topic Re: Ip address assignment via DHCP for an anyconnect client in Network Security

Ip address assignment via DHCP for an anyconnect client

jeyriku — Fri, 21 Feb 2020 10:03:30 GMT

Hi,

On my Asa(with asdm)i configured the DHCP server in the managment tab to allow dynamic Ip assignment for my lan devices (on the inside interface). I tried to allow Ip assignement via my Lan DHCP server for my VPN SSL client located on a remote site but it didn't work (they mount the tunnel on the outside interface of the Asa). I would have liked to know if someone could advise me to do so. When i checked the DHCP box in the different connection profiles my client still didn't receive any address. Are there anything i need to allow to perform this action. I hope someone can help.

PS: Here is the message i get when i start the Cisco anyconnect client:

"An error was received from the secure gateway in response to the vpn negociation request. Please contact your network administrator. The following message was received from the remote VPN device: No assigned Address"

Best regards.

Re: Ip address assignment via DHCP for an anyconnect client

owillins — Tue, 17 Jun 2008 19:03:46 GMT

The error message indicates that the ASA returned an HTTP error to the client when the client attempted to establish an SSL connection.

Re: Ip address assignment via DHCP for an anyconnect client

jeyriku — Tue, 17 Jun 2008 20:14:27 GMT

I understand this To. But deeper, it means that my Lan DHCP server can't deliver IP address to my VPN SSL client. I don't understand why!! As long as you check the "DHCP" box it should work, but at the moment it doesn't. Can you help me?

Best Regards,

Re: Ip address assignment via DHCP for an anyconnect client

Farrukh Haroon — Wed, 18 Jun 2008 12:12:00 GMT

Can you post output of webvpn debugs?

Regards

Farrukh

Re: Ip address assignment via DHCP for an anyconnect client

jeyriku — Wed, 18 Jun 2008 13:27:43 GMT

Here is a copy of syslog entries which best describe what is happening:

"Device completed SSL handshake with client outside: X.X.X.X:XXXX"

"TunnelGroup GroupPolicy User IP No address available for SVC connection"

The SSL connection starts without problems, but as soon as i need to be assigned an ip address, it doesn't work. The odd thing is that in both profile the DHCP box is checked.

Can someone help?

Best regards

Re: Ip address assignment via DHCP for an anyconnect client

Farrukh Haroon — Wed, 18 Jun 2008 13:31:22 GMT

Can you post the webvpn related CLI configuration?

Regards

Farrukh

Re: Ip address assignment via DHCP for an anyconnect client

jeyriku — Wed, 18 Jun 2008 13:45:17 GMT

Hi, here is what you asked me for:

webvpn

enable inside

enable outside

csd image disk0:/securedesktop-asa-3.2.1.103-k9.pkg

svc image disk0:/anyconnect-win-2.2.0128-k9.pkg 3

svc enable

cache

max-object-size 5000

group-policy DfltGrpPolicy attributes

dns-server value X.X.X.X

dhcp-network-scope X.X.X.X

vpn-tunnel-protocol IPSec l2tp-ipsec svc webvpn

default-domain value XXXXXX

intercept-dhcp 255.255.255.XXX enable

nac-settings value DfltGrpPolicy-nac-framework-create

webvpn

url-list value Lan_Applications

svc keepalive none

svc dpd-interval client none

svc dpd-interval gateway none

svc ask enable default webvpn

customization value DfltCustomization

tunnel-group DefaultRAGroup general-attributes

authentication-server-group (outside) LOCAL

authorization-server-group LOCAL

authorization-server-group (outside) LOCAL

dhcp-server XXX.XXX.XXX.XXX

tunnel-group DefaultWEBVPNGroup general-attributes

authentication-server-group (outside) LOCAL

authorization-server-group LOCAL

authorization-server-group (outside) LOCAL

dhcp-server XXX.XXX.XXX.XXX

authorization-required

Best Regards,

Jeyriku

Re: Ip address assignment via DHCP for an anyconnect client

Farrukh Haroon — Wed, 18 Jun 2008 18:29:33 GMT

Do you have the following in your configuration:

"vpn-addr-assign dhcp"

Note: DHCP assignment is disabled by default

Regards

Farrukh

Re: Ip address assignment via DHCP for an anyconnect client

jeyriku — Wed, 18 Jun 2008 19:41:04 GMT

Hi,

Many thanks for your response

No it doesn't appear but it should as i already typed it before

But the following appear:

"no vpn-addr-assign aaa

no vpn-addr-assign local"

Do you have an idea why it doesn't appear?

Best regards,

Re: Ip address assignment via DHCP for an anyconnect client

Farrukh Haroon — Thu, 19 Jun 2008 00:49:24 GMT

No that is ok, it means AAA and LOCAL are now disabled, and DHCP is enabled.

Can you post more aggressive debugs?

Regads

Farrukh

Re: Ip address assignment via DHCP for an anyconnect client

jeyriku — Thu, 19 Jun 2008 06:55:10 GMT

Hi,

Can you tell me what i need to do? What do you mean by "more agressive"?

kind Regards,

Re: Ip address assignment via DHCP for an anyconnect client

Farrukh Haroon — Thu, 19 Jun 2008 07:03:53 GMT

I meant more detailed/verbose debugs, please attach the output of the following:

debug dhcpd event

debug dhcprelay event

debug webvpn tunnel

debug webvpn svc

debug webvpn html

Regards

Farrukh

Re: Ip address assignment via DHCP for an anyconnect client

jeyriku — Thu, 19 Jun 2008 07:08:26 GMT

Ok,

I do that for you and will keep you updated.

Many thanks for your help.

Regards,

Re: Ip address assignment via DHCP for an anyconnect client

jeyriku — Thu, 19 Jun 2008 07:47:21 GMT

Here is an attachment with the debug messages

Kind Regards,

Re: Ip address assignment via DHCP for an anyconnect client

Farrukh Haroon — Thu, 19 Jun 2008 08:50:02 GMT

The issue seems to be your DHCP server, check the DHCP server IP /scope once again. Also any logs on the DHCP server end.

7|Jun 19 2008 10:00:10|711001: Validating address: 0.0.0.0

7|Jun 19 2008 10:00:10|711001: CSTP state = WAIT_FOR_ADDRESS

7|Jun 19 2008 10:00:10|711001: webvpn_cstp_accept_address: 0.0.0.0/0.0.0.0

7|Jun 19 2008 10:00:10|711001: webvpn_cstp_accept_address: no address?!?

7|Jun 19 2008 10:00:10|711001: CSTP state = HAVE_AD

Regards

Farrukh

Re: Ip address assignment via DHCP for an anyconnect client

david.barroso — Thu, 17 Jul 2008 13:51:29 GMT

Who is the DHCP server? If the DHCP server is the firewall itself it's not possible. The DHCP server must be another server directly attached to the firewall.

Re: Ip address assignment via DHCP for an anyconnect client

jeyriku — Thu, 28 Aug 2008 08:07:57 GMT

Hi,

Many thanks for your answer and sorry for my delay.

In my configuration, The DHCP server is the FW itself. Do you konw why it can't Work?

Regards,

Re: Ip address assignment via DHCP for an anyconnect client

Farrukh Haroon — Thu, 28 Aug 2008 08:58:00 GMT

AFAIK this is a feature limitation.

Regards

Farrukh

Re: Ip address assignment via DHCP for an anyconnect client

jeyriku — Thu, 28 Aug 2008 10:50:30 GMT

Hi,

Do you mean by this that in theory it could be possible but this feature has not been implemented?

So what i did, i created a specific pool on my asa which has nothing to do with my LAN DHCP Range but i noticed that i could not assign a gateway to this pool. Can you confirm that i can't provide a gateway to this static pool. Imagine now that i begin to use this pool, how would i route the packet from this pool to my LAN scope or Internet, for example, without a default-route?

Regards,

Re: Ip address assignment via DHCP for an anyconnect client

Farrukh Haroon — Thu, 28 Aug 2008 12:28:07 GMT

Yes its 'possible' for sure but not implemented.

Makes no sense (to me) actually, if you need to give IP from the ASA, why use the 'DHCP' option, just make a POOL on the ASA! You can assign the other common DHCP pushed options like dns server, domain etc. from the VPN group-policy anyway.

Regards

Farrukh