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DHCP Snooping issue

Jhonadms
Level 1
Level 1

Hi All,

 

I am getting below error in bulks please advise.

 

DHCP_SNOOPING: DHCP packet may be headed in the direction of the relay x.x.x.x.

 

Jhon

6 Accepted Solutions

Accepted Solutions

Hi Jhon,

 

May i know the platform and IOS version, where your getting the error message, 

*** Please rate all helpful responses and mark solutions***

View solution in original post

Thank you! 

 

Please answer the following questions!

1) What is the impact of this error?

2) Have you made any changes recently?

3) What is the RSP you have?

 

 

 

 

*** Please rate all helpful responses and mark solutions***

View solution in original post

Andrew Khalil
Spotlight
Spotlight

@Jhonadms Greetings,

You will need just to disable the information option that is enabled by default, to do so please type the following command:

#no ip dhcp snooping information option

That's it! 

 

Please don't forget to rate all helpful responses and mark solutions!

Bst Rgds,

Andrew Khalil

View solution in original post

Hi Jhon,

 

The Error error messages which you see seem to be an informational message and not traffic impacting one.

 

A Cisco device  may log the following informational message regularly:

 

DHCP_SNOOPING: DHCP packet may be headed in the direction of the relay x.x.x.x, 

not extracting option82 information

This can be seen if the dhcp snooping is enabled on the device. These logs are being generated while device unable to suppress DHCP snooping debug output.

 

As a workaround, you may try out removing the option 82 from DHCP snooping. The command for the same is 

 

" No ip dhcp snooping information option "

 

BR,

Tayyab - www.tayyabmunir.com 

 

 

 

 

*** Please rate all helpful responses and mark solutions***

View solution in original post

@Jhonadms

 

Happy to heard that I helped you.

 

BR!

Tayyab 

 

 

*** Please rate all helpful responses and mark solutions***

View solution in original post

@Jhonadms

Greetings, Happy that my solution helped! 

Also @MUHAMMAD TAYYAB MUNIR has repeated just the same! 

 

Just for your info., when the DHCP snooping option-82 feature is enabled on the switch, a subscriber device is identified by the switch port through which it connects to the network (in addition to its MAC address). Multiple hosts on the subscriber LAN can be connected to the same port on the access switch and are uniquely identified. Some DHCP server (and I guess also the IOS DHCP server) doesn't support this option which can cause to generate that log!

 

Please don't forget to rate all helpful responses and mark solutions!

Bst Rgds,

Andrew Khalil

View solution in original post

10 Replies 10

Hi Jhon,

 

May i know the platform and IOS version, where your getting the error message, 

*** Please rate all helpful responses and mark solutions***

@MUHAMMAD TAYYAB MUNIR

 

IOS: Version 15.2(4)S4a

Platform: CISCO7609-S

 

Jhon

Thank you! 

 

Please answer the following questions!

1) What is the impact of this error?

2) Have you made any changes recently?

3) What is the RSP you have?

 

 

 

 

*** Please rate all helpful responses and mark solutions***

@MUHAMMAD TAYYAB MUNIR

 

1) Missing impotent logs 

2) Not remembered

3) RSP720-3C-GE

 

Jhon

Hi Jhon,

 

The Error error messages which you see seem to be an informational message and not traffic impacting one.

 

A Cisco device  may log the following informational message regularly:

 

DHCP_SNOOPING: DHCP packet may be headed in the direction of the relay x.x.x.x, 

not extracting option82 information

This can be seen if the dhcp snooping is enabled on the device. These logs are being generated while device unable to suppress DHCP snooping debug output.

 

As a workaround, you may try out removing the option 82 from DHCP snooping. The command for the same is 

 

" No ip dhcp snooping information option "

 

BR,

Tayyab - www.tayyabmunir.com 

 

 

 

 

*** Please rate all helpful responses and mark solutions***

@MUHAMMAD TAYYAB MUNIR

 

Thank you for providing the detailed solution, its help me to justify with my team lead.

 

Cheers

Jhon

@Jhonadms

 

Happy to heard that I helped you.

 

BR!

Tayyab 

 

 

*** Please rate all helpful responses and mark solutions***

Andrew Khalil
Spotlight
Spotlight

@Jhonadms Greetings,

You will need just to disable the information option that is enabled by default, to do so please type the following command:

#no ip dhcp snooping information option

That's it! 

 

Please don't forget to rate all helpful responses and mark solutions!

Bst Rgds,

Andrew Khalil

@Andrew Khalil

 

Can you provide more details about this error message why it was not appearing before and recently started, what is the changes can  triggered this error.

 

 

Jhon

 

@Jhonadms

Greetings, Happy that my solution helped! 

Also @MUHAMMAD TAYYAB MUNIR has repeated just the same! 

 

Just for your info., when the DHCP snooping option-82 feature is enabled on the switch, a subscriber device is identified by the switch port through which it connects to the network (in addition to its MAC address). Multiple hosts on the subscriber LAN can be connected to the same port on the access switch and are uniquely identified. Some DHCP server (and I guess also the IOS DHCP server) doesn't support this option which can cause to generate that log!

 

Please don't forget to rate all helpful responses and mark solutions!

Bst Rgds,

Andrew Khalil

Review Cisco Networking for a $25 gift card