For a [corporate] router that is locked down... has MAC filtering and whitelisting and all that, such that plugging in any new server on an open port will not receive a DHCP ipv4 address (but it will get a link light).

For an existing server that is whitelisted and fully working, call it server A, it has a quad-port nic. eth0 is wan reaching the proxy and out to the world; a yum update works on server A.

If I take server B, and network it to eth1 on server A, and then on server A bridge eth0 and eth1 will I be able to do a yum update on server B ? Will the router and whatever else recognize the different MAC address of server B and prohibit it network access?

  • 1
    a bridge passes garbage along, so you probably instead want NAT
    – thrig
    Aug 30, 2022 at 21:54
  • It's either routing+NAT as already suggested, or routing+proxy ARP if you want to keep a different visible IP address for server B while still using Server A's MAC address and IP address is not enforced by the router. In any case this precludes DHCP. Any feedback from these comments?
    – A.B
    Sep 24, 2022 at 10:45
  • It's also possible to do NAT in a bridge on the Ethernet bridge MAC address rather than NAT in a router on the IP address, but that would be very awkward because of all the tiny details to address. For all intents and purporses, proxy ARP would achieve the same in a cleaner way.
    – A.B
    Sep 24, 2022 at 10:55


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