DHCP: force router to assign predefined infinite DHCP address

Does anyone know if its possible to force a router only to assign an infinite DHCP address when a client connect to the network?
In the configuration (2911 router) there is an DHCP server configured which assigns specific IP addresses to certain mac addresses (in this example to Client1 with mac address 00aa.00bb.00cc.ab). Due to security reasons I want to avoid that a user of a device can manually set a different ip address on his device and still be able to use/connect to the router (so far this is possible).
DHCP config is:
ip dhcp pool data
network 192.168.2.0 255.255.255.0
default-router 192.168.2.1
dns-server 10.10.10.1
ip dhcp pool Client1
host 192.168.2.10 255.255.255.0
client-identifier 00aa.00bb.00cc.ab
dns-server 10.10.10.1
default-router 192.168.2.1
Thanks, Frank

you can use IP source guard feature along with DHCP snooping to mitigate such a security threat.
Ip source guard uses DHCP snooping database to test that if incoming packet's source ip is assigned by dhcp server or not, in case of illegal source ip address, the packet will be dropped.
HTH

Similar Messages

SG500 - DHCP server does not assign predefined static IP addresses to hosts

hi guys
I upgraded my SG500 switch firmware to 1.3.0.59, since there is a new functionality DHCP server v.4
well I must say I came accross the issue I cannot solve. DHCP server assign dynamic address - no hassles.
troubles start with static IP hosts.
I defined a couple of hosts with static address within the correct subnet. I tried with hardware address and client identifiers. no luck. my switch does not assign the IP address I assigned to the suitable mac address. to define it I use both CLI & Web.
no of them works. any idea ?
below the cut from my config:
ip dhcp pool host HP-Ellite
address 10.10.11.7 255.255.255.0 client-identifier 01:d8:d3:85:cf:09:72
client-name HP-Ellite
default-router 10.10.11.1
exit
ip dhcp pool host VAIO-Z
address 10.10.14.108 255.255.255.0 hardware-address 54:53:ed:1c:a1:46
default-router 10.10.14.1
exit

Tom, thnkas for a quick reply...
look, usually it is pretty easy to manage an issue with so precise instructions. but this particular time it is not.
as I understood the "dhcp option 61" is nothing more than "00" which go before pure hardware address.
so, coming back to my example from the first post
with this configuration, my switch assigns 169.254.110.130 255.255.0.0 address
ip dhcp pool host HP-Ellite
address 10.10.11.112 255.255.255.0 client-identifier 01:d8:d3:85:cf:09:72
client-name HP-Ellite
default-router 10.10.11.1
exit
with that configuration, my switch assigns 10.10.11.11 255.255.255.0 address
ip dhcp pool host HP-Ellite
address 10.10.11.112 255.255.255.0 client-identifier 00:d8:d3:85:cf:09:72
client-name HP-Ellite
default-router 10.10.11.1
exit
otherwords "00" does not work as explained (unless I misunderstood the meaing of dhcp option 61). my switch assigns first available dynamic IP address. atlhough the arp table is cleared, dynamic address table is cleared as well. swtich is rebooted, host is rebooted
once I change hardware address prefix to "01", my host asign itself 169.xxx.xxx.xxx adress.

Router is assigning the same IP address

i'm trying to hook up my ps3 and iMac to my wireless router and its assigning both the same IP address so that when I use the internet on one it disconnects the internet on the other. I have no idea how to fix this but I figure it has to be something with my router thanks in advance

It is not possible that router is providing both the devices same Ip address ...... if you had laready provided any Ip addres to either PS3 or I-Mac in that case there would be an Ip address conflict error in your network .....
You can try one thing .... change the Ip address from Maunal to Automatic ....
Also open the routers set up page usin http://192.168.1.1 on browser address bar .....
You will see username & password screen ..... leave username blank & in password use admin.....
Click on wireless ...change the network name to any non-linksys name ........channel - 1 or 11 ..... click save settings .....
Click wireless security ..... use either WEP or WPA security .... have a note of security key .....
Click save settings .....
Check on PS3 & I-Mac if both are connecting to same network at the same time ........

Problem with Linksys Router Model WRT110 Not Assigning IPs With DHCP?

Hello,
I recently purchased this router (WRT110) to take the place of my old Belkin that was continually dropping connections (which was a real pain when trying to download stuff off the Internet).
However, I cannot get this router to assign IPs to wired or wireless computers. I spent around 2 hours talking to Linksys support technicians (two total) before they finally told me the router was defective.
So, I went back to the store and got an exchange. But, it's the same story with this router, the connections can't get past the "acquiring network address" stage in the connection process.
I would like to think that this has more to do with my ISP than the router, but if I set up a static IP on the wired computer I can connect to the Internet and the router through its default gateway. Setting up a static IP on the wireless computer doesn't seem to work, however. If the ISP was a problem, wouldn't the router not detect the Internet connection at all?
DHCP is definitely enabled on the router also.
My ISP is a small town owned company. I have a wireless broadband connection, which works similarly to satellite, only the connection is broadcast via a tower and is received with an outside antenna.
I still need to contact them about this, but I figured it could hurt to ask here and see some of your suggestions.
Thank you!
~RJG

UPDATE: I contacted my ISP today and the technician I spoke with said he didn't know of any problems any routers would have with their wireless broadband. I tend to agree with him, as I've configured two routers previously using my connection and I've never had any difficulty until now. He suggested changing the ethernet cable and releasing/renewing my IP address, both of which I did but I continued to have the same issues.
But, after doing some more research I found some settings that actually allowed my wireless computer to connect. There was a post in these forums referring to modifying the MTU, changing it from Auto to Manual and changing the value to 1458 actually seemed to work, as well as strengthening the connection by changing the beacon interval. Anyway, I can connect wirelessly now.
Also, I connected my Linux computer (Ubuntu 8.04 Hardy Heron) to the router and was able to connect instantly, no problems whatsoever. So, out of my three computers, two are connecting, but my wired Windows computer is still having issues. However, if I set a static IP for that computer, I can connect fine.
I'm thinking maybe there is something wrong with the NIC card in that computer, but how would one test something like that?
It doesn't make sense to me, I would really appreciate any input. Thank you!

DHCP server does not assign IP addresses SG500 firmware 1.3.5

good day collegues
has any of you come across the following issue:
my switch (after upgrading to the newest firmware 1.3.5) does not assign IP addresses to some of the hosts.
after a couple of hours I managed (do not even how) to force my switch to assign IP addresses only to some of the hosts.
still some of them cannot get the IP address and remain with "funny" IP address like i.e. 169.254.100.100
additional info
1. if I boot my switch with the previous version of firmware (1.3.0.6) everything is OK. all my hosts get correct IP addresess
2. the hosts which do not get IP address were perviously entered in stat host table - now removed, ARP cleared, etc, everything many many times rebooted.
I ran out of ideas, could you pleae give me some hints ?
the config below:
config-file-header
SG500
v1.3.5.58 / R750_NIK_1_35_647_358
CLI v1.0
set system mode router queues-mode 4
file SSD indicator encrypted
ssd-control-start
ssd config
ssd file passphrase control unrestricted
no ssd file integrity control
ssd-control-end zzz
no spanning-tree
vlan database
vlan 11,13-14
exit
voice vlan oui-table add 0001e3 Siemens_AG_phone________
voice vlan oui-table add 00036b Cisco_phone_____________
voice vlan oui-table add 00096e Avaya___________________
voice vlan oui-table add 000fe2 H3C_Aolynk______________
voice vlan oui-table add 0060b9 Philips_and_NEC_AG_phone
voice vlan oui-table add 00d01e Pingtel_phone___________
voice vlan oui-table add 00e075 Polycom/Veritel_phone___
voice vlan oui-table add 00e0bb 3Com_phone______________
no ip dhcp snooping verify
ip dhcp snooping information option allowed-untrusted
ip dhcp snooping vlan 11
ip dhcp snooping vlan 13
ip dhcp snooping vlan 14
ip arp inspection logging interval infinite
green-ethernet energy-detect
no eee enable
arp timeout 1
ip dhcp server
ip dhcp pool host q409
address 10.10.11.2 255.255.255.0 client-identifier 01:00:08:9b:ac:8f:92
default-router 10.10.11.254
dns-server 10.10.10.1
exit
ip dhcp pool host PCH-100
address 10.10.11.10 255.255.255.0 client-identifier 01:00:06:dc:41:ef:ef
default-router 10.10.11.254
dns-server 10.10.10.1
exit
ip dhcp pool host q209
address 10.10.13.3 255.255.255.0 client-identifier 01:00:08:9b:ac:72:ba
client-name q209
default-router 10.10.13.254
dns-server 8.8.8.8
exit
exit
ip dhcp pool network HOME
address low 10.10.11.1 high 10.10.11.254 255.255.255.0
lease infinite
default-router 10.10.11.254
dns-server 10.10.10.1
exit
ip dhcp pool network GUESTS
address low 10.10.14.1 high 10.10.14.254 255.255.255.0
lease infinite
netbios-node-type b-node
default-router 10.10.14.254
dns-server 10.10.10.1 62.233.233.233
exit
ip dhcp relay address 10.10.10.1
ip dhcp relay address 10.10.11.254
ip dhcp relay address 10.10.13.254
ip dhcp relay address 10.10.14.254
no boot host auto-config
no qos
qos advanced-mode trust dscp
qos wrr-queue wrtd
exit
hostname SG500
line telnet
exec-timeout 0
exit
logging buffered debugging
no logging file
aaa authentication login Telnet local
aaa authentication enable Telnet enable
aaa authentication dot1x default none
line telnet
login authentication Telnet
enable authentication Telnet
password 999 encrypted
exit
no passwords complexity enable
passwords aging 0
username 999 password encrypted 999 privilege 15
ip http timeout-policy 0 http-only
clock timezone " " 1
clock summer-time web recurring eu
clock source sntp
clock source browser
sntp unicast client enable
clock dhcp timezone
ip domain name 999
ip name-server 10.10.10.1 62.233.233.233 8.8.8.8
ip host 999 10.10.13.3
ip telnet server
no service mirror-configuration
no security-suite deny syn-fin
security-suite syn protection mode disabled
interface vlan 1
ip address 10.10.10.254 255.255.255.0
no ip address dhcp
interface vlan 11
name HOME
ip address 10.10.11.254 255.255.255.0
ip dhcp relay enable
interface vlan 13
name DMZ
ip address 10.10.13.254 255.255.255.0
ip dhcp relay enable
interface vlan 14
name GUESTS
ip address 10.10.14.254 255.255.255.0
ip dhcp relay enable
interface gigabitethernet1/10
description "(99) QNAP 409"
switchport trunk native vlan 11
exit
macro auto disabled
macro auto processing type host enabled
macro auto processing type ip_phone disabled
macro auto processing type ip_phone_desktop disabled
macro auto processing type router enabled
mac address-table aging-time 10
ip default-gateway 10.10.10.1
snmp-server set 999 permit

Hi Andbor, please make a backup config of your file, factory reset the switch.
After this, manually configure a DHCP scope without any other configuration.
Just something simple like this
ip dhcp pool network GUESTS
address low 10.10.14.1 high 10.10.14.254 255.255.255.0
lease infinite
netbios-node-type b-node
default-router 10.10.14.254
dns-server 10.10.10.1 62.233.233.233
Verify your machine receive IP address with no other configuration.
In some ways, I'm afraid some of your connections black listed due to the arp inspection.
-Tom
Please mark answered for helpful posts

Routing and Remote Access VPN DHCP error

I have a strange problem.
I have a client that is using Server 2012 Standard.
On this server they have Routing and Remote Access configured for VPN client access. Their users that are working outside the office connect to the VPN to access the internal network.
The VPN works fine for the most part. Recently however, it has started having issues.
Periodically (about once every 8 days) I will hear from them that they cannot connect and that they get error 720. I will check the server and the server will have the following errors in the event log:
Warning: No IP address is available to hand out to the dial-in client.
If you check DHCP the server is running fine and will hand out local addresses but it will not hand out addresses to VPN clients. Also the addresses that it HAS previously handed out to VPN clients will not show in the address leases.
The solution strangly enough is to disconnect and reconnect a the VPN client connection that the server has connecting it to a offsite server that it does a SQL sync with.
Any ideas as to what might be causing this? If need be I can post more detailed logs but I am not sure what logs even to post or what data to collect.
Any help is greatly appreciated.

I am experiencing the same issue on a Windows 2008R2 SP1 RAS server. The above statement About increasing the lease time on DHCP does not resolve the problem.
I am also Searching for a Solutions to this issue.
Up to now I have done the Following :
1. Increased the scope/ cleared IP's in DHCP.
2. Ensure that the DHCP server is accessable.
3. Created a Manual Scope on RRAS configurations settings (then clients can connect but cannot access resources on the network). Changing Back to DHCP, you recieve the same 720 Error.
4. Stop and started the DHCP services on the DHCP Server.
5. Stop and Started RRAS Services on RRAS server.
The Only Indication is, that DHCP for some reason does not lease out Addresses to the RRAS server..

DHCP client fails to get an valid IP address from DHCP server. windows 8.1

I have a win 8.1 Pro 64 bit pc in my office .I'm trying to connect it to my wireless cisco router with either wireless or hardwired connection but I get an error in the event viewer with discription DHCP error 1007. and Ip address showing
169.254.93.17 but our dhcp range is 192.168.1.x
Log Name: Microsoft-Windows-Dhcp-
Source: Microsoft-Windows-Dhcp-Client
Date: 23/Jun/2014 12:03:21 PM
Event ID: 1001
Task Category: Address Configuration State Event
Level: Error
Keywords: (1)
User: LOCAL SERVICE
Computer: sanddeplap.vts.com
Description:
Your computer was not assigned an address from the network (by the DHCP Server) for the Network Card with network address 0xF4B7E22D8721. The following error occurred: 0x79. Your computer will continue to try and obtain an address on its
own from the network address (DHCP) server.
Event Xml:
<Event xmlns="http://schemas.">
<System>
<Provider Name="Microsoft-Windows-Dhcp-
<EventID>1001</EventID>
<Version>0</Version>
<Level>2</Level>
<Task>3</Task>
<Opcode>75</Opcode>
<Keywords>0x4000000000000001</
<TimeCreated SystemTime="2014-06-23T08:03:
<EventRecordID>363</
<Correlation />
<Execution ProcessID="988" ThreadID="7932" />
<Channel>Microsoft-Windows-
<Computer>sanddeplap.vts.com</
<Security UserID="S-1-5-19" />
</System>
<EventData>
<Data Name="HWLength">6</Data>
<Data Name="HWAddress">F4B7E22D8721<
<Data Name="StatusCode">121</Data>
</EventData>
</Event>
I tried to track issue with microsoft network monitor I'm attaching the capture file also please help me to sort out this issue
capture report https://onedrive.live.com/redir?resid=AFE3D0245A92F6F8%21183

The issue is that your machine is not being assigned an IP address / was unable to reach the DHCP server to receive one. The 169.254.x.x IP your machine is showing isn't assigned from DHCP, it's assigned by the local machine and is referred to as an APIPA
address.
So something is preventing your machine from reaching your DHCP server, which could one of a number of things. In the first instance I'd suggest having a look at
http://epan36.blogspot.co.uk/2012/09/eventid-1001-dhcp-your-computer-was-not.html which lists several of things that could cause this error and things you can try in order to resolve it.
If none of those work, can you confirm whether you have any other machines connecting via the same method on the network, which might indicate whether this is an issue at the machine end or somewhere between the machine and DHCP server?

DHCP to send different Gateways based on MAC-Addresses

Hello,
I would like to use the built-in DHCP server to send out different Gateways based on the clients' MAC-Addresses.
I have already managed to assign "static" IP-Adresses using the DHCP server to specific MAC-Adresses.
Is this possible or do I need additional software ?
thanks for your help

The basic IP networking construct here is the IP subnet (and the subnet mask); that's how you set up groups of related network hosts in an IP network. Hosts within a subnet tend to have the same DNS and gateway router and related pieces configured, and one DHCP server and such. (That's not strictly necessary, but...)
Launch Server Admin, select the DHCP service, set up subnets via the DHCP service by subnet mask, and establish DNS and default router settings there for each of the subnets.
Then set up static maps for the MAC address(es) associated with the hosts, and drop the static IP addresses into the particular subnet you want the host associated with.
You will want to leave room in the subnet for both the DHCP allocations (if any) and for the static hosts mapped into the subnet via MAC address.
There well may be a better way here, but this will get you where you want. (And the Network Services Administration manual - which you'll need to read - does seem a bit confusing around this particular sequence.)
nb: I don't have a "scratch" Leopard Server configuration handy to test and confirm this sequence.
nb: Xserve boxes require a little extra thought, given each Xserve box tends to have four MAC addresses.

Trying to set up Directv GenieGO using Airport Extreme. Getting error message: DHCP range entered conflicts with the WAN IP Address of your base station. How do I resolve the conflict.

Trying to configure an Airport Extreme manually. After I enter the IP Address of the GenieGo along with the rest of information required I am getting the following error message when I click update:
DHCP range entered conflicts with the WAN IP address of your base station.
How do I resolve the conflict?

You cannot use the same range on LAN and WAN if you are routing.. it must be different.. and you should not be routing at all.
The AE should be in bridge mode. NO DHCP settings at all.

*DHCP Server: %DHCP-3-ADDR_NOTIN_POOL: pools.c:158 Error: Ip Address 0.0.0.0 is not in pool (10.0.1.4- 10.0.1.254)

Anyone have knowledge about this error:
*DHCP Server: Jul 19 12:58:19.565: %DHCP-3-ADDR_NOTIN_POOL: pools.c:158 Error: Ip Address 0.0.0.0 is not in pool (10.0.1.4-> 10.0.1.254)
I am using DHCP Server of 5508
Software Version
7.0.98.0
and the attached configuration.
Thanks

Hi,
Here is the SHOW STOPPER bug that we have on the version that you are running relating to the internal DHCP pool..
http://tools.cisco.com/Support/BugToolKit/search/getBugDetails.do?method=fetchBugDetails&bugId=CSCth68708
Please upgrde the software to 7.0.116 and this will resolve the issue.. lemme know if this answered ur qestion
Please dont forget to rate the useful posts!!
Regards
Surendra

HP PSC 2510 on BEFW11S4: assigning / reserving an IP address

I use an HP PSC 2510 printer / scanner copier on my home network, with a wired connection to my BEFW11S4 ver. 2 (firmware 1.45.10). About two months ago, I started experiencing intermittent connectivity problems (for which I asked assistance in a separate post). I also reconfigured my printer around that time, to connect via IP address (192.168.1.100) rather than host name (NPID11408), so I thought I'd mention that here.
The problem I initially intended to write about is that whenever I reset the router, I turn off all the other computers (or at least their connections), and reset the printer before turning the router back on again, so that the printer always comes up with the first assigned IP address (192.168.1.100). Is there a way to "reserve" this local IP address so that it always (and only) gets assigned to the printer? Since someone currently needs to reset the router on a nearly weekly basis, the extra work of turning everything else off and on again is a real hassle.
I say "initially" above, because in writing this, I am wondering whether my reconfiguration of the printer is a factor in the intermittent connectivity problems with the BEFW11S4 I wrote about a little while ago. In case they are related, and anyone else reading this has any insights, here's a listing of the HP Network Configuration page:
Network Connection Type: Wired
URL: http://192.168.1.100
Hardware Address: 00306ED11408
Firmware Version: B.25.38-RL6206xNS
Host Name: NPID11408
IP Address: 192.168.1.100
Subnet Mask: 255.255.255.0
Default Gateway: 192.168.1.1
Config Source: DHCP
DNS Server: [omitted]
mDNS: psc 2500 series (00306ED114008)
Admin Password: [omitted]
Link Config: 100TX-Full
On Windows XP (for my Dell, Toshiba and Sony computers), the printer port is configured to use the IP address. When I first got the printer, and installed the software on the Dell and Sony, I was able to use the Host Name, but for some reason, I couldn't get the Toshiba to see the printer via the hostname, but all computers could see the printer via the IP address. My Mac can also see the printer via the IP address.
I would welcome any suggestions (or questions) from anyone who can help me configure the router to assign 192.168.1.100 to the printer (or at least reserve it for the printer). Thanks!
Joe.

This will have each device on your network operating from a fixed IP address corresponding to the one the DHCP server had assigned. Now that address will not change. Note, however, that if a device is removed from the network and some new device is connected to which the DHCP server assigns the same address, then you cannot reconnect the other device until the new one is removed or you can end up with two devices trying to use the same IP address which will generate a system error.
I did manually assign specific and unique IP addresses to each computer. Everything worked fine. However, once I had the computers turned on in a different sequence and there was an IP conflict. I am not sure why? I had to manually change the IP address. Is the router's DHCP server trying to assign IP addresses to the computers?
I notice now that in my router's control panel, there are no IP addresses in the "LAN > DHCP Client List"— No leases. Before I manually assigned addresses, there was a list of IP addresses. Would it not make sense for the DHCP Client List to still show what IP address are currently in use?

How do I assign a static IP address?

I bought mSecure from mSeven Software for my iPhone. Had no problem assigning a static IP address to my old PC laptop, but now I've happily switched to Macbook Pro and I can't figure out how to get it done. Need this static IP address to sync my iPhone data to the Macbook Pro. Found something that said I needed to go to "server admin" but I can't figure that out either. I do see how to find my IP address (in system preferences), but I'm not sure how to assign a static address. I'm not the most computer literate person in the world, but I'm fairly teachable - can somebody walk me through this step by step (including what buttons to push to get where you guide me)? Much obliged.

Oh great, forum notifications have grown funky again.
As I understand your question, each client (whether it's a router or not) can be configured to receive its IP address via DHCP, or not. In the latter case you specify its IP address manually in the client. I can't think of a TCP/IP client that does not have this ability.
There is no way to use AirPort Utility to assign specified IP addresses to clients, though you can "reserve" a block of addresses that it will not assign via DHCP.
You can assign an IP address to a client using a directed IP packet, using Terminal (must be run as superuser):
arp -s <desired IP address> <client MAC address>
... but this does not create any entries in the AirPort's MAC address table. Is that what you want to do?

Is it possible to assign fixed internal IP address for Azure VM ?

I setup win2008R2 Application server on Azure VM and setup Azure VPN for local address 10.0.0.0/24 and VNET? for 10.0.1.0/24 and default gateway 10.0.1.0/25 though I do not get exact meaning of this network settings.
By default VM OS IP setting, it get IP address through DHCP.
1
If I make Azure VPN, it is assigned the specified range automatically ? ( in this case, 10.0.1.0/24 ).
2
If I do not use Azure VPN, which range of address is assigned as internal IP to Azure VM through DHCP ?
3
If I set fixed IP address in that VM from OS setting , it will survive and IP address is not assigned by DHCP both using Azure VPN case and not using Azure VPN case after OS reboot from OS and from Azure
Portal ?

For general information:
Gateway - Usually this is your router. When you talk about your gateway, generally you are talking about the ip address your router uses.
NAT - Network Address Translation. When your router is using nat, it is taking data from one Public IP address, and breaking that data into multiple private ip addresses. Data is sent to your network on a public ip address, from the internet. Using nat your router then directs that data, to multiple internal private ip addresses. Nat basically breaks one ip into many.
IP Addresses :
1-External (Public) IP Address - Every computer/server that has a public ip address is directly connected to the internet. Usually DLS/cable routers are assigned a public ip address by the ISP they are connecting to.
(The Dynamic/Static relates to how an ip address is assigned.)
a) Static : Your ISP assigns an IP number and cannot be change by user (client).
To do : If you want to change it by any reason, call your ISP and ask them to change your IP number.
b) Dynamic : Your ISP assigns an IP number and you can change it. This means that every time your DSL modem is rebooted, your ISP assigns a new IP number for it.
To do : Turn your modem off/on. (Wait for 15 seconds between off/on.)
2-Internal (Local) IP Address - If you are using NAT, every computer on your network has one of these ip addresses. These IP addresses are provided by your router. Your entire network can see this ip address. Computers on the outside of your network can not, because your router "hides" private ip addresses.
Hope this helps you.
Fatih
iMac G5 20"-2Ghz 1GB RAM / PB G4 1.67-1GB RAM/PB G4 400-768 RAM/iMac DV G3 400 Mac OS X (10.4.4) Ext.FW 1204030 - iSight

Router MI424WR - Device Names to MAC Addresses Question

I have Verizon FiOS with an ActionTec MI424WR Router. I have many devices connected to it on our home network: ipods, ipads, nook, kindles, laptop, roku, and a desktop.
For each device, I found its MAC address. Then I logged into the router and went to "My Network." There, I renamed each device (for example, from "android-alsdfjl3kljasdf" to "JonKindle" and "new-host-4" to "MaryIpad"). That way, I'll be able to go to the parental controls rules screen and assign each device to rules as I like.
Problem:
The names keep changing back to "android-alsdfjl3kljasdf" and "new-host-4". Not only that, but somehow, the MAC addresses keep changing. Is there a way to keep that from happening?
I thought MAC addresses were assigned to a piece of hardward and didn't change. Can someone please enlighten me?
Thanks,
smy

smy wrote:
Problem:
The names keep changing back to "android-alsdfjl3kljasdf" and "new-host-4". Not only that, but somehow, the MAC addresses keep changing. Is there a way to keep that from happening?
I thought MAC addresses were assigned to a piece of hardward and didn't change. Can someone please enlighten me?
The trick to make the [name, MAC address] permanent is to assign a static DHCP lease to each device. Otherwise, when the lease expires and the device is no longer active, the router forgets everything about it.
As for changing MAC address, you are correct, they shouldn't change.
If you have multiple "Android-xxx" devices they may be coming up in a different order, thus creating the appearance of changing addresses. Make a list of every active MAC address and attempt to correlate it to your devices. The next time you think one changed, look and see if it's on your list.
MAC addresses can be changed by the user on some devices, however this is typically only done to "play" with a network or circumvent security features.
Good Luck.
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I have an Airport Extreme as my router and am using time capsule to extend the network in my new house. My ISP is only providing me 4-5 ip addresses and wants me to set up my router to issue out new ip addresses for all my devices.How do I fix this?Help

I have an Airport Extreme as my router and am using time capsule to extend the network in my new house. My ISP is only providing me 4-5 ip addresses and wants me to set up my router to issue out new ip addresses for all my devices.How do I fix this?Help.
They said I need to change my settings to NAT settings. I haven't been able to figure out or find anything. I have also spoken to Apple Support on the phone for hours without being able to figure out how to do this ( i don't think he knew much either lol.) Please help me because I've got about 15-20 devices in my house that require to be connected to the internet and this is just making things ridiculously slow and painful for me.
Thanks!

It is on DHCP & NAT under router mode yet my isp is still the one issuing ip addresses to my devices instead of the router issuing them

DHCP: force router to assign predefined infinite DHCP address

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