Hi,

I had the same issue, what happend is that the network went down and the server flooded the switch with traffic.

Mar  1 19:51:08 microserver kernel: [76180.035137] ------------[ cut here ]------------
Mar  1 19:51:08 microserver kernel: [76180.035142] NETDEV WATCHDOG: eno1 (tg3): transmit queue 0 timed out
Mar  1 19:51:08 microserver kernel: [76180.035172] WARNING: CPU: 1 PID: 0 at net/sched/sch_generic.c:447 dev_watchdog+0x258/0x260
Mar  1 19:51:08 microserver kernel: [76180.035174] Modules linked in: vhost_net vhost tap xt_CHECKSUM xt_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp ip6table_mangle ip6table_nat iptable_mangle nf_tables nfnetlink ip6table_filter ip6_tables aufs iptable_nat xt_MASQUERADE nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter bpfilter wireguard ip6_udp_tunnel udp_tunnel overlay bridge stp llc binfmt_misc intel_rapl_msr intel_rapl_common x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm mgag200 crct10dif_pclmul drm_vram_helper ipmi_ssif ghash_clmulni_intel ttm aesni_intel crypto_simd drm_kms_helper cryptd glue_helper i2c_algo_bit fb_sys_fops syscopyarea sysfillrect sysimgblt rapl intel_cstate serio_raw hpilo joydev ipmi_si input_leds ipmi_devintf ie31200_edac ipmi_msghandler mac_hid acpi_power_meter sch_fq_codel parport_pc drm ppdev lp parport sunrpc ip_tables x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0
Mar  1 19:51:08 microserver kernel: [76180.035222]  multipath linear hid_generic usbhid hid gpio_ich crc32_pclmul lpc_ich psmouse ahci libahci tg3
Mar  1 19:51:08 microserver kernel: [76180.035231] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.4.0-66-generic #74-Ubuntu
Mar  1 19:51:08 microserver kernel: [76180.035232] Hardware name: HP ProLiant MicroServer Gen8, BIOS J06 04/04/2019
Mar  1 19:51:08 microserver kernel: [76180.035235] RIP: 0010:dev_watchdog+0x258/0x260
Mar  1 19:51:08 microserver kernel: [76180.035238] Code: 85 c0 75 e5 eb 9f 4c 89 ff c6 05 ae 8f e7 00 01 e8 0d b2 fa ff 44 89 e9 4c 89 fe 48 c7 c7 58 a3 83 a1 48 89 c2 e8 c3 c3 70 ff <0f> 0b eb 80 0f 1f 40 00 66 66 66 66 90 55 48 89 e5 41 57 49 89 d7
Mar  1 19:51:08 microserver kernel: [76180.035240] RSP: 0018:ffffb90fc02b0e30 EFLAGS: 00010286
Mar  1 19:51:08 microserver kernel: [76180.035242] RAX: 0000000000000000 RBX: ffff8eaa762bf500 RCX: 0000000000000006
Mar  1 19:51:08 microserver kernel: [76180.035243] RDX: 0000000000000007 RSI: 0000000000000096 RDI: ffff8eaa7aa578c0
Mar  1 19:51:08 microserver kernel: [76180.035244] RBP: ffffb90fc02b0e60 R08: 00000000000003ea R09: 0000000000000004
Mar  1 19:51:08 microserver kernel: [76180.035245] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000005
Mar  1 19:51:08 microserver kernel: [76180.035246] R13: 0000000000000000 R14: ffff8eaa762ea480 R15: ffff8eaa762ea000
Mar  1 19:51:08 microserver kernel: [76180.035248] FS:  0000000000000000(0000) GS:ffff8eaa7aa40000(0000) knlGS:0000000000000000
Mar  1 19:51:08 microserver kernel: [76180.035250] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Mar  1 19:51:08 microserver kernel: [76180.035251] CR2: 00000ffe09da5000 CR3: 00000001b1e0a004 CR4: 00000000000626e0
Mar  1 19:51:08 microserver kernel: [76180.035252] Call Trace:
Mar  1 19:51:08 microserver kernel: [76180.035255]  <IRQ>
Mar  1 19:51:08 microserver kernel: [76180.035259]  ? pfifo_fast_enqueue+0x150/0x150
Mar  1 19:51:08 microserver kernel: [76180.035264]  call_timer_fn+0x32/0x130
Mar  1 19:51:08 microserver kernel: [76180.035267]  __run_timers.part.0+0x180/0x280
Mar  1 19:51:08 microserver kernel: [76180.035270]  ? timerqueue_add+0x68/0xb0
Mar  1 19:51:08 microserver kernel: [76180.035272]  ? enqueue_hrtimer+0x3d/0x90
Mar  1 19:51:08 microserver kernel: [76180.035277]  ? recalibrate_cpu_khz+0x10/0x10
Mar  1 19:51:08 microserver kernel: [76180.035279]  ? ktime_get+0x3e/0xa0
Mar  1 19:51:08 microserver kernel: [76180.035282]  run_timer_softirq+0x2a/0x50
Mar  1 19:51:08 microserver kernel: [76180.035285]  __do_softirq+0xe1/0x2d6
Mar  1 19:51:08 microserver kernel: [76180.035288]  ? hrtimer_interrupt+0x13b/0x220
Mar  1 19:51:08 microserver kernel: [76180.035291]  irq_exit+0xae/0xb0
Mar  1 19:51:08 microserver kernel: [76180.035293]  smp_apic_timer_interrupt+0x7b/0x140
Mar  1 19:51:08 microserver kernel: [76180.035296]  apic_timer_interrupt+0xf/0x20
Mar  1 19:51:08 microserver kernel: [76180.035297]  </IRQ>
Mar  1 19:51:08 microserver kernel: [76180.035301] RIP: 0010:cpuidle_enter_state+0xc2/0x450
Mar  1 19:51:08 microserver kernel: [76180.035303] Code: 66 90 31 ff e8 ff aa 80 ff 80 7d c7 00 74 17 9c 58 66 66 90 66 90 f6 c4 02 0f 85 65 03 00 00 31 ff e8 e2 16 87 ff fb 66 66 90 <66> 66 90 45 85 ed 0f 88 8f 02 00 00 49 63 cd 4c 8b 7d d0 4c 2b 7d
Mar  1 19:51:08 microserver kernel: [76180.035304] RSP: 0018:ffffb90fc0083e38 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
Mar  1 19:51:08 microserver kernel: [76180.035306] RAX: ffff8eaa7aa6adc0 RBX: ffffffffa1b59f20 RCX: 000000000000001f
Mar  1 19:51:08 microserver kernel: [76180.035307] RDX: 0000000000000000 RSI: 000000003a5062a9 RDI: 0000000000000000
Mar  1 19:51:08 microserver kernel: [76180.035309] RBP: ffffb90fc0083e78 R08: 000045490beebd96 R09: 0000000000000001
Mar  1 19:51:08 microserver kernel: [76180.035310] R10: ffff8eaa7aa69ac0 R11: ffff8eaa7aa69aa0 R12: ffff8eaa7aa76100
Mar  1 19:51:08 microserver kernel: [76180.035311] R13: 0000000000000004 R14: 0000000000000004 R15: ffff8eaa7aa76100
Mar  1 19:51:08 microserver kernel: [76180.035315]  ? cpuidle_enter_state+0xa1/0x450
Mar  1 19:51:08 microserver kernel: [76180.035317]  cpuidle_enter+0x2e/0x40
Mar  1 19:51:08 microserver kernel: [76180.035320]  call_cpuidle+0x23/0x40
Mar  1 19:51:08 microserver kernel: [76180.035322]  do_idle+0x1dd/0x270
Mar  1 19:51:08 microserver kernel: [76180.035325]  cpu_startup_entry+0x20/0x30
Mar  1 19:51:08 microserver kernel: [76180.035328]  start_secondary+0x167/0x1c0
Mar  1 19:51:08 microserver kernel: [76180.035332]  secondary_startup_64+0xa4/0xb0
Mar  1 19:51:08 microserver kernel: [76180.035334] ---[ end trace c6c9647fa3c4f2b9 ]---
Mar  1 19:51:08 microserver kernel: [76180.035340] tg3 0000:03:00.0 eno1: transmit timed out, resetting
Mar  1 19:51:09 microserver kernel: [76181.303504] tg3 0000:03:00.0 eno1: 0x00000000: 0x165f14e4, 0x00100446, 0x02000000, 0x00800010
Mar  1 19:51:09 microserver kernel: [76181.303545] tg3 0000:03:00.0 eno1: 0x00000010: 0xfabf000c, 0x00000000, 0xfabe000c, 0x00000000


and then periodic:

Mar  1 19:51:09 microserver kernel: [76181.408878] tg3 0000:03:00.0 eno1: 0x00007030: 0x00020000, 0x00004af8, 0x00190030, 0x00000000
Mar  1 19:51:09 microserver kernel: [76181.409189] tg3 0000:03:00.0 eno1: 0: Host status block [00000001:000000f4:(0000:00ca:0000):(0000:00d3)]
Mar  1 19:51:09 microserver kernel: [76181.409512] tg3 0000:03:00.0 eno1: 0: NAPI info [000000f4:000000f4:(00c0:00d3:01ff):0000:(038f:0000:0000:0000)]
Mar  1 19:51:09 microserver kernel: [76181.409853] tg3 0000:03:00.0 eno1: 1: Host status block [00000001:00000010:(0000:0000:0000):(0a9a:0000)]
Mar  1 19:51:09 microserver kernel: [76181.410201] tg3 0000:03:00.0 eno1: 1: NAPI info [00000010:00000010:(0000:0000:01ff):0a9a:(029a:029a:0000:0000)]
Mar  1 19:51:09 microserver kernel: [76181.410563] tg3 0000:03:00.0 eno1: 2: Host status block [00000001:00000006:(0bd7:0000:0000):(0000:0000)]
Mar  1 19:51:09 microserver kernel: [76181.410937] tg3 0000:03:00.0 eno1: 2: NAPI info [00000000:00000000:(0000:0000:01ff):0bd1:(03d1:03d1:0000:0000)]
Mar  1 19:51:09 microserver kernel: [76181.411331] tg3 0000:03:00.0 eno1: 3: Host status block [00000001:00000039:(0000:0000:0000):(0000:0000)]
Mar  1 19:51:09 microserver kernel: [76181.411943] tg3 0000:03:00.0 eno1: 3: NAPI info [00000038:00000038:(0000:0000:01ff):0dc5:(05c5:05c5:0000:0000)]
Mar  1 19:51:09 microserver kernel: [76181.412610] tg3 0000:03:00.0 eno1: 4: Host status block [00000001:0000009b:(0000:0000:0697):(0000:0000)]
Mar  1 19:51:09 microserver kernel: [76181.413282] tg3 0000:03:00.0 eno1: 4: NAPI info [0000009b:0000009b:(0000:0000:01ff):0697:(0697:0697:0000:0000)]
Mar  1 19:51:09 microserver kernel: [76181.542591] tg3 0000:03:00.0 eno1: Link is down
Mar  1 19:51:09 microserver kernel: [76181.667610] br0: port 1(eno1) entered disabled state
Mar  1 19:51:13 microserver kernel: [76185.280312] tg3 0000:03:00.0 eno1: Link is up at 1000 Mbps, full duplex
Mar  1 19:51:13 microserver kernel: [76185.280315] tg3 0000:03:00.0 eno1: Flow control is on for TX and on for RX
Mar  1 19:51:13 microserver kernel: [76185.280316] tg3 0000:03:00.0 eno1: EEE is enabled
Mar  1 19:51:13 microserver kernel: [76185.280342] br0: port 1(eno1) entered blocking state
Mar  1 19:51:13 microserver kernel: [76185.280347] br0: port 1(eno1) entered forwarding state
Mar  1 19:51:23 microserver kernel: [76195.907151] tg3 0000:03:00.0 eno1: transmit timed out, resetting
Mar  1 19:51:25 microserver kernel: [76197.174266] tg3 0000:03:00.0 eno1: 0x00000000: 0x165f14e4, 0x00100446, 0x02000000, 0x00800010
Mar  1 19:51:25 microserver kernel: [76197.174972] tg3 0000:03:00.0 eno1: 0x00000010: 0xfabf000c, 0x00000000, 0xfabe000c, 0x00000000


Switch is a unmaged netgear gigabit SOHO switch.