reject dhclient offer from wrong subnet
Hi list
My router and my docsys modem power on at the same time. the modem is
handing out dhcp offers of 192.168.100/24 . I assume they are meant for
internal set up purposes and dhclient on my router should not catch or
respond to them. Only the final offer after modem bootup has completed
does contain the WAN subnet and a lease time of 4 hours.
Can I configure dhclient on my router to discard lease offers from a
certain subnet? I could also try to match the lease time, the
192.168.100/24 lease time is only several seconds (!!) short, the real
one will be 4 hours or more and come with a valid WAN subnet mask.
I never had this problem before, so I don't know how to change
dhclient's behaviour to a bogus lease offer.
Maybe iptables could assist and block multicast traffic from/to the
wrong subnet? I'm not sure I would still get the actual WAN lease then.
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