topic Re: DHCP relay on asa issue in Network Security

DHCP relay on asa issue

ahmed.gadi — Mon, 11 Mar 2019 20:35:07 GMT

Hi all,

I am facing problem configuring dhcp relay on asa 5520. I have refered this document from cisco.com

http://www.cisco.com/en/US/products/ps6120/products_configuration_example09186a008075fcfb.shtml

I have windows DHCP server and AIP-SSM configured inline mode.

In AIP-SSM DHCP OFFER,REQUEST and REPLY are categorized as medium risk and default action is alert only, i changed to log only.

I can not see any traffic between DHCP Server and client on ASA via logging.

Does someone have came accross this type of problem ?

Regards

Ahmed...

Re: DHCP relay on asa issue

Maykol Rojas — Wed, 18 May 2011 18:22:12 GMT

Hello,

Can you take a packet capture on the ASA firewall, also, can you check if bypassing the AIP it workes? The packet capture would be like this:

capture asp type asp-drop all

Try to release/renew and get the output of

show cap asp

Let me know.

Mike

Re: DHCP relay on asa issue

ahmed.gadi — Wed, 18 May 2011 18:59:20 GMT

thanks mike,

let me see tomorrow, i will update you.

Regards

Ahmed...

Re: DHCP relay on asa issue

ahmed.gadi — Mon, 23 May 2011 10:55:46 GMT

Hi Mike,

Please find the attached asp output.

I tried to bootpc with mac address 0:3:ba:c:3:3d, and i found one entry in sh capture related to it.

45: 13:29:23.556581 802.1Q vlan#60 P0 rarp who-is 0:3:ba:c:3:3d tell 0:3:ba:c:3:3d Drop-reason: (l2_acl) FP L2 rule drop

I really want to know if this action has taken by AIP-SSM ? ( i have not removed AIP till now).

Customer is very much concern about the securtiy of the network and can drop the plan of configuring dhcp-relay over ASA, if i need configuration changes to AIP and is affecting security. Can cisco provide any recommendation for this ? or i need to open TAC for more clarification.

Please let me know....

Thanks & Regards

Ahmed...

Re: DHCP relay on asa issue

ahmed.gadi — Mon, 23 May 2011 10:57:22 GMT

I have taken output for following

show asp drop

show asp table arp

show asp table classify

show asp table interfaces

show asp table routing

if you need the output of above please let me know i can provide as well.

Regards

Ahmed...