Do you mean (1) if the router is acting as a bootp or DHCP server? Or (2) if bootp or DHCP broadcasts received on one interface are being forwarded to a remote server on another interface?
Here's an answer to (2).
Look at the startup-config and running-config. If "ip helper-address" command is listed under a particular interface, then bootp broadcasts heard on that interface should be forwarded to the specified IP address.
The "ip helper-address" command forwards the following UDP ports by default:
time (37)
tacacs (49)
dns or domain (53)
bootp server or bootps (67)
bootp client or bootpc (68)
tftp (69)
netbios name service or netbios-ns (137)
netbios datagram service or netbios-dgm (138)
DHCP uses the same ports as bootp.
A sample configuration that supports forwarding only DHCP requests heard on two interfaces to a DHCP server (192.168.0.10) on a third interface follows. Note how forwarding (or blocking forwarding) of the other default protocols is done at the system level; while the helper-address is configured interface by interface.
interface ethernet0/0
description This is the subnet where the DHCP server lives
ip address 192.168.0.1 255.255.255.0
!
interface ethernet1/0
description This is where some DHCP clients live and need DHCP forwarded
ip address 192.168.1.1 255.255.255.0
ip helper-address 192.168.0.10
!
interface ethernet2/0
description This is where other DHCP clients live and need DHCP forwarded
ip address 192.168.2.1 255.255.255.0
ip helper-address 192.168.0.10
!
no ip forward-protocol udp time
no ip forward-protocol udp tacacs
no ip forward-protocol udp domain
no ip forward-protocol udp tftp
no ip forward-protocol udp netbios-ns
no ip forward-protocol udp netbios-dgm
Hope this helps.
