记一次kubernetes获取internal Ip错误流程

ip addr

eth0 ip1

eth0:xxx ip2

// 1) Use nodeIP if set (and not "0.0.0.0"/"::")

// 2) If the user has specified an IP to HostnameOverride, use it

// 3) Lookup the IP from node name by DNS

// 4) Try to get the IP from the network interface used as default gateway

//

// For steps 3 and 4, IPv4 addresses are preferred to IPv6 addresses

// unless nodeIP is "::", in which case it is reversed.

addrs, _ = net.LookupIP(node.Name)

modprobe nlmon

ip link add nlmon0 type nlmon

ip link set dev nlmon0 up

tcpdump -i nlmon0 -w netlinik.pcap

# 使用nlmon 驱动模块，这个nlmon 驱动模块会注册一个 netlink tap 口，用户态向内核发送 netlink 消息、内核向用户态发送 netlink 消息，报文都会经过这个 tap 口。

Rule 9: Use longest matching prefix.

When DA and DB belong to the same address family (both are IPv6 or

both are IPv4): If CommonPrefixLen(DA, Source(DA)) >

CommonPrefixLen(DB, Source(DB)), then prefer DA. Similarly, if

CommonPrefixLen(DA, Source(DA)) < CommonPrefixLen(DB, Source(DB)),

then prefer DB.