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DHCP snooping problem on 5300xl

 
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pt307
Advisor

DHCP snooping problem on 5300xl

Hi,

I've enabled dhcp-snooping on a 5300xl switch running the E.11.21 firmware and configured it to write the database to a tftp server at 15 minute intervals (the tftp server is on the Default VLAN). The snooping itself is working, but the switch is not writing the database - I'm seeing this behaviour on 3 different 5300xl switches.

This is how I configured it:
Switch(config)# no dhcp-snooping option 82
Switch(config)# dhcp-snooping vlan 3 5 11 12 17
Switch(config)# interface A1,B24 dhcp-snooping trust
Switch(config)# dhcp-snooping database file "tftp://xxx.xx.xx.69/switch.dhcp" delay 900
Switch(config)# dhcp-snooping
Switch(config)# wr mem

This is the 'show dhcp-snooping' output:
DHCP Snooping Information

DHCP Snooping : Yes
Enabled Vlans : 3 5 11-12 17
Verify MAC : Yes
Option 82 untrusted policy : drop
Option 82 Insertion : No

Store lease database : Yes
URL : tftp://xxx.xx.xx.69/switch.dhcp
Read at boot : no
Write delay : 900
Write timeout : 300
File status : delaying
Write attempts : 0
Write failures : 0
Last successful file update :

There are currently around 25 leases in the binding table. I've set it up in the same way on a 5400zl switch and that works fine. I've also confirmed the switch can write to the tftp server by running a copy command-output.

Has anyone else had problems with this on a 5300?

Ta,

Paul
5 REPLIES 5
Shadow13
Respected Contributor

Re: DHCP snooping problem on 5300xl

Make sure you can ping the TFTP server IP address from the switch.

Also make sure that the TFTP service is working.

ProCurve Switch 5308xl(config)# tftp
client Enable/Disable tftp client
server Enable/Disable tftp server
pt307
Advisor

Re: DHCP snooping problem on 5300xl

Hi Shadow,

I can ping the tftp server from the switch, and I tried the tftp client and tftp server commands in config mode, but it's made no difference.

The file status is still 'delaying' and there's been 0 write attempts.

Thanks.
Shadow13
Respected Contributor
Solution

Re: DHCP snooping problem on 5300xl

Write attempts : 0
Write failures : 0

It didn't even tried to write...

Try changing the delay to the least amount and check.

Also post the same output from the 5406zl switches you have please "show dhcp-snooping)
pt307
Advisor

Re: DHCP snooping problem on 5300xl

Hrm, changing the delay to 15 seconds made it write successfully!

Odd but I'll play with it some more :)

Thanks!
Shadow13
Respected Contributor

Re: DHCP snooping problem on 5300xl

Good to know, it might be related to the delay on the TFTP server itself, i think some how they have to be in the same range or something like that not sure :P