[SOLVED] DHCP client in vm not working on tagged bond

Feb 10, 2024
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Evaluating proxmox as a possible replacement for vmware in our environment. Currently using 8.1 without subscription for the evaluation process.

All firewalls disabled (datacenter, node, and vm levels).
A vm on the basic 1gb untagged port vmbr0 works fine for obtaining a dhcp address. The dhcp server is outside the proxmox host.

vms with statically assigned IPs work fine on various interfaces such as vmbr1004, vmbr1002, vmb1013, vmb1015, etc...

Doing tcpdump (various vlans tested, but 1013 for example), on the host, the dhcp request (x4, assuming because of broadcast) and reply show on bond10, bond10.1013, and vmbr1013.
However, doing tcpdump inside the vm, the request goes out but the reply is never received. The guest does see other broadcast traffic, such as arp requests and STP traffic. If an IP is statically assigned an IP, then everything appears to be working fine.

Any suggestions? The interfaces file is attached. The guest is using a paravirtual interface.
 

Attachments

  • interfaces.txt
    2.4 KB · Views: 0
After more searching, and testing... (honestly, I searched these forums first for a solution, and only found others with similar problem but not a working solution...)
adding
bridge-ageing 0
under each iface vmbr#### resolved the issue. Solution was mentioned here:
https://forum.proxmox.com/threads/p...zation-do-not-apply-dhcpoffer-replies.128387/

Seems like this should either be the default, or at least be configurable via the gui. On the plus side, modifying the interfaces file directly, the change is kept if you make other network changes via the gui.
 

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