Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

DHCP based Auto Configuration in 2950

I have a 2950-24 Switch. With IOS 12.1(19)EA1.

Trying to follow this link, to do a DHCP based auto configuration of the switch, which is not working as expected.

The file network-confg file was created with host to IP mappings on the TFTp server default directory. The file looks like this.

ip host switch1

ip host switch2

ip host switch3

Also the original Switch configuration files are also present in the same folder. "switch1-confg", "switch2-confg" etc...

The Switch1 had no ip address configured on vlan 1, and it also has "service config" enabled. When the switch boots up, it doesnt acquire a DHCP address as specified by the document. It also pops up with the following errors.

%Error opening tftp:// (Socket error)

%Error opening tftp:// (Socket error)

%Error opening tftp:// (Socket error)

%Error opening tftp:// (Socket error)

The DHCP server is a router with IP address A host pool has been created in the router to manually bind the switch mac address to its ip address.

ip dhcp excluded-address

ip dhcp excluded-address


ip dhcp pool test


hardware-address 000e.38a0.4880

bootfile switch1-confg

option 66 ip

Here, is the router itself, is the TFTP server, is the ip address that is supposed to be leased to the Switch1.

Nothing seem to work as expected. Have I missed something here ? Anybody who has done this kind of setup, please throw in your experiences.

PS: I also have noticed the following bug in 12.0(5)WC3 images on 2950. Bug ID is CSCds58369.

Bug Description - If the switch gets configured from the dynamic IP pool, a duplicate or different IP address might be assigned.

The workaround is to make sure that the DHCP server contains reserved addresses that are bound to each switch by the switch hardware address so that the switch does not obtain its IP address from the dynamic pool.

If you note my configuration, the mac address of the switch has been manually binded to the ip address



Re: DHCP based Auto Configuration in 2950

Just wondering if the TFTP server has to be represented by a name and DNS should be configured to resolve it to IP address. You can probably use 'debug dhcp detail' or 'debug ip dhcp server events' on the DHCP server to see the messages being exchanged.