Netgate Discussion Forum
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Search
    • Register
    • Login

    Bridged VLAN not passing parent MAC in ARP response

    Scheduled Pinned Locked Moved L2/Switching/VLANs
    2 Posts 1 Posters 488 Views
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • F
      follysuperscript
      last edited by follysuperscript

      Hello,

      Thank you for this incredible software package. I use it constantly and appreciate all the hard work that goes into it. I've spent enough time searching these forums to know that questions related to bridging often elicit frustrated responses. Questions related to VLANs and bridging at the same time garner even more frustrated responses. So it is with great hesitation I explain my issue.

      I have a VLAN interface bridged...
      The parent bridge is assigned an IP address and a MAC address.
      The VLAN interface has no configured IP, the MAC section is grayed out, stating "The MAC address of a VLAN interface must be set on its parent interface"
      Related system tunables have been set
      net.link.bridge.pfil_member to 0.
      net.link.bridge.pfil_bridge to 1.

      When I boot up a host in this bridge, it gets an IP address, ARPs for the gateway and the gateway responds with the bridge MAC address. No further uni-cast traffic makes it to the bridge or VLAN interface according packet captures.

      If I change the bridge address (dangerously?) to the VLAN member's parent (duplicate) mac, all traffic starts flowing. No firewall issues. It seems like a L2 MAC / ARP issue.

      It seems that the MAC address of the VLAN interface is what is needed to for host communications to flow, but the bridge interface MAC address gets stored in the host's ARP cache and doesn't work.

      Any ideas on how to get this to work without a duplicate MAC? I'm sure there is a simple network concept that I'm not aware of that can resolve this (please don't say "buy a switch", although I'm sure it will be comment 1).

      Any help appreciated!

      1 Reply Last reply Reply Quote 0
      • F
        follysuperscript
        last edited by

        After thinking about how MAC addresses work on a switch, I replicated the MAC across all bridge members and the bridge itself, and things began working!

        1 Reply Last reply Reply Quote 0
        • mgiM mgi referenced this topic on
        • mgiM mgi referenced this topic on
        • First post
          Last post
        Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.