We have 2 Routers.The Remote Router(2600) sends the DHCP relay and forwarding packets to the Main Router(4700M).The DHCP forwarding packet has a Gateway IP address of 0.0.0.0.When the packets are relayed with special processing,why do they get forwarded also with no special processing.Is there a way we can block the DHCP forwarded packets alone going from remote site router to Main site router.Is there a selective access-list for doing that.
Routers do not, by default, forward DHCP requests. ip-helper is most surely configured on your remote router, unless your bridging. Can you just remove or change this ip-helper to suit your needs? Access-lists to stop these might very well effect other things that you might want to pass. If you really want to use an ACL you can deny ip from the primary ip address of the remote router's interface, which is used to encapsulate the DHCP request (DISCOVER)..
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...