Multiple chrooted dhcp servers for vlans on Linux?

Simon Hobson dhcp1 at
Sat Feb 27 20:11:51 UTC 2016

stevel_isc at wrote:

> I had high hopes since firehol has a helper for dhcp and does appear to be
> setting an accept rule for "udp spt:bootpc dpt:bootps".  
> I've never actually checked to see if dropping the rule would still let dhcp
> function though.

dhcpd uses two routes to/from the network.
For some packets it needs to bypass the network stack because it must handle packets to/from unconfigured clients which are done by local broadcast.
But it also deals with "ordinary" IP packets - renewals with already configured clients, relayed requests from other networks. These definitely go through the network stack outbound, and I think, in bound (but I'm not certain of that).

> At least I'm getting a good education on dhcp and iptables, thank you!


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