DHCPv4/v6 Proxy

kchowdhury@starentnetworks.com

bsarikaya@huawei.com

IETF 67 DHC WG -- San Diego, USA 5-10 Nov. 2006

draft-sarikaya-dhc-proxyagent-00.txt

DHCP Proxy Overview• DHCP Proxy is a DHCP server but it does not do

the address management

• DHCPv4 Proxy• A mobile node joins the network, sends DHCPDISCOVER

• Proxy finds an address and replies with DHCPOFFER

• The MN sends DHCPREQUEST to get an address assigned

• DHCPv6 Proxy• MN may get an address using stateless address configuration• MN contacts DHCP Proxy possibly by sending Information Request• DHCP Proxy gets the information (locally or contacting other servers) and replies with Information-Reply• In the future DHCPv6 proxy may be used for IP address allocation.

Use Case-1persistent address assignment

BTS

GW+DHCP proxy

HA

AAA

DHCPPMIP

Core Network ProviderAccess Network Provider

HoA

Internet

HoA

MN

Use Case-2 parameter configuration

BTS

NAS+DHCP proxy

AAA

DHCP

Core Network ProviderAccess Network Provider

Internet

MN

Mobility Issue

BTS GW+DHCP proxy-2

HA

AAA

PMIP

Core Network Provider

Access Network Provider

HoAInternet

HoA

MN

GW+DHCP proxy-1

HO Direction

Mobility Issues

• MN moves to another subnet

• The DHCP client in the MS does not know about movement

• How should the MN re-sync with the new DHCP proxy?

• Which address the DHCP renew should be sent to?

• Relying on RENEW and REBIND timers (T1 and T2) may not suffice. The timers may be too long. The MS may send repeated RENEW messages over-the-air wasting radio resource

DHCP Extensions

• None yet.

Mailing List Discussions• Does the DHCP Proxy provide other parameters?

A: Yes

• Can LDAP server be used to store the parameters ?

A: Yes

• How to get an address by querying AAA server?

A: There is a draft on this? AAA servers are normally not used for address assignment.

• Who keeps the lease info?A: DHCP Proxy

Feedback Needed from DHC WG

• Should we assign a fixed address to DHCP Proxy?

 

.

• Issue a revision based on the comments

• What do you think about DHCP Proxy?

Next Steps

Thank You.Questions?