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DHCP on a Cisco 2900, static mapping (continued)

roncro
Level 3
Level 3

Hello, this might (probably is) a rookie question;

 

I used to have an RV320 small business router, and that was set up pretty straight forward.

All IP addresses were static, using MAC binding, in mainly 2 different subnets (192.168.1.x and 192.168.2.0 (and there were a few in 192.168.3.x for testing).

 

Anyway, it seemed one list on that thing (although it used a web interface) So I figured:

 

On the Cisco 2900 if I make one pool, with all static bindings in it, I probably can accomplish the same thing that was working on the RV320, and then move forward from that situation later..

So I created a static binding file with those IP and MAC addresses.

 

here's what I did, and since it  is not working it probably is incomplete or wrong:

 

enable

conf t

service dhcp

ip dhcp pool EVERYTHING-POOL

default-router 192.168.1.1             ! this is the router itself

dns-server 192.168.1.1                  ! the dns service on the same router

ip dhcp excluded-address 192.168.1.1 192.168.1.10    !  shouldn't need this; everything is static with MAC IP binding

origin file tftp://192.168.2.8/dhcp/static-binding.txt

exit

 

no service dhcp

service dhcp

 

the static-binding.txt has ip addresses in bot the 192.168.1.0 and 192.168.2.0 subnets.

 

What I see happening is that, some nodes consistently get the correct IP address.  Some nodes don't get any address at all and the majority of nodes get 'random' addresses  in the 192.168.0.0 net (192.168.0.60, 192.168.0.37 etc.)

 

any ideas/hints on how to tackle this?

 

thanks,

 

Ron

 

1 Reply 1

roncro
Level 3
Level 3

update;

 

I wonder if dhcp is actually running;

 

when I do a "sudo nmap --script broadcast-dhcp-discover 192.168.1.1" on a host in the network, I should see something on port 67 if there was a dhcp server listening, right?

what I see is this;

$ sudo nmap --script broadcast-dhcp-discover 192.168.1.1
Starting Nmap 7.70 ( https://nmap.org ) at 2020-04-21 00:46 MDT
Nmap scan report for cr.localdomain (192.168.1.1)
Host is up (0.0035s latency).
Not shown: 995 closed ports
PORT STATE SERVICE
22/tcp open ssh
23/tcp open telnet
53/tcp open domain
80/tcp open http
443/tcp open https
MAC Address: 54:A2:74:XX:YY:ZZ (Cisco Systems)

Nmap done: 1 IP address (1 host up) scanned in 12.97 seconds

 

How can I check it is actually running (I did a 'service dhcp')  and if it is listening on the LAN interface?

 

thanks,

 

Ron