<div>
John - DHCP range is 100-254, so 155 available IPs for dynamic use. I have assigned the majority of my static IPs in the 10-99 range, .11, .21, .22, .23, .30, etc. Some are assigned in the 100-254 range, but very few. When you say &quot;Set up MAC address filtering to correspond.&quot; I assume you are referring to the Static IP section under DHCP Setup. If so I have that setup for every static IP on my network.<br />
<br />
One thing I don't do is I don't have all of my devices set with the static IP address. I have assumed that if I assign them a static IP through the router, and still leave the device set to retrieve it's DHCP automatically, this will work fine. Do I have a potential problem there? Maybe I need to log into each device I have assigned as static and set the IP there also.<br />
<br />
Fred - I am actually only seeing one list. In the Cisco RV042G I can only view a &quot;Client Table&quot; under the DHCP Status tab. Based on the description of this provided by Cisco, &quot;For all network devices using the DHCP server...,&quot; I am under the impression this is a list of leases. But whether it is a list of leases or a list of active devices it is still quite confusing in that the computer I am actually using is not listed in the list. I am certain it has both a current lease and is active, yet it is not listed.<br />
<br />
As for the lease time, I left that set to the default 1440 minutes. I can certainly lower that to 4 or 8 hours, but it just wasn't something I changed in the original setup. Could it be possible that the unknown MAC addresses had leases on an old IP address, prior to me assigning the static IP, and because the lease is currently not dropped for 24 hours it is still showing that old lease?
</div>


<div>
I am travelling and will check my own router later but in your above post any given device should be static only or DHCP only. Do not try to mix on the same device. Yes, I think trying to mix will present a problem. Your ranges and practices for static and DHCP on your router are fine and close to my own . That is not likely to be your problem
</div>


<div>
Yes - old leases. &nbsp;Well there are really no &quot;old&quot; leases, just unexpired leases.<br />
<br />
If you are asking: Would reserving an IP for a MAC address have an effect on a current lease to that same MAC address .. well, that's an interesting question. &nbsp;One supposes if you release the ip on the client side and then renew that it would get the reserved IP address. &nbsp;That doesn't mean that the lease for the old IP address would expire though. &nbsp;The lease could remain until it expires. &nbsp;The device won't ask for a renewal of it I shouldn't think. &nbsp;But it may ask for a renewal and one hopes that will flow through the reserved IP function first.<br />
<br />
Then there is the question: Do reserved IP/MAC combinations show up on the list? &nbsp;Some routers call the list &quot;dynamic&quot; so presumably would not.
</div>


<div>
John - I believe one of my main errors here was in how I assigned static IPs through the setup in the router but then was still allowing some of my devices to work off of DHCP. That could be the reason I am seeing some weird things with the devices in the unknown MAC address table. I have changed some of the conflicting devices to have a dedicated IP and they have not shown back up in the unknown MAC address table.<br />
<br />
I believe the problem with the discrepancy I am seeing with the Client Table is a firmware glitch. I have been on that screen today and will see a list of 25 connected devices, some with static IP and some going through DHCP. But I can navigate away from that screen and then back again and see zero entries listed. I can't think of anything else that would cause that issue because there would be no network change during that time.<br />
<br />
Fred - I have updated the Client Lease Time to 480 minutes. This has also seemed to help get rid of the straggling IP addresses that were continuing to show up in as DHCP even though I had assigned a static IP address. There is a chance some of those devices were inactive when I added them to the static IP table so there was no release and renew that took place.<br />
<br />
Ian - Thanks for the comments. I believe a big part of my problem was linked to the comment you made, as I indicated above. I was allowing the NIC of most devices to use DHCP even though I had entered the MAC for that NIC as a static IP in the router. I did not initially think this would cause a problem, but after researching this more based on John's comment I think that was a big part of my problem. I have also taken your advice and used only the non-assigned IP addresses, 10.10.1.10-99, as my static IP addresses. Before I had primarily used the IP addresses in this range, but I did have a few of my devices assigned a static IP from the DHCP pool of 10.10.1.100-249.
</div>


<div>
Thank you for a comprehensive update and I was happy to help.
</div>


<div>
Hi Gacto,<br />
<br />
Thanks...pleasure helping you out...thanks all for the valuable contribution
</div>


<div>
Thanks! &nbsp;<br />

<blockquote>
There is a chance some of those devices were inactive when I added them to the static IP table so there was no release and renew that took place
</blockquote>
. &nbsp;All this is likely getting into the specifics of a particular router design. &nbsp;Some may handle their lists one way and some rather differently. &nbsp;<br />
<br />
There is no &quot;release and renew&quot; process that I know of unless you do it manually from the client: i.e.:<br />
ipconfig /release<br />
ipconfig /renew<br />
The /release tells the server to cancel the lease and it's supposed to free up the IP address. &nbsp;So, I would expect that a computer would drop off the list after a release (and some suitable wait time).<br />
<br />
Otherwise, the server will keep a list of active leases whether the clients are there or not.<br />
<br />
In the case of reserved IP addresses by MAC address, well that's a bit of a mixed bag I should think.<br />
In this case there is no &quot;lease&quot; as such because these are permanent assignments.<br />
My notion of how it works would be:<br />
- a client comes on line.<br />
- the server checks its MAC address against the reserved list and assigns the indicated IP address if there's a match. &nbsp;<br />
- if there's not a match then the server issues an IP address out of the DHCP pool with a lease.<br />
Thereafter, if a client goes off line:<br />
- leases remain until they expire. &nbsp;So a dynamic client can come and go and get the same IP address upon returning as long as the lease remains.<br />
- static (DHCP reserved) assignments remain indefinitely. &nbsp;So a &quot;static&quot; reserved client can come and go and get the same IP address upon returning .. period.<br />
Given all that, one can imagine lists:<br />
- list of active leases.<br />
- list of static reserved assignments (this one is obvious because you enter it manually - and, so, why display it separately?)<br />
- list of active clients (this is equivalent to an arp table relating MAC addresses to IP addresses).<br />
The arp table refreshes in some period of time. &nbsp;I've seen some devices that are quick about it and others that are slow. &nbsp;I've seen some that have to be forced to flush in order to get new information into them in a reasonable period of time. &nbsp; A good example is introducing a replacement device that uses the same static IP address as the device it's replacing. &nbsp;In that case the arp table will have a MAC/IPADDRESS mismatch until the new MAC address is entered.<br />
Anyway, the arp table will have all of the active devices no matter how they got their IP addresses.<br />
I hope that helps!
</div>


<div>
<div class="content wysiwyg-content">
I have a Cisco RV042G setup as a DHCP Server and have added most of my hardware devices with static IP addresses. But even after adding in all of the devices with a static IP, I am still seeing odd behavior from the router. Here are the main issues I am seeing:<br />
<br />
1. Some devices that are setup with a static IP address still show up when I click on &quot;Show unknown MAC addresses.&quot; For example, I have an AppleTV setup with a static IP, the MAC address is entered and the AppleTV displays the correct IP address as I have entered in the static IP table. But still when I view a list of unknown MAC addresses, the AppleTV is listed. How can the device show up in both tables? If I have assigned a static IP to the MAC address, that should, by default, preclude that IP address from being unknown.<br />
<br />
2. DHCP Status never shows the right number of connected devices and almost never shows any devices in the client table. Occasionally there will be one or two devices listed, but I have 20-30 listed in my static IP table. I cannot figure out why the client table would not show all connected devices.<br />
<br />
Can someone help me with these two questions? I haven't determined that these issues are causing any performance problems with my network, but I am quite concerned about the inconsistency in the DHCP information.<br />
<br />
My hardware is RV042G v01 running firmware v4.2.3.07 (Oct 8 2015 15:29:55).
</div>
</div>


I have a Cisco RV042G setup as a DHCP Server and have added most of my hardware devices with static IP addresses. But even after adding in all of the devices with a static IP, I am still seeing odd behavior from the router. Here are the main issues I am seeing:

1. Some devices that are setup with a static IP address still show up when I click on "Show unknown MAC addresses." For example, I have an AppleTV setup with a static IP, the MAC address is entered and the AppleTV displays the correct IP address as I have entered in the static IP table. But still when I view a list of unknown MAC addresses, the AppleTV is listed. How can the device show up in both tables? If I have assigned a static IP to the MAC address, that should, by default, preclude that IP address from being unknown.

2. DHCP Status never shows the right number of connected devices and almost never shows any devices in the client table. Occasionally there will be one or two devices listed, but I have 20-30 listed in my static IP table. I cannot figure out why the client table would not show all connected devices.

Can someone help me with these two questions? I haven't determined that these issues are causing any performance problems with my network, but I am quite concerned about the inconsistency in the DHCP information.

My hardware is RV042G v01 running firmware v4.2.3.07 (Oct 8 2015 15:29:55).

Cisco RV042 DHCP Problem

Cisco PIX is a dedicated hardware firewall appliance; the Cisco Adaptive Security Appliance (ASA) is a firewall and anti-malware security appliance that provides unified threat management and protection the PIX does not. Other Cisco devices and systems include routers, switches, storage networking, wireless and the software and hardware for PIX Firewall Manager (PFM), PIX Device Manager (PDM) and Adaptive Security Device Manager (ASDM).

Cisco

A router is a networking device that forwards data packets between computer networks. Routers perform the "traffic directing" functions on the Internet. The most familiar type of routers are home and small office cable or DSL routers that simply pass data, such as web pages, email, IM, and videos between computers and the Internet. More sophisticated routers, such as enterprise routers, connect large business or ISP networks up to the powerful core routers that forward data at high speed along the optical fiber lines of the Internet backbone. Though routers are typically dedicated hardware devices, use of software-based routers has grown increasingly common.

Routers

The Dynamic Host Configuration Protocol (DHCP) is an auto configuration protocol used on IP networks and an extension of the Bootstrap Protocol. DHCP allows for computers to be configured automatically to communicate with each other over an IP network without the need for manual setup by a network administrator. The implementation of DHCP relies on a DHCP server to hand out network configuration information to DHCP-capable clients that request an IP address (and other information required or useful in communicating with other devices on an IP network). In addition to an IP address, common configuration information served over DHCP includes a default gateway, subnet mask and DNS sever(s).