Strange DHCP client identifier

I am troubleshooting DHCP between server and client (both Cisco IOS). I have discovered, that server sees client under completely nosensical client identification:
R1#sh ip dhcp binding
Bindings from all pools not associated with VRF:
IP address Client-ID/ Lease expiration Type
Hardware address/
User name
10.0.6.3 0063.6973.636f.2d30. Apr 01 2001 10:40 PM Automatic
3062.302e.6332.3838.
2e31.3637.312d.4661.
30
Yes, the client id server sees is "3062.302e.6332.3838.2e31.3637.312d.4661.30" instead of little more conventional "00b0.c288.1671". What's up here? This thing makes manual binding impossible, as that long number is not accepted in "client-identifier" on server.
Edit: No, I wasn't cut'n'pasting properly, that long client-id can be entered into pool configuration. So that solves the problem, and the only think that remains unanswered for me is what were Cisco thinking, when they decided that client-id is going to be this kind of crazy stuff instead of plain MAC.

Some Cisco networking devices use a DHCP client identifier format that is different from the format used by networking devices running Cisco IOS release 12.4(1) or newer.
Ref link: http://www.cisco.com/en/US/partner/products/ps6441/products_configuration_guide_chapter09186a008054afa2.html
But, you should be able to bind that full (long) address to the the client IP in your DHCP pool configuration and I've done that before. If you are having problems refer to this link:
http://www.cisco.com/en/US/partner/products/ps6350/products_configuration_guide_chapter09186a008054addc.html#wp1204466
HTH
Sundar

Similar Messages

How to configure dhcp client identifier

Hi Everybody,
The DHCP client ID is an id that is unique for DHCP clients at least in the same subnet. Usually the client uses MAC-address as Client-Identifier in the DHCPDISCOVER message. The Client-Identifier may be different other than MAC-Address, For example a FQDN name, as per the RFC 2132 Ref, (code 61).+_
Usaually, we use the following to bind the ip address based on MAC-address
pntadm -r SUNWfiles -p /var/dhcp -A 10.42.32.86 -i '0:3:ba:a5:a9:93' -a 10.42.32.80
At server side, I am using the following for specifying the FQDN name.
pntadm -r SUNWfiles -p /var/dhcp -A 10.42.32.86 -i 'one.atr.com' -a 10.42.32.80
and at client side, I am inserting the following entry in the /etc/default/dhcpagent file
CLIENT_ID='one.atr.com'
But this is not working. What I am doing wrong.
+1. At the server side, then how to assign the ip addresses to the clients , if the Client-Identifier is FQDN name in the DHCPDISCOVER message other than MAC-Address.+
+2. How to configure the client-identifier as FQDN name at client side.+
Please help me,
Thanks Inadvance,
Mummaneni.

Sandman,
Here is an example of a router acting as a DHCP server. Please remember that you have to exclude IP addresses that you don't want to lease out.
ip dhcp pool example
import all
network 192.168.1.0 255.255.255.0
dns-server 1.2.3.4
default-router 192.168.1.1
ip dhcp excluded-address 192.168.1.1 192.168.1.149
ip dhcp excluded-address 192.168.1.200 192.168.1.254
HTH,
Mark

Removing DHCP Client identifier Option 61

Long story short after wasting a LOT of time i figured out that my ISP won't offer IP if there's Option 61 Client identifier included in my DHCP Discover. (i tried throwing my MAC in there but it didn't work) is there any way to remove it? Or filter it out?

Welcome to the forums. Just so you know, this is a peer-to-peer support forum. Verizon does not answer questions here.
Sometimes the Verizon moderators escalate issues to the support team, which is an extension of the Verizon folk you can reach by using the "contact us" link at the bottom of these pages. If that happens to your issue, be sure to follow the instructions the moderators post.
Unfortunately, I do not know of any methods to reach Verizon's network engineers. They keep them very well separated from customers. Verizon keeps their residential customer contact very focused on the public support channels.
It's possible some of the other users here may know details about your question, but I'm not one of them.
Good Luck.
If a forum member gives an answer you like, give them the Kudos they deserve. If a member gives you the answer to your question, mark the answer as Accepted Solution so others can see the solution to the problem.

CNR DHCP Client-class

We are using CNR with multiple scopes to provide ip addressing for both computers and IPTV set top boxes. The STB's require boot params in dhcp option-131 and option-240. I have set up a client-class-policy that contains the two options and when I set up a client with an exact mac address, then the information is provided correctly.
The problem is we have hundreds of STB's. How do I get CNR to generalize the client mac address to just the first 3 bytes?
I have tried creating a client with 00:00:00 for the last three bytes and then altering the dhcp-client-identifier to match, but it doesn't work.
The docs state that you can create a client-lookup-id expression but shows no examples.
Thanks.

Reread the docs closer and found that the environment parameter 'default-client-class-name' is only visible in the pre-client-lookup extension. So in the post-packet-decode extension I check the request parameter 'dhcp-class-identifier' and then set a environment parameter stb-type to a class name.
In the pre-client-lookup I check to see if the stb-type is in the environment dictionary. If it is then I set 'default-client-class-name' to that value. This forces the DHCP to use the client-class of the same name as the default for this DHCP request. Since I set the option 131 in the appropriate client-class-policy then it all works. Don't even need a client set up at all.
Thanks for the response on expressions. Looks like I may have been able to do it that way too.

DHCP client to send option 60

Hi,
I am running Yosemite 10.10.2 and I would like to enrich DHCP discover message sent by the mac os client with option 60 vendor-class-identifier.
After various reading on the support web site, I tried to update this file: /System/Library/SystemConfiguration/IPConfiguration.bundle/Contents/Info.plist like this :
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
        <key>BuildMachineOSBuild</key>
        <string>14C92</string>
        <key>CFBundleDevelopmentRegion</key>
        <string>English</string>
        <key>CFBundleIdentifier</key>
        <string>com.apple.SystemConfiguration.IPConfiguration</string>
        <key>CFBundleName</key>
        <string>SystemConfiguration</string>
        <key>CFBundleShortVersionString</key>
        <string>14.0.0</string>
        <key>DTCompiler</key>
        <string>com.apple.compilers.llvm.clang.1_0</string>
        <key>DTPlatformBuild</key>
        <string>6D97u</string>
        <key>DTPlatformVersion</key>
        <string>GM</string>
        <key>DTSDKBuild</key>
        <string>14C75a</string>
        <key>DTSDKName</key>
        <string>macosx10.10internal</string>
        <key>DTXcode</key>
        <string>0630</string>
        <key>DTXcodeBuild</key>
        <string>6D97u</string>
        <key>IPConfiguration</key>
        <dict>
                <key>ARPConflictRetryCount</key>
                <integer>2</integer>
                <key>ARPConflictRetryDelaySeconds</key>
                <real>0.75</real>
                <key>ARPDetectCount</key>
                <integer>3</integer>
                <key>ARPDetectRetryTimeSeconds</key>
                <real>0.014999999999999999</real>
                <key>ARPGratuitousCount</key>
                <integer>2</integer>
                <key>ARPProbeCount</key>
                <integer>3</integer>
                <key>ARPResolveRetryTimeSeconds</key>
                <real>0.32000000000000001</real>
                <key>ARPRetryTimeSeconds</key>
                <real>0.32000000000000001</real>
                <key>ConfigureIPv6</key>
                <true/>
                <key>DHCPAcceptsBOOTP</key>
                <false/>
                <key>DHCPAllocateLinkLocalAtRetryCount</key>
                <integer>4</integer>
                <key>DHCPFailureConfiguresLinkLocal</key>
                <true/>
                <key>DHCPInitRebootRetryCount</key>
                <integer>2</integer>
                <key>DHCPLeaseWriteT1ThresholdSeconds</key>
                <integer>3600</integer>
                <key>DHCPLocalHostNameLengthMax</key>
                <integer>15</integer>
                <key>DHCPRequestedParameterList</key>
                <array>
                        <integer>1</integer>
                        <integer>3</integer>
                        <integer>6</integer>
                        <integer>15</integer>
                        <integer>119</integer>
                        <integer>95</integer>
                        <integer>252</integer>
                        <integer>44</integer>
                        <integer>46</integer>
                </array>
                <key>dhcpoption60</key>
                <string>MSFT 5.0</string>
                <key>DHCPRouterARPAtRetryCount</key>
                <integer>7</integer>
                <key>DHCPSelectRetryCount</key>
                <integer>3</integer>
                <key>DHCPSuccessDeconfiguresLinkLocal</key>
                <true/>
                <key>DHCPv6Enabled</key>
                <true/>
                <key>DHCPv6RequestedOptions</key>
                <array>
                        <integer>23</integer>
                        <integer>24</integer>
                </array>
                <key>DefendIPAddressCount</key>
                <integer>5</integer>
                <key>DefendIPAddressIntervalSeconds</key>
                <integer>10</integer>
                <key>DiscoverAndPublishRouterMACAddress</key>
                <true/>
                <key>DiscoverRouterMACAddressTimeSeconds</key>
                <integer>60</integer>
                <key>GatherTimeSeconds</key>
                <integer>1</integer>
                <key>InitialRetryTimeSeconds</key>
                <integer>1</integer>
                <key>LinkInactiveWaitTimeSeconds</key>
                <real>0.10000000000000001</real>
                <key>ManualConflictRetryIntervalSeconds</key>
                <integer>300</integer>
                <key>MaximumRetryTimeSeconds</key>
                <integer>8</integer>
                <key>MinimumShortWakeIntervalSeconds</key>
                <integer>60</integer>
                <key>MinimumWakeIntervalSeconds</key>
                <integer>900</integer>
                <key>MustBroadcast</key>
                <false/>
                <key>RetryCount</key>
                <integer>9</integer>
                <key>RouterARPEnabled</key>
                <true/>
                <key>RouterARPWiFiLeaseStartThresholdSeconds</key>
                <integer>86400</integer>
                <key>UseMaintenanceWake</key>
                <true/>
                <key>WakeSkewSeconds</key>
                <integer>30</integer>
        </dict>
        <key>MachServices</key>
        <dict>
                <key>com.apple.network.IPConfiguration</key>
                <true/>
        </dict>
        <key>Requires</key>
        <array>
                <string>com.apple.SystemConfiguration.InterfaceNamer</string>
                <string>com.apple.SystemConfiguration.KernelEventMonitor</string>
                <string>com.apple.SystemConfiguration.PreferencesMonitor</string>
        </array>
</dict>
</plist>
Unfortunately no joy ... nothing has changed.
Does anybody have a solution to this problem or is it just no fixable ?
Thanks,
Matt.

found a solution : install dhcp (for example with darwinport , i.e. sudo port install dhcp) and use the dhclient command with a specific /etc/dhclient.conf
send dhcp-client-identifier "Guile";
send vendor-class-identifier "msft";
send host-name "GuileMac";

What to send in DHCP's Discover Option 61 Client identifier?

So i'm trying to use my own router, and it HAS TO include Option 61 "Client identifier" in it's DHCP Discover packet. But i noticed that if that option is included i don't get a DHCP Offer back from FiOS! I tried throwing my MAC in there but no love. What does FiOS expects to see in there? It's a very technical question so if i can't get help here how can i contact an engineer that would be able to answer this?
Thanks,
Alex

Welcome to the forums. Just so you know, this is a peer-to-peer support forum. Verizon does not answer questions here.
Sometimes the Verizon moderators escalate issues to the support team, which is an extension of the Verizon folk you can reach by using the "contact us" link at the bottom of these pages. If that happens to your issue, be sure to follow the instructions the moderators post.
Unfortunately, I do not know of any methods to reach Verizon's network engineers. They keep them very well separated from customers. Verizon keeps their residential customer contact very focused on the public support channels.
It's possible some of the other users here may know details about your question, but I'm not one of them.
Good Luck.
If a forum member gives an answer you like, give them the Kudos they deserve. If a member gives you the answer to your question, mark the answer as Accepted Solution so others can see the solution to the problem.

Need help with client identifier & DHCP

I have created static hosts for all of my clients (interim measure until I get DNS servers built and running) on an SG300-20. I defined all of these allocations using MAC addresses.
However, several of my clients (1 Windows 7 workstation, 2 FreeNAS / FreeBSD storage servers and 1 HP color Laserjet printer) are still being dynamically assigned other addresses based on client identifier.
In all four cases, the client identifier being used by the switch is the MAC address with a leading "01" octet attached.
For example, my workstation has a MAC address of 00:10:18:E3:64:2F, which is defined as a static host based on that MAC address. The switch is using a client identifier of 01:00:10:18:E3:64:2F.
I am sure that I need to be entering a client identifier in the static host instead of the MAC address. From the discussions that I have read on here, that should look something like 0100.1018.e364.2f, but the static hosts GUI will not accept that. It won't allow me to type periods at all, and it won't accept 0100:1018:e364:2f, so I am clearly not entering this correctly.
Any help on how to resolve this / how the GUI is expecting the client identifier to be formatted?
Thanks!

To me that's a bug. You can't know how to enter a host into the static bind table until you know whether it wil provide a client id. Like you said if you enter a MAC and comes up with a client id it doesn't recieve the assigned ip, if you assume the client id based on 01+MAC and it doesn't end up presenting a client id again the host doesn't get the assigned ip.
For years with dumber switches I could take a list of MACs and enter them on my switches so that when a device came online if their default was dhcp it would obtain the address I wanted and I'd know where to find it. Now with these "smarter" switches I have to work harder so in some regards these switches are dumber than an Best Buy off the shelf switch.
You should be able to fill in the MAC value and the switch should auto-complete the client id assuming a 01 prefix that cna be changed. Both values should be editable and maintained in their own tables for each host entry.

WRT54G v7 WAN DHCP client problem

I've recently started having a strange problem with my WRT54G. Internet access is via a Cable modem and has been working fine for months, and the cable modem works fine so I suspect the problem is with the router. However the router is also working, mostly, so I figured I'd see if anyone here has any suggestions. Here are the details of the problem:
The router WAN configuration was set to DHCP.
It used to happily pick up a new IP address from the cable modem whenever necessary.
One night the router stopped picking up an IP on the WAN side. (nothing was changed. I'm the only one in the house who goes anywhere near the router)
Connecting the modem directly to a PC works fine (suggesting the modem's DHCP server is fine).
Copying the WAN IP config from the PC to the router, as a Static IP, also allows it to work when the modem is plugged back into the router and the router to a PC (which is how it's setup now, but it's a pain to have to mess with the physical connections and manually reconfigure the router every time the modem drops a connection (which is another issue, but not one for this forum...)).
So both the modem and the router seem to work except for the router's DHCP client. It works fine as a DHCP server for the LAN.
The firmware was already upgraded (and working), I've followed the standard power-cycle procedure, I've released and renewed the IP via the Status tab in the web interface, and I've tried resetting the router using both the button on the unit and via the web interface to revert to factory defaults.
Any suggestions?
Solved!
Go to Solution.

I also had this problem which occurred after >2 years of the router working fine. After changing MTU to 1300, cloning the PC MAC address, and power cycling the router and modem fixed the problem. But I was curious to see which change did the trick, so I changed both back to the default (MTU = auto and not cloning the MAC address) and it worked fine! I think the router problem is intermittant and may appear to be fixed by changing setting, but I fully expect it to reoccur.

Win7 dhcp client: sending options

I am trying to change dhcp option 60 and 43 on my Windows 7 Cleint PC.
The standard option 60 - vendor class identifier is set to "MSFT 5.0" and I would like to change it to a different value of "Siemens". Similarly I want to send a Vendor Specific ID using option 43.
I have tried to add:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DHCP\Parameters\Options\DhcpSendOptions
"60"=hex:3c,07,53,69,65,6d,65,6e,73
but try as I will, it will not send anything modified in the DHCP client request to the server.
Do I need to put the registry entry somewhere else or in a different format?
Thanks.

Hi,
After research, I found this registry key was supported by Windows CE and may not be supported in Windows 7. Otherwise, I have not found any documents that mentioned this.
Juke Chou
TechNet Community Support

Setting options in DHCP client ...

Hi everyone, ...
Im having problems connecting to my corporate intranet DHCP network and investigating I realize the DHCP server requires a fixed DHCP Option 60 (vendor-class-identifier) with the value "MSFT 5.0".
Please, How can I configure this option in my osx DHCP client?
Regards,
Raul.

So you Mac is supporting Windows 2000 or older Microsoft operating systems? That is what Microsoft DHCP Vendor and User Classes. The 10.6.x system shouldn't need and changing.

DHCP client does not work poperly after systemd and Gnome 3.6 upgrade

Upgraded my system today from Gnome 3.4 to 3.6 (and systemd was updated as well), and since then acquiring an IP address using DHCP does not work anymore.
I am using IPv4 only internally, but neither dhclient or dhcpcd manages to get an IPv4 address.
It seems like IPv6 is priority one, and beacuse there is no IPv6 DHCP server available NetworkManager aborts the whole setup process.
To make sure that IPv6 should not be considered, I have changed "method" in NetworkManager to "Ignore" for IPv6.
I have also tried to downgrade NM to 0.9.6.0 from 0.9.6.4 (since that version works on another, not upgraded, machine), without any result.
Also switched dhclient to dhcpcd, without any result.
The machine is a "pure" systemd machine.
DHCP works for other devices in the network.
Versions:
systemd 195-2
NetworkManager 0.9.6.4
isc-dhclient-4.2.3-P2
I have no issues on a system where following versions are running:
systemd 189-4
NetworkManager 0.9.6.0
dhcpcd 5.6.2
Log: http://pastebin.com/2wMC0JLe

Think I have identified the issue now.
Neither dhcpcd or dhclient is sending the host name properly to the DHCP server anymore. I had an IP address reserved in the DHCP server for my host and after deleting this reservation my host is able to acquire an IP (dynamic) address. The reserved static address could never be acquired.
Conclusion: dhclient and dhcpcd is not sending the host name as before, causing the DHCP server to get stuck (while waiting for the host name) whenever a NIC with a reserved IP address is requesting an IP address.
Downgrading the dhcp clients has not yet worked, so there might be some underlying component that is causing the problem. ath5k? systemd?

Client Identifier and MAC addresses

Hello Everyone,
I am migrating my DHCP services from an old SUN server to an OES Linux server. In the old SUN files, my client identifier and mac addresses have a leading pair. So if my mac address is 00:30:C1:57:44:09, it is entered in the SUN files like this: 01:00:30:C1:57:44:09. My question is, do I need to enter that extra pair in my host records for OES Linux DHCP? If I do or don't, does it matter?
The reason I'm asking is that many of my older printers and even some of the newer ones are not picking up an address from the new DHCP server when the old one expires.
Thanks,
Toney.

On 21/06/2010 19:46, toneyc wrote:
> I am migrating my DHCP services from an old SUN server to an OES Linux
> server. In the old SUN files, my client identifier and mac addresses
> have a leading pair. So if my mac address is 00:30:C1:57:44:09, it is
> entered in the SUN files like this: 01:00:30:C1:57:44:09. My question
> is, do I need to enter that extra pair in my host records for OES Linux
> DHCP? If I do or don't, does it matter?
Whilst I've seen this with NetWare-based DHCP the DHCP on OES Linux uses
different objects and is provided by ISC DHCP which does not have this -
my DHCP hosts are configured just with MAC address.
If you examine a dhcpHost object in ConsoleOne - clicking the Other tab
should show the dhcpHWAddress attribute has the value "ethernet
01:23:45:67:89:ab" (where 01:23:45:67:89:ab is MAC address).
> The reason I'm asking is that many of my older printers and even some
> of the newer ones are not picking up an address from the new DHCP server
> when the old one expires.
Just printers or other types of devices too?
If printers, particularly HP ones, check that they're set to pick up IP
details via DHCP and not BOOTP. Yes should still work but we've seen
problems here.
HTH.
Simon
Novell Knowledge Partner (NKP)
Do you work with Novell technologies at a university, college or school?
If so, your campus could benefit from joining the Novell Technology
Transfer Partners (TTP) group. See www.novell.com/ttp for more details.

WDS PXE DHCP, Clients on different subnet

Hello,
We are having a lot of trouble trying to get pxe imaging working from our WDS server on different subnets. We have an existing Zenworking imaging setup working as of right now, but WDS is causing more issues than I care to troubleshoot. I have read
blog after blog, forum post after forum post and everyone says just install it and it works! I guess we have run into some sort of problem that nobody else has.
Enviroment:
2x DC's, Server 2012 R2, both run DNS, 10.5.0.101, 10.5.0.102
1x DHCP Server, 2012 R2, 10.5.0.105
1x WDS Server, 2012 R2, 10.5.0.41
If I put a client on the same subnet as all of the servers it seems to work, except for the fact that it takes a while for the client to get an IP and continue to load wdsnbp.com. I would say around 20-30 seconds. In our zenworks enviroment it takes
no more than 1 second to get an IP. As for the dhcp server itself, clients receive normal dhcp offers instantly. So that part is working properly.
Now when I try an access the WDS pxe server from a different subnet other than the one that all of the servers are on, noting that I do have the ip helper address setup on our layer 3 switch:
interface Vlan2025
ip address 10.200.20.1 255.255.255.0
ip helper-address 10.5.0.105
ip helper-address 10.5.0.41
It always says failed to receive boot file. But as I said earlier, clients in windows receive dhcp leases from 10.5.0.105 without issue.
Setting the client options in the DHCP server with options 66 and 67 works sortof, but we found that it was unreliable and often finicky. Like having the system repeatedly ask to press f12, and even if you did press f12 it would still ask to press f12
again.
So I continued to do a wirehark packet capture on the port where the device was trying to get the dhcp/pxe info from the DHCP / WDS servers. The first packet here is from the DHCP server and the second is from the WDS server.
Bootstrap Protocol
Message type: Boot Reply (2)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 0
Transaction ID: 0xd6c565d2
Seconds elapsed: 0
Bootp flags: 0x8000 (Broadcast)
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 10.200.20.117 (10.200.20.117)
Next server IP address: 10.5.0.105 (10.5.0.105)
Relay agent IP address: 10.200.20.1 (10.200.20.1)
Client MAC address: Hewlett-_c5:65:d2 (78:e7:d1:c5:65:d2)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type
Length: 1
DHCP: Offer (2)
Option: (1) Subnet Mask
Length: 4
Subnet Mask: 255.255.255.0 (255.255.255.0)
Option: (58) Renewal Time Value
Length: 4
Renewal Time Value: (21600s) 6 hours
Option: (59) Rebinding Time Value
Length: 4
Rebinding Time Value: (37800s) 10 hours, 30 minutes
Option: (51) IP Address Lease Time
Length: 4
IP Address Lease Time: (43200s) 12 hours
Option: (54) DHCP Server Identifier
Length: 4
DHCP Server Identifier: 10.5.0.105 (10.5.0.105)
Option: (3) Router
Length: 4
Router: 10.200.20.1 (10.200.20.1)
Option: (6) Domain Name Server
Length: 8
Domain Name Server: 10.5.0.101 (10.5.0.101)
Domain Name Server: 10.5.0.102 (10.5.0.102)
Option: (15) Domain Name
Length: 8
Domain Name: domain.com
Option: (255) End
Option End: 255
Bootstrap Protocol
Message type: Boot Reply (2)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 0
Transaction ID: 0xd2c565d2
Seconds elapsed: 4
Bootp flags: 0x8000 (Broadcast)
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 10.5.0.41 (10.5.0.41)
Relay agent IP address: 10.200.20.1 (10.200.20.1)
Client MAC address: Hewlett-_c5:65:d2 (78:e7:d1:c5:65:d2)
Client hardware address padding: 00000000000000000000
Server host name: wds1.domain.com
Boot file name not given
Magic cookie: DHCP
Option: (54) DHCP Server Identifier
Length: 4
DHCP Server Identifier: 10.5.0.41 (10.5.0.41)
Option: (97) UUID/GUID-based Client Identifier
Length: 17
Client Identifier (UUID): eb8daa31-8e62-11df-bbd8-d1c565d278e7
Option: (60) Vendor class identifier
Length: 9
Vendor class identifier: PXEClient
Option: (53) DHCP Message Type
Length: 1
DHCP: Offer (2)
Option: (255) End
Option End: 255
What I find interesting is that the WDS server is not handing out a boot file name:
"Boot file name not given"
Could this be the reason why we receive the no boot file received error when trying to boot a client into pxe?
The other thing that I noticed was that the WDS server is also responding with the:
" Option: (60) Vendor class identifier
Length: 9
Vendor class identifier: PXEClient
Why would it be responding with this, when the dhcp is on a separate server. Is this option only if you have DHCP and WDS on the same server?
Any help would be appreciated as there has been too much time already spent on getting nowhere.
Thanks,
Dan.

Dan,
10 months later and not one reply... I'm having the same issue, did you ever figure this out? DHCP server is my Cisco Switch, WDS/PXE is on another network. The WDS and PXE is working fine as I can do so from the same network as the WDS/PXE
server. I can also get the WDS/PXE to work if I have a MS DHCP server on a different network and populate the option 66 and option 67. I cannot get this to work using Cisco ip helper-address for some reason.
Thanks,

I want to reserve a static IP address on my Airport extreme. What is the difference between reserving by MAC Address and DHCP Client ID?

I want to understand the differences in the way you can reserve a static address for a device on the network. I had previously set the device itself to an address and then reserved it with DHCP Client ID, which I thought was just the devices static addresss. I'm not sure if this was in fact correct or just happend to work. I know what a MAC address is, but I'm not really sure what the DHCP Client ID is. So it would be great if someone could clarify it, and the difference between reserving address by MAC Address or DHCP Client ID.

A MAC address is a unique identification consisting of letters and numbers in a form that looks like this:
xx:xx:xx:xx:xx:xx
Every network device has a MAC address, which can be found on a label on the bottom or back of the device. Apple calls this the Ethernet ID.
A DHCP Client ID is an optional name that you can assign to a device. For example, on your Mac....
Open System Preferences (gear icon on the dock)
Open Network
Click on Ethernet
Click Advanced at the lower right
You may be able to edit the DHCP Client ID here....for example.....you could enter MJ500's MacBook in the space provided. That would be the Client ID of your Mac.

Cisco ASA 5505 and DHCP Client Problems

Hi, i have a problem. I've connected my ASA appliance to an ADSL modem, and i dont get an DHCP address on the outside interface (e0/0). I use the asa-722-19.bin firmware.
I turned on the debugging for the DHCP client and could see that the ASA device was sending out broadcasts but a reply never came. Instead I connected the device to my internal network where the ASA got an address instantly.
I read somewhere that if I was to use ?ip address dhcp client-id fastethernet 0″, then I got an address from the ISP.
I tried looking for a similar command on the ASA5505 but I couldn?t find anything. I did however find a page on the Cisco site confirming my suspicions. It said some ISP?s require the client-id field of the DHCPDISCOVER request to be filled.
I've also read that this issue has beed fixed since a few weeks, now they have released version 7.2(2).22 where you can define ?dhcp-client client-id interface outside? in global configuration mode. Im running 7.2(2).19 and i cannot find any command like that in my appaiance. How do i fix my problem ? Or how do i get about recieving the 7.2(2).22 firmware update.
Regards !
Leif

Hi again! I thought I should share the solution that worked for me. I use software version 7.2(2) on this device. ASDM 5.2(2). In ASDM open configuration / Interfaces. Click in outside (my case 0/0) and press Edit. Then open the tab Advanced and set the correct Active Mac address. Fore some reason its empty by default and the ISP/modem don't like that. You will find the correct MAC address under the help menu / "About ASA". Im sure there is some another way to do this but this is a simple "how-to" that works with Swedens biggest ISP and their standard DSL modem.
When I used a Linksys DSL modem in bridge mode without the MAC address set I got an inside IP adress (192.168.x.x) from the modem to the ASA. After setting the MAC address I just had to do a renew and got the outside address right away. /Bjorn
(future users searchwords: no ip from isp, ASA 5505 and cable modem).

Strange DHCP client identifier

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