Catalyst 3750E and DHCP Snooping

Rreyore — Tue, 14 Jun 2011 18:19:29 +0000

We are using 3750E’s and 4500R model switches on our perimeter with DHCP snooping enabled. We have a central DHCP server and all of the switches write their databases off to a central TFTP server.

example: ip dhcp snooping database tftp://

This was working fine until the day we upgraded our domain and dchp server to 2008 active directory. After that, the 3750E’s no longer update their database’s on the tftp server. The 4500R’s however are still working.

example:

Cisco 3750E

show ip dhcp snooping database Agent URL : tftp://

Write delay Timer : 3600 seconds Abort Timer : 300 seconds

Agent Running : No Delay Timer Expiry : 0 (00:00:00) Abort Timer Expiry : Not Running

Last Succeded Time : None Last Failed Time : None Last Failed Reason : No failure recorded.

Total Attempts : 0 Startup Failures : 0 Successful Transfers : 0 Failed Transfers : 0 Successful Reads : 0 Failed Reads : 0 Successful Writes : 0 Failed Writes : 0 Media Failures : 0

Cisco 4507R

show ip dhcp snooping database Agent URL : tftp://

Write delay Timer : 3600 seconds Abort Timer : 60 seconds

Agent Running : No Delay Timer Expiry : 1443 (00:24:03) Abort Timer Expiry : Not Running

Last Succeded Time : 12:49:48 EDT Tue Jun 14 2011 Last Failed Time : None Last Failed Reason : No failure recorded.

Total Attempts : 2 Startup Failures : 0 Successful Transfers : 2 Failed Transfers : 0 Successful Reads : 0 Failed Reads : 0 Successful Writes : 2 Failed Writes : 0 Media Failures : 0

Has anybody else seen this and is this a software bug? It is not just one 3750E that did this but all of them (12 stacks of them). All 5 4500R’s are working just fine.

IT Answers » Catalyst 3750-E

Catalyst 3750E and DHCP Snooping