I have a Linux kernel virtual bridge which contains interfaces eth1 and tap0:# brctl show br0bridge name     bridge id               STP enabled     interfacesbr0             8000.00016c404fa3       no              eth1                                                        tap0# Now when I view the MAC address table of the virtual switch, it shows port numbers 2(tap0 interface) and 3(eth1 interface):# brctl showmacs br0port no mac addr                is local?       ageing timer  3     00:00:5e:00:01:c9       no                 0.11  3     00:01:6c:40:2d:94       no                 0.53  3     00:01:6c:40:4f:a3       yes                0.00  3     00:01:6c:55:3a:72       no                55.33  3     00:02:b3:8d:48:a7       no                 0.53  3     00:0a:e4:2f:53:bb       no                 0.59  3     00:0b:82:0a:bc:cc       no                16.98  3     00:0c:29:07:3e:de       no                 9.12  3     00:0c:29:94:95:39       no               156.77  3     00:11:25:8c:7a:1a       no                16.50  3     00:11:5c:13:af:51       no                 0.42  3     00:15:60:5f:73:ee       no                84.73  3     00:16:3e:4b:8e:2f       no               175.61  3     00:19:e2:94:0b:f0       no                 7.48  3     00:19:e2:9e:df:f0       no                 0.00  3     00:1c:c0:61:20:a9       no                68.12  3     00:23:7d:83:c8:9f       no                26.35  3     00:25:9c:6e:74:e1       no               157.58  3     00:90:fb:47:d0:8c       no                 0.46  3     08:00:23:97:d0:87       no                14.62  3     24:be:05:1f:71:82       no                 0.56  3     24:be:05:1f:71:85       no                 0.51  3     24:be:05:25:95:8f       no                 0.55  3     4c:11:bf:98:ea:4f       no                 6.18  3     4c:11:bf:9c:60:52       no                32.01  3     78:24:af:37:10:70       no                51.89  3     78:24:af:37:11:06       no                50.89  3     88:51:fb:ec:45:1e       no                 7.12  2     f6:b8:99:06:0b:65       yes                0.00# What is connected to virtual bridge port number 1?
Understand Linux kernel virtual bridge port numbering
linux kernel;bridge