为什么 8 根线全通协商出来百兆?

移动师傅说单元楼入户时候用的老线，后来改光纤但我们小区线管老化穿不动所以各家入户还是用的以前的双绞线，每个单元一个交换机用 ont 到局端，PPPOE 拨号

他现场做了水晶头，从我家到单元的网线柜里的交换机用测线仪测了 1-8 全部都是通的

我自己的测线仪测了也是 1-8 全通，但是 AX3000 刷了 Openwrt 接上 WAN 用 ethtool 看就是 100mbps

师傅测了说 96Mbps 也差不多 100 ，别家也是一样接的人家路由上都是 1000Mbps,是你家路由不行得换,就溜了

我看了下楼下交换机确实支持 1000Mbps ，是研华的 EKI3728,所有口都支持 1000Mbps ，就只有两个口是橘黄灯(我家是其中一个)其他都是绿灯

回来上 openwrt 看了下

root@redmi:~# ethtool eth1
Settings for eth1:
        Supported ports: [ TP MII ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Supported pause frame use: Symmetric Receive-only
        Supports auto-negotiation: Yes
        Supported FEC modes: Not reported
        Advertised link modes:  10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Advertised pause frame use: Symmetric Receive-only
        Advertised auto-negotiation: Yes
        Advertised FEC modes: Not reported
        Link partner advertised link modes:  10baseT/Half 10baseT/Full
                                             100baseT/Half 100baseT/Full
        Link partner advertised pause frame use: Symmetric
        Link partner advertised auto-negotiation: Yes
        Link partner advertised FEC modes: Not reported
        Speed: 100Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 0
        Transceiver: external
        Auto-negotiation: on
        MDI-X: Unknown
        Current message level: 0x000000ff (255)
                               drv probe link timer ifdown ifup rx_err tx_err
        Link detected: yes

中间这里这个 Link partner advertised link modes 看起来是对端宣告了最高 100baseT?跟这个有关系吗？