[sub intf] test_sub_port_interfaces failed due to vlan tag stripped

[lolyu]

Description

test_sub_port_interfaces.py failed.

Steps to reproduce the issue:

1. config a sub-interface on the device: Ethernet12.10

root@str2-7050cx3-acs-01:/tmp# config vlan member del 1000 Ethernet12
root@str2-7050cx3-acs-01:/tmp# cat sub.json
{
    "VLAN_SUB_INTERFACE": {
        "Ethernet12.10": {
            "admin_status" : "up"
        },
        "Ethernet12.10|10.0.0.50/31": {}
    }
}
root@str2-7050cx3-acs-01:/tmp# sonic-cfggen -w -j sub.json
root@str2-7050cx3-acs-01:/tmp# show sub s
  Sub port interface    Speed    MTU    Vlan    Admin                  Type
--------------------  -------  -----  ------  -------  --------------------
       Ethernet12.10     100G   9100      10       up  802.1q-encapsulation
root@str2-7050cx3-acs-01:/tmp# show ip int
Interface        Master    IPv4 address/mask    Admin/Oper    BGP Neighbor    Neighbor IP
---------------  --------  -------------------  ------------  --------------  -------------
Ethernet12.10              10.0.0.50/31         up/up         N/A             N/A
Loopback0                  10.1.0.32/32         up/up         N/A             N/A
PortChannel0001            10.0.0.56/31         up/up         ARISTA01T1      10.0.0.57
PortChannel0002            10.0.0.58/31         up/up         ARISTA02T1      10.0.0.59
PortChannel0003            10.0.0.60/31         up/up         ARISTA03T1      10.0.0.61
PortChannel0004            10.0.0.62/31         up/up         ARISTA04T1      10.0.0.63
Vlan1000                   192.168.0.1/21       up/up         N/A             N/A
docker0                    240.127.1.1/24       up/down       N/A             N/A
eth0                       10.3.146.85/23       up/up         N/A             N/A
lo                         127.0.0.1/16         up/up         N/A             N/A

2. config a corresponding sub-interface on the PTF port: eth3.10

root@5146357445fe:~# ip link add link eth3 name eth3.10 type vlan id 10  
root@5146357445fe:~# ip address add 10.0.0.51/31 dev eth3.10  
root@5146357445fe:~# ip link set eth3.10 up  
root@5146357445fe:~# ifconfig eth3.10  
eth3.10: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9216
        inet 10.0.0.51  netmask 255.255.255.254  broadcast 0.0.0.0
        inet6 fe80::9a03:9bff:fe03:2289  prefixlen 64  scopeid 0x20<link>
        ether 98:03:9b:03:22:89  txqueuelen 1000  (Ethernet)
        RX packets 159  bytes 12026 (11.7 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 171  bytes 13634 (13.3 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

3. ping 10.0.0.51 from DUT and dump packets from DUT interface Ethernet12

• ping from DUT, failed due to no ARP reply.

root@str2-7050cx3-acs-01:~# ping 10.0.0.51
PING 10.0.0.51 (10.0.0.51) 56(84) bytes of data.
From 10.0.0.50 icmp_seq=1 Destination Host Unreachable
From 10.0.0.50 icmp_seq=2 Destination Host Unreachable
From 10.0.0.50 icmp_seq=3 Destination Host Unreachable
^C
--- 10.0.0.51 ping statistics ---
6 packets transmitted, 0 received, +3 errors, 100% packet loss, time 130ms
pipe 4
root@str2-7050cx3-acs-01:~#

• dump from DUT interface Ethernet12, the ARP reply is not tagged.

root@str2-7050cx3-acs-01:~# tcpdump -i Ethernet12 -nev
tcpdump: listening on Ethernet12, link-type EN10MB (Ethernet), capture size 262144 bytes
10:37:18.321798 94:8e:d3:05:34:e4 > ff:ff:ff:ff:ff:ff, ethertype 802.1Q (0x8100), length 46: vlan 10, p 0, ethertype ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 10.0.0.51 tell 10.0.0.50, length 28
10:37:18.321993 98:03:9b:03:22:89 > 94:8e:d3:05:34:e4, ethertype ARP (0x0806), length 56: Ethernet (len 6), IPv4 (len 4), Reply 10.0.0.51 is-at 98:03:9b:03:22:89, length 42
10:37:19.345754 94:8e:d3:05:34:e4 > ff:ff:ff:ff:ff:ff, ethertype 802.1Q (0x8100), length 46: vlan 10, p 0, ethertype ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 10.0.0.51 tell 10.0.0.50, length 28
10:37:19.345878 98:03:9b:03:22:89 > 94:8e:d3:05:34:e4, ethertype ARP (0x0806), length 56: Ethernet (len 6), IPv4 (len 4), Reply 10.0.0.51 is-at 98:03:9b:03:22:89, length 42

• dump from the sub-interface Ethernet12.10, no ARP reply is present.

root@str2-7050cx3-acs-01:~# tcpdump -i Ethernet12.10 -nev
tcpdump: listening on Ethernet12.10, link-type EN10MB (Ethernet), capture size 262144 bytes
10:51:02.257742 94:8e:d3:05:34:e4 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Request who-has 10.0.0.51 tell 10.0.0.50, length 28
10:51:03.281743 94:8e:d3:05:34:e4 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Request who-has 10.0.0.51 tell 10.0.0.50, length 28
10:51:04.305786 94:8e:d3:05:34:e4 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Request who-has 10.0.0.51 tell 10.0.0.50, length 28
10:51:05.329740 94:8e:d3:05:34:e4 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Request who-has 10.0.0.51 tell 10.0.0.50, length 28
^C
4 packets captured
4 packets received by filter
0 packets dropped by kernel
root@str2-7050cx3-acs-01:~#

• dump from PTF port eth3, both ARP request and reply are tagged.

root@2aff8f65b554:~# tcpdump -i eth3 -nev
tcpdump: listening on eth3, link-type EN10MB (Ethernet), capture size 262144 bytes
10:25:31.353874 94:8e:d3:05:34:e4 > ff:ff:ff:ff:ff:ff, ethertype 802.1Q (0x8100), length 64: vlan 10, p 0, ethertype ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 10.0.0.51 tell 10.0.0.50, length 46
10:25:31.353896 98:03:9b:03:22:89 > 94:8e:d3:05:34:e4, ethertype 802.1Q (0x8100), length 46: vlan 10, p 0, ethertype ARP, Ethernet (len 6), IPv4 (len 4), Reply 10.0.0.51 is-at 98:03:9b:03:22:89, length 28
10:25:32.378519 94:8e:d3:05:34:e4 > ff:ff:ff:ff:ff:ff, ethertype 802.1Q (0x8100), length 64: vlan 10, p 0, ethertype ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 10.0.0.51 tell 10.0.0.50, length 46
10:25:32.378541 98:03:9b:03:22:89 > 94:8e:d3:05:34:e4, ethertype 802.1Q (0x8100), length 46: vlan 10, p 0, ethertype ARP, Ethernet (len 6), IPv4 (len 4), Reply 10.0.0.51 is-at 98:03:9b:03:22:89, length 28

4. add the interface Ethernet12 back to Vlan1000, then do the sub-steps as step 3

• add the interface to Vlan1000 then ping from DUT, ping is OK.

root@str2-7050cx3-acs-01:~# config vlan member add 1000 Ethernet12
root@str2-7050cx3-acs-01:~# ping 10.0.0.51
PING 10.0.0.51 (10.0.0.51) 56(84) bytes of data.
64 bytes from 10.0.0.51: icmp_seq=1 ttl=64 time=0.288 ms
64 bytes from 10.0.0.51: icmp_seq=2 ttl=64 time=0.245 ms
64 bytes from 10.0.0.51: icmp_seq=3 ttl=64 time=0.241 ms
^C
--- 10.0.0.51 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 32ms
rtt min/avg/max/mdev = 0.241/0.258/0.288/0.021 ms
root@str2-7050cx3-acs-01:~# docker exec -it swss bash
root@str2-7050cx3-acs-01:/# arping 10.0.0.51
ARPING 10.0.0.51
56 bytes from 98:03:9b:03:22:89 (10.0.0.51): index=0 time=400.453 usec
56 bytes from 98:03:9b:03:22:89 (10.0.0.51): index=1 time=133.342 usec
56 bytes from 98:03:9b:03:22:89 (10.0.0.51): index=2 time=123.022 usec
56 bytes from 98:03:9b:03:22:89 (10.0.0.51): index=3 time=125.741 usec
56 bytes from 98:03:9b:03:22:89 (10.0.0.51): index=4 time=102.873 usec
56 bytes from 98:03:9b:03:22:89 (10.0.0.51): index=5 time=116.024 usec
56 bytes from 98:03:9b:03:22:89 (10.0.0.51): index=6 time=180.733 usec
56 bytes from 98:03:9b:03:22:89 (10.0.0.51): index=7 time=124.256 usec
^C
--- 10.0.0.51 statistics ---
8 packets transmitted, 8 packets received,   0% unanswered (0 extra)
rtt min/avg/max/std-dev = 0.103/0.163/0.400/0.092 ms

• dump from DUT interface Ethernet12, both ARP request and reply are tagged.

root@str2-7050cx3-acs-01:~# tcpdump -i Ethernet12 -nev
tcpdump: listening on Ethernet12, link-type EN10MB (Ethernet), capture size 262144 bytes
10:42:39.723935 94:8e:d3:05:34:e4 > ff:ff:ff:ff:ff:ff, ethertype 802.1Q (0x8100), length 62: vlan 10, p 0, ethertype ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 10.0.0.51 tell 10.0.0.50, length 44
10:42:39.724048 98:03:9b:03:22:89 > 94:8e:d3:05:34:e4, ethertype 802.1Q (0x8100), length 60: vlan 10, p 0, ethertype ARP, Ethernet (len 6), IPv4 (len 4), Reply 10.0.0.51 is-at 98:03:9b:03:22:89, length 42
10:42:40.725026 94:8e:d3:05:34:e4 > ff:ff:ff:ff:ff:ff, ethertype 802.1Q (0x8100), length 62: vlan 10, p 0, ethertype ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 10.0.0.51 tell 10.0.0.50, length 44
10:42:40.725208 98:03:9b:03:22:89 > 94:8e:d3:05:34:e4, ethertype 802.1Q (0x8100), length 60: vlan 10, p 0, ethertype ARP, Ethernet (len 6), IPv4 (len 4), Reply 10.0.0.51 is-at 98:03:9b:03:22:89, length 42
^C
4 packets captured
4 packets received by filter
0 packets dropped by kernel
root@str2-7050cx3-acs-01:~#

• dump from the sub-interface Ethernet12.10, both ARP request and reply are present.

root@str2-7050cx3-acs-01:~# tcpdump -i Ethernet12.10 -nev
tcpdump: listening on Ethernet12.10, link-type EN10MB (Ethernet), capture size 262144 bytes
10:53:37.133149 94:8e:d3:05:34:e4 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 58: Ethernet (len 6), IPv4 (len 4), Request who-has 10.0.0.51 tell 10.0.0.50, length 44
10:53:37.133293 98:03:9b:03:22:89 > 94:8e:d3:05:34:e4, ethertype ARP (0x0806), length 56: Ethernet (len 6), IPv4 (len 4), Reply 10.0.0.51 is-at 98:03:9b:03:22:89, length 42
10:53:38.133771 94:8e:d3:05:34:e4 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 58: Ethernet (len 6), IPv4 (len 4), Request who-has 10.0.0.51 tell 10.0.0.50, length 44
10:53:38.133917 98:03:9b:03:22:89 > 94:8e:d3:05:34:e4, ethertype ARP (0x0806), length 56: Ethernet (len 6), IPv4 (len 4), Reply 10.0.0.51 is-at 98:03:9b:03:22:89, length 42
^C
4 packets captured
4 packets received by filter
0 packets dropped by kernel

Describe the results you received:

Describe the results you expected:

• the packets dumped a routed interface with destinatination to the sub-interface should have VLAN tag.

root@str2-7050cx3-acs-01:~# show version

SONiC Software Version: SONiC.master.20696-90801dc1b
Distribution: Debian 10.10
Kernel: 4.19.0-12-2-amd64
Build commit: 90801dc1b
Build date: Mon Jun 21 13:06:52 UTC 2021
Built by: AzDevOps@sonic-build-workers-000EL0

Platform: x86_64-arista_7050cx3_32s
HwSKU: Arista-7050CX3-32S-C32
ASIC: broadcom
ASIC Count: 1
Serial Number: JPE20432334
Model Number: DCS-7050CX3-32S-SSD
Hardware Revision: N/A
Uptime: 10:44:02 up 31 min,  2 users,  load average: 1.26, 1.36, 1.33

Docker images:
REPOSITORY                    TAG                      IMAGE ID            SIZE
docker-platform-monitor       latest                   3761db0b74f2        627MB
docker-platform-monitor       master.20696-90801dc1b   3761db0b74f2        627MB
docker-snmp                   latest                   94b495dd874c        454MB
docker-snmp                   master.20696-90801dc1b   94b495dd874c        454MB
docker-sflow                  latest                   97cf7f4d30a8        425MB
docker-sflow                  master.20696-90801dc1b   97cf7f4d30a8        425MB
docker-teamd                  latest                   223505a51cc1        424MB
docker-teamd                  master.20696-90801dc1b   223505a51cc1        424MB
docker-macsec                 latest                   e39d62c46e8a        427MB
docker-macsec                 master.20696-90801dc1b   e39d62c46e8a        427MB
docker-lldp                   latest                   3c68e4ed3dfe        453MB
docker-lldp                   master.20696-90801dc1b   3c68e4ed3dfe        453MB
docker-orchagent              latest                   aa2976791cbf        442MB
docker-orchagent              master.20696-90801dc1b   aa2976791cbf        442MB
docker-router-advertiser      latest                   4f4d8c759175        413MB
docker-router-advertiser      master.20696-90801dc1b   4f4d8c759175        413MB
docker-nat                    latest                   a000f07473b0        427MB
docker-nat                    master.20696-90801dc1b   a000f07473b0        427MB
docker-sonic-mgmt-framework   latest                   107cc849fcd6        570MB
docker-sonic-mgmt-framework   master.20696-90801dc1b   107cc849fcd6        570MB
docker-dhcp-relay             latest                   fcb54a012b2d        420MB
docker-dhcp-relay             master.20696-90801dc1b   fcb54a012b2d        420MB
docker-sonic-telemetry        latest                   5691108f535b        501MB
docker-sonic-telemetry        master.20696-90801dc1b   5691108f535b        501MB
docker-fpm-frr                latest                   dddc5326440b        442MB
docker-fpm-frr                master.20696-90801dc1b   dddc5326440b        442MB
docker-syncd-brcm             latest                   10b635141195        705MB
docker-syncd-brcm             master.20696-90801dc1b   10b635141195        705MB
docker-database               latest                   1188cff4d481        413MB
docker-database               master.20696-90801dc1b   1188cff4d481        413MB

[OleksandrKozodoi]

A similar issue was reproduced in the past and was fixed by 1573. Probably that issue relates to new fails of test_sub_port_interfaces.

[lolyu]

Could not repro with the latest public image.