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DHCP and ambiguous VLANS

Hi,

I have an ASR9001 running 5.1.3.  is it possible to configure an interface using "encapsulation ambiguous dot1q any second any" , and have DHCP requests forwarded to a DHCP server.

I have a need where I have a large number of DHCP clients that do not need to be authenticated/accounted etc, but are delivered on random QinQ combinations.  I would like to treat these clients as straight dhcp clients vs. BNG (i.e. licensed) clients.

 

I have configured up 

dhcp ipv4

profile VOICE proxy
  class DHCP-loopback203
   helper-address vrf voice 10.10.10.1 giaddr 10.203.0.1
   helper-address vrf voice 10.10.10.2 giaddr 10.203.0.1

interface Bundle-Ether203.1 proxy profile VOICE

 

interface Bundle-Ether203.1
 vrf voice
 ipv4 point-to-point
 ipv4 unnumbered Loopback203
 encapsulation ambiguous dot1q any second-dot1q any

 

I can see the DHCP request coming in, however the debug dhcp proxy says that the discovery packets are being dropped.

 

RP/0/RSP0/CPU0:Oct 30 11:41:19.893 : dhcpd[1082]: DHCPD PROXY: TP1955: FSM called for chaddr d054.2d69.d16f with event PACKET_DISCOVER state INIT
RP/0/RSP0/CPU0:Oct 30 11:41:19.893 : dhcpd[1082]: DHCPD PROXY: TP1903: Process packet event in INIT state called for chaddr d054.2d69.d16f
RP/0/RSP0/CPU0:Oct 30 11:41:19.894 : dhcpd[1082]: DHCPD PROXY: TP1955: FSM called for chaddr d054.2d69.d16f with event DPM_SUCCESS state INIT_DPM_WAIT
RP/0/RSP0/CPU0:Oct 30 11:41:19.894 : dhcpd[1082]: DHCPD PROXY: TP1665: Proxy process client request packet failed for chaddr d054.2d69.d16f
RP/0/RSP0/CPU0:Oct 30 11:41:19.894 : dhcpd[1082]: DHCPD PROXY: TP2739: Dropping DISCOVER for d054.2d69.d16f received on ambiguous VLAN interface for standalone proxy

 

Any help would be appreciated.  If i have to use a BNG license for each of these clients, my 32K sessions will be effectively halved..

 

many thanks

 

1 REPLY
Cisco Employee

hi mike,yeah you need a BNG

hi mike,

yeah you need a BNG configuration also in order to use the amb vlans for dhcp proxy.

the bng piece of it keeps track of the vlan combo and helps dhcp to provide the proper

encapsulation when the dhcp messages are sent back and forth.

For that, you'll need the bng pie, and subscriber control policy configuration and bng is indeed a licensed feature...

regards

xander

Xander Thuijs CCIE #6775 Principal Engineer ASR9000, CRS, NCS6000 & IOS-XR
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