:b6:dd:c2 brd ff:ff:ff:ff:ff:ff

3: eth1: mtu 1500 qdisc mq state UP mode DEFAULT qlen 1000 link/ether a0:36:9f:b6:dd:c3 brd ff:ff:ff:ff:ff:ff

4: eth2: mtu 1500 qdisc mq state UP mode DEFAULT qlen 1000 link/ether 0c:c4:7a:97:80:a2 brd ff:ff:ff:ff:ff:ff

5: eth3: mtu 1500 qdisc mq state DOWN mode DEFAULT qlen 1000 link/ether 0c:c4:7a:97:80:a3 brd ff:ff:ff:ff:ff:ff*

Answer 1

That's a dual port card. In other words, there are two network interfaces connected to the same PCI card. Both report the same serial number because they are part of the same physical part.

(In PCI terms, 02:00.0 and 02:00.1 are two different "functions" on the same "bus" and "slot".)

As to which is eth1, you would have to look at the datasheet for the Intel I350. It should tell which of them gets the first MAC address (...:c2) and which gets the second (...:c3). My guess would be that eth1 (...:c3) is 02:00.1 but that's just a guess.

It's often easiest to just plug a live cable into one of the ports and see which of eth0 and eth1 reports link-established (you should be able to use ethtool for that).