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

[andbor600]

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

[andbor600]

the problem solved.

I removed client name entry in host IP definition. now my switch assigns the correct IP addresses to my host based on clinet identifier.

just wonder what this field is for. not to mention I had to remove the client name using CLI. web functionality cannot manage it.

[Aleksandra Dargiel]

Hi Andbor600,

Please note the difference between host name and client name on gui as well as cli.

While the first one is obligatory but has local meaning only, the second is optional and really depends on what options are sent with DHCP request.

I guess the easier way to understand all of those identifiers (client name, client id and hardware address) is to capture packets (using Wireshark) when client is obtaining IP address from the dhcp server and filter bootp protocol.

Regards,

Aleksandra

[Richard H. Shores]

Although this issue was posted a year ago, I was having the same problem with my SG300. Removing the client name entry fixed the issue for me as well. Cisco makes some good small business switches. However, the documentation, and to be quite candid, is terrible. 

[libor.nenadal]

I think that it is very unfortunate situation with dynamic configuration having higher priority than static. I experience the same on EPC3925. :-( Was this issue fixed already? I have firmware

epc3925-ESIP-12-v302r125572-130412c_upc (seems like it has some changes made by provider)...

[Aleksandra Dargiel]

Hi Libor,

Please note that this is post for Small Business managed switch and your modem does not follow under.

I checked also that those devices are supported directly by service provider so I guess the best answer you can get from your service provider directly.

Please find below link where on the bottom of the page you can choose your service provider and get redirected to the correct website with their contact details.

http://www.cisco.com/web/consumer/support/modem_DPC3925.html#~troubleshooting

Aleksandra

[mateicon]

Hello,

After 6 years I'm renewing this post .... :-( ... so I need your help please.
I have the latest firmware 1.4.9.4 on my home SF308 switch. 

My DHCP static reservations are still not working after rebooting both the switch and the laptop.

Here is my DHCP config:

ip dhcp server
ip dhcp pool host laptop-hp
address 172.17.19.61 255.255.255.0 client-identifier 01:00:26:c6:c5:4c:5c
exit
ip dhcp pool host ipad
address 172.17.19.62 255.255.255.0 client-identifier 01:24:24:0e:69:e8:c6
exit
ip dhcp pool network "dhcp_pool_guest"
address low 172.17.19.51 high 172.17.19.69 255.255.255.0
default-router 172.17.19.2
dns-server 172.17.17.1
exit

[mateicon]

Hi,

I made it working after couple more switch and laptop reboots and by adding the options for "default-router" and "dns-server".
It's working now!

ip dhcp server
ip dhcp excluded-address 172.17.19.51 172.17.19.52
ip dhcp pool host laptop-hp
address 172.17.19.51 255.255.255.0 client-identifier 01:00:26:c6:c5:4c:5c
default-router 172.17.19.2
dns-server 172.17.17.1
exit
ip dhcp pool network "guest"
address low 172.17.19.51 high 172.17.19.59 255.255.255.0
default-router 172.17.19.2
dns-server 172.17.17.1
exit