I have installed GNS3 and trying to enable on Router as mentioned above depict.
How to enabled DHCP on Cisco router R3 ?
Best Answer
Move to configuration mode by typing this (you exclude address that you don't want the DHCP to assign to any device, e.g. printers, static
IP addresses, etc.):
Router# config t
Router(conf)# ip dhcp excluded-adress <excluded address list>
Now you have to set up a pool, a pool of IP addresses:
Router(conf-dhcp)# ip dhcp pool <pool name>
now remember the pool is all possible host of the network addresses that you will assign here:
Router(conf-dhcp)# network <network> <mask or /length>
now you set up the default gateway (which in this case is itself):
DHCP is a link-local protocol. (broadcast) For it to span networks (broadcast domains, the internet, etc.) there has to be a relay-agent. (or more than one) That agent listens for requests (unicast and broadcast) and transmits them on to some other server. In theory that server can be anywhere, but some (many?) DHCP servers aren't happy getting requests from non-local agents. (like the DHCP server in windows 2000) Also note, there is a maximum size for DHCP requests; each relay adds to the packet.
I would recommend packet captures. (debug ip packet, with an ACL defined to catch dhcp) As your router(s) aren't a DHCP server or relay-agent, debug ip dhcp isn't going to get anywhere.
Finally solved the problem!!
So I was facing problem due to loss of information in the dhcp binding table. In short the subscriber id automatically generated would not match my reservations. Here are some examples:
Best Answer
Move to configuration mode by typing this (you exclude address that you don't want the DHCP to assign to any device, e.g. printers, static IP addresses, etc.):
Now you have to set up a pool, a pool of IP addresses:
now remember the pool is all possible host of the network addresses that you will assign here:
now you set up the default gateway (which in this case is itself):
The line above excludes the default gateway's IP address from the pool.
Setting up DNS server's IP address to exclude that too:
Now if you want to check DHCP clients, simply type: