网络常见问题

sysctl net.ipv4.tcp_{,r,w}mem net.core.rmem_{default,max} net.core.wmem_{default,max} net.core.optmem_max

net.ipv4.tcp_wmem= 10240 88064 12582912
net.ipv4.tcp_rmem= 10240 88064 12582912
net.core.rmem_max= 12582912

net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_timestamps = 1
net.ipv4.tcp_sack = 1
net.ipv4.tcp_no_metrics_save = 1
net.core.netdev_max_backlog = 5000

iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE
iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to-source 192.168.8.2

ifconfig eth0:0 192.168.1.2 netmask 255.255.255.0
# 对等语法
ip addr add 192.168.1.2/24 dev eth0 label eth0:0

# 看不到进程
sudo ss -lutp | grep 8472
# -e 显示扩展信息 - 会看到在 cgroup 里 cgroup:/k3s
sudo ss -lutpe | grep 8472

# 获取 8472 对应的 inode - 然后可以用过 inode 反查
INODE=$(sudo ss -lutpe | grep 8472 | grep -Eo 'ino:\d+' | grep -Eo '\d+')

# lsof 看不到 PORT
sudo lsof 2>/dev/null -nPi UDP | head

lspci | grep Mel
ip li show eth4
lsmod | grep mlx | sort

sudo dmesg -t | grep mlx
sudo lspci -vv -s 04:00.0

ethtool --show-priv-flags eth4

Mellanox Technologies MT26448
Part number: MNPA19-XTR

# 没问题
# Broadcom Inc. and subsidiaries NetXtreme II BCM57810 10 Gigabit Ethernet
# 有问题
# Mellanox Technologies MT26448 [ConnectX EN 10GigE, PCIe 2.0 5GT/s]
lspci | grep 'Ethernet controller'

ethtool eth4

Supported ports: [ FIBRE ]
Supported link modes:   10000baseT/Full
Supported pause frame use: No
Supports auto-negotiation: No
Supported FEC modes: Not reported
Advertised link modes:  10000baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: No
Advertised FEC modes: Not reported
Speed: 10000Mb/s
Duplex: Full
Auto-negotiation: off
Port: FIBRE
PHYAD: 0
Transceiver: internal
Supports Wake-on: d
Wake-on: d
Current message level: 0x00000014 (20)
                        link ifdown
Link detected: yes

ethtool -s eth4 autoneg on

netlink error: link settings update failed
netlink error: Invalid argument

Supported ports: [ FIBRE ]
Supported link modes:   1000baseT/Full
                        10000baseT/Full
Supported pause frame use: Symmetric Receive-only
Supports auto-negotiation: No
Supported FEC modes: Not reported
Advertised link modes:  10000baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: No
Advertised FEC modes: Not reported
Speed: 10000Mb/s
Duplex: Full
Auto-negotiation: off
Port: Direct Attach Copper
PHYAD: 1
Transceiver: internal
Supports Wake-on: g
Wake-on: g
Current message level: 0x00000000 (0)

Link detected: yes

ethtool -s $IFACE wol g

wol p|u|m|b|a|g|s|d...
          Set Wake-on-LAN options.  Not all  devices  support  this.   The
          argument  to  this  option  is a string of characters specifying
          which options to enable.
          p  Wake on phy activity
          u  Wake on unicast messages
          m  Wake on multicast messages
          b  Wake on broadcast messages
          a  Wake on ARP
          g  Wake on MagicPacket(tm)
          s  Enable SecureOn(tm) password for MagicPacket(tm)
          d  Disable (wake on nothing).  This option clears  all  previous
             options.