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Showing posts from March, 2022

Private VLAN on Arista EOS Switch (How ISP isolates traffic between subscribers)

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The other day, I was looking at the arp table entry for my home router and found a funny thing going on - $ show arp Address                 HWtype    HWaddress              Iface 10.10.10.1              ether        04-96-AF-EF-C6-53    eth0 10.10.10.10            ether        04-96-AF-EF-C6-53    eth0 Above arp table is an example hiding the actual IP addresses and MAC addresses. Here my IP address is let's say - 10.10.10.50/24 and GW is 10.10.10.1 . Now the question comes why another subscriber of the ISP in the same subnet (10.10.10.10) also have same mac address as my GW (04-96-AF-EF-C6-53). We are in the same IP network/VLAN (ISP definitely configured those), but my router cannot see the actual MAC address of other devices in the network. The reason is that my ISP is i...