nic：何か邪悪なことが起こった！ ffff
Debian Stretch（9.7）を使用してGNU/Linuxルーターを構成しています。サーバーを再起動する前に、あるインターフェースから別のインターフェースへのトラフィックはすべて正常に機能していましたが、その後、次のようなメッセージ（tty）を受け取りました。
enp1s6: Something Wicked happened! ffff.
テスト目的で、同じスイッチと同じネットワーク上にホストがあり、基本的に、ルーターのLANがエコー要求に応答していません。
サーバーに関するいくつかの情報を示します。
kernel.log
Jan 25 08:58:02 server001 kernel: [25060.494127] enp1s6: Link changed:
Jan 25 08:58:02 server001 kernel: [25060.494127] 100Mbps, half duplex
Jan 25 08:58:02 server001 kernel: [25060.494254] enp1s6: Something Wicked happened! ffff.
Jan 25 08:58:02 server001 kernel: [25060.497338] enp1s6: Link up
Jan 25 08:58:02 server001 kernel: [25060.497557] enp1s6: Link changed:
Jan 25 08:58:02 server001 kernel: [25060.497557] 100Mbps, full duplex
Jan 25 08:58:02 server001 kernel: [25060.499986] enp1s6: Link up
Jan 25 08:58:02 server001 kernel: [25060.500206] enp1s6: Link changed:
Jan 25 08:58:02 server001 kernel: [25060.500206] 100Mbps, full duplex
Jan 25 08:58:02 server001 kernel: [25060.500447] enp1s6: Link up
Jan 25 08:58:02 server001 kernel: [25060.500667] enp1s6: Link changed:
Jan 25 08:58:02 server001 kernel: [25060.500667] 100Mbps, full duplex
Jan 25 08:58:02 server001 kernel: [25060.500895] enp1s6: Link up
Jan 25 08:58:02 server001 kernel: [25060.501114] enp1s6: Link changed:
Jan 25 08:58:02 server001 kernel: [25060.501114] 10Mbps, full duplex
Jan 25 08:58:02 server001 kernel: [25060.501341] enp1s6: Link up
Jan 25 08:58:02 server001 kernel: [25060.501559] enp1s6: Link changed:
Jan 25 08:58:02 server001 kernel: [25060.501559] 100Mbps, full duplex
Jan 25 08:58:02 server001 kernel: [25060.503985] enp1s6: Link up
Jan 25 08:58:02 server001 kernel: [25060.504204] enp1s6: Link changed:
Jan 25 08:58:02 server001 kernel: [25060.504204] 100Mbps, full duplex
Jan 25 08:58:02 server001 kernel: [25060.504326] enp1s6: Something Wicked happened! ffff.
Jan 25 08:58:02 server001 kernel: [25060.529009] enp1s6: Link up
Jan 25 08:58:02 server001 kernel: [25060.529229] enp1s6: Link changed:
Jan 25 08:58:02 server001 kernel: [25060.529230] 100Mbps, full duplex
Jan 25 08:58:02 server001 kernel: [25060.529484] enp1s6: Link up
Jan 25 08:58:02 server001 kernel: [25060.529732] enp1s6: Link changed:
Jan 25 08:58:02 server001 kernel: [25060.529735] 100Mbps, full duplex
Jan 25 08:58:02 server001 kernel: [25060.531075] enp1s6: Link up
Jan 25 08:58:02 server001 kernel: [25060.531295] enp1s6: Link changed:
Jan 25 08:58:02 server001 kernel: [25060.531296] 100Mbps, half duplex
Jan 25 08:58:02 server001 kernel: [25060.531531] enp1s6: Link up
Jan 25 08:58:02 server001 kernel: [25060.531751] enp1s6: Link changed:
Jan 25 08:58:02 server001 kernel: [25060.531751] 100Mbps, full duplex
Jan 25 08:58:02 server001 kernel: [25060.531977] enp1s6: Link up
Jan 25 08:58:02 server001 kernel: [25060.532196] enp1s6: Link changed:
Jan 25 08:58:02 server001 kernel: [25060.532196] 100Mbps, half duplex
Jan 25 08:58:02 server001 kernel: [25060.532422] enp1s6: Link up
Jan 25 08:58:02 server001 kernel: [25060.532642] enp1s6: Link changed:
Jan 25 08:58:02 server001 kernel: [25060.532642] 100Mbps, full duplex
Jan 25 08:58:02 server001 kernel: [25060.532869] enp1s6: Link up
Jan 25 08:58:02 server001 kernel: [25060.533089] enp1s6: Link changed:
Jan 25 08:58:02 server001 kernel: [25060.533090] 100Mbps, full duplex
Jan 25 08:58:02 server001 kernel: [25060.533214] enp1s6: Something Wicked happened! ffff.
lspci（nics）：enp0s7 + enp1s6
00:07.0 Bridge: NVIDIA Corporation MCP61 Ethernet (rev a2)
Subsystem: Gigabyte Technology Co., Ltd MCP61 Ethernet
Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 24, NUMA node 0
Memory at fe02d000 (32-bit, non-prefetchable) [size=4K]
I/O ports at f000 [size=8]
Capabilities: [44] Power Management version 2
Capabilities: [50] MSI: Enable+ Count=1/8 Maskable+ 64bit+
Capabilities: [6c] HyperTransport: MSI Mapping Enable- Fixed+
Kernel driver in use: forcedeth
Kernel modules: forcedeth
01:06.0 Ethernet controller: Sundance Technology Inc / IC Plus Corp IC Plus IP100A Integrated 10/100 Ethernet MAC + PHY (rev 31)
Flags: bus master, medium devsel, latency 0, IRQ 16, NUMA node 0
I/O ports at b000 [size=128]
Memory at fde00000 (32-bit, non-prefetchable) [size=512]
[virtual] Expansion ROM at fdf00000 [disabled] [size=64K]
Capabilities: [50] Power Management version 2
Kernel driver in use: sundance
Kernel modules: sundance
ethtool
Settings for enp0s7:
Supported ports: [ MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supported pause frame use: No
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: Yes
Speed: 100Mb/s
Duplex: Full
Port: MII
PHYAD: 3
Transceiver: external
Auto-negotiation: on
Supports Wake-on: g
Wake-on: d
Link detected: yes
Settings for enp1s6:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Supported pause frame use: No
Supports auto-negotiation: Yes
Advertised link modes: Not reported
Advertised pause frame use: No
Advertised auto-negotiation: No
Speed: 100Mb/s
Duplex: Full
Port: MII
PHYAD: 0
Transceiver: internal
Auto-negotiation: off
Supports Wake-on: pg
Wake-on: d
Current message level: 0x00000001 (1)
drv
Link detected: yes
ethtool統計（enp1s6）
NIC statistics:
tx_multiple_collisions: 26010
tx_single_collisions: 27540
tx_late_collisions: 5100
tx_deferred: 27030
tx_deferred_excessive: 26010
tx_aborted: 6630
tx_bcasts: 27030
rx_bcasts: 27032
tx_mcasts: 5610
rx_mcasts: 27285
ip addr show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope Host lo
valid_lft forever preferred_lft forever
2: enp1s6: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
link/ether 84:16:84:16:84:16 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.1/24 brd 192.168.1.255 scope global enp1s6
valid_lft forever preferred_lft forever
3: enp0s7: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 50:e5:49:64:f6:8b brd ff:ff:ff:ff:ff:ff
inet 192.168.0.12/24 brd 192.168.0.255 scope global enp0s7
valid_lft forever preferred_lft forever
lsmod
Module Size Used by
ip6table_filter 16384 0
ip6_tables 28672 1 ip6table_filter
xt_conntrack 16384 2
nf_conntrack_netlink 36864 0
nfnetlink 16384 6 nf_conntrack_netlink
iptable_filter 16384 1
ipt_MASQUERADE 16384 1
nf_nat_masquerade_ipv4 16384 1 ipt_MASQUERADE
iptable_nat 16384 1
nf_conntrack_ipv4 16384 3
nf_defrag_ipv4 16384 1 nf_conntrack_ipv4
nf_nat_ipv4 16384 1 iptable_nat
nf_nat 24576 2 nf_nat_masquerade_ipv4,nf_nat_ipv4
nf_conntrack 114688 6 nf_conntrack_ipv4,nf_conntrack_netlink,nf_nat_masquerade_ipv4,xt_conntrack,nf_nat_ipv4,nf_nat
snd_hda_codec_realtek 90112 1
snd_hda_codec_generic 69632 1 snd_hda_codec_realtek
edac_mce_AMD 28672 0
edac_core 57344 0
kvm 598016 0
evdev 24576 2
ppdev 20480 0
serio_raw 16384 0
nouveau 1556480 1
joydev 20480 0
snd_hda_intel 36864 0
mxm_wmi 16384 1 nouveau
snd_hda_codec 135168 3 snd_hda_intel,snd_hda_codec_generic,snd_hda_codec_realtek
wmi 16384 2 mxm_wmi,nouveau
snd_hda_core 86016 4 snd_hda_intel,snd_hda_codec,snd_hda_codec_generic,snd_hda_codec_realtek
video 40960 1 nouveau
snd_hwdep 16384 1 snd_hda_codec
ttm 98304 1 nouveau
drm_kms_helper 155648 1 nouveau
drm 360448 4 nouveau,ttm,drm_kms_helper
snd_pcm 110592 3 snd_hda_intel,snd_hda_codec,snd_hda_core
irqbypass 16384 1 kvm
sg 32768 0
pcspkr 16384 0
k10temp 16384 0
parport_pc 28672 0
parport 49152 2 parport_pc,ppdev
i2c_algo_bit 16384 1 nouveau
button 16384 1 nouveau
snd_timer 32768 1 snd_pcm
snd 86016 7 snd_hda_intel,snd_hwdep,snd_hda_codec,snd_timer,snd_hda_codec_generic,snd_hdacodec_realtek,snd_pcm
soundcore 16384 1 snd
acpi_cpufreq 20480 0
ip_tables 24576 3 iptable_filter,iptable_nat
x_tables 36864 6 ip_tables,iptable_filter,ipt_MASQUERADE,ip6table_filter,xt_conntrack,ip6_tables
autofs4 40960 2
ext4 585728 2
crc16 16384 1 ext4
jbd2 106496 1 ext4
fscrypto 28672 1 ext4
ecb 16384 0
glue_helper 16384 0
lrw 16384 0
gf128mul 16384 1 lrw
ablk_helper 16384 0
cryptd 24576 1 ablk_helper
aes_x86_64 20480 1
mbcache 16384 3 ext4
raid10 49152 0
raid456 106496 0
async_raid6_recov 20480 1 raid456
async_memcpy 16384 2 raid456,async_raid6_recov
async_pq 16384 2 raid456,async_raid6_recov
async_xor 16384 3 async_pq,raid456,async_raid6_recov
async_tx 16384 5 async_xor,async_pq,raid456,async_memcpy,async_raid6_recov
xor 24576 1 async_xor
raid6_pq 110592 3 async_pq,raid456,async_raid6_recov
libcrc32c 16384 1 raid456
crc32c_generic 16384 3
raid0 20480 0
multipath 16384 0
linear 16384 0
raid1 36864 1
md_mod 135168 6 raid1,raid10,multipath,linear,raid0,raid456
sd_mod 49152 7
hid_generic 16384 0
usbhid 53248 0
hid 122880 2 hid_generic,usbhid
ata_generic 16384 0
ohci_pci 16384 0
psmouse 135168 0
sata_nv 28672 5
forcedeth 69632 0
ehci_pci 16384 0
libata 249856 2 ata_generic,sata_nv
ohci_hcd 53248 1 ohci_pci
ehci_hcd 81920 1 ehci_pci
scsi_mod 225280 3 sd_mod,libata,sg
usbcore 253952 5 usbhid,ehci_hcd,ohci_pci,ohci_hcd,ehci_pci
sundance 32768 0
mii 16384 1 sundance
usb_common 16384 1 usbcore
i2c_nforce2 16384 0
推測は？
お待ちください。私は元SysAdmin（数年前）で、現在はソフトウェア開発者です。
あなたのサンダンス10/100 NICは古すぎる、おそらく古すぎるようです...
https://bugzilla.redhat.com/show_bug.cgi?id=74897 を参照してください（ギガビットルーターに接続すると、f16 Sundance 10/100イーサネットモジュールがクラッシュします）
あなたのethtool出力によると、enp1s6が自動ネゴシエーションをサポートしていると報告していないことがわかりました。接続しているデバイス/ポートでも無効になっていますか？可能であれば、接続しているデバイスを調整して、自動ネゴシエーションを有効にします。そのデバイスにアクセスできない場合、またはデバイスを変更したくない場合は、enp1s6の速度/デュプリックスを強制する必要がある場合があります。