ProCurve 2848 dhcp-relay not working

[brakerm19]

It seems like my switch is not relaying the DHCP offer packet back to the original client therefore the client does not acquire the assigned/offered address.

Clients connected to ports on the same VLAN as the DHCP server work properly.

Can anyone help?

==============================================
Setup:
++++++++++
Windows 2003 DHCP Server (Guest OS on ESX3.5 Host)
IP - 172.20.1.10/24 (VLAN10)
Connected via Port 43 on HP Switch
HP ProCurve 2848 Switch (I_10_77.swi)
IP - 172.20.1.254 (VLAN10)
IP - 172.20.100.1 (VLAN100)
VLAN100CLIENT: WinXP SP3
Trying to acquire DHCP (VLAN100)
Connected via Port 10
DefaultGateway/Firewall/Internet Router:
IP - 172.10.1.1 (VLAN10)
Connected via port 41 ============================================
C O N F I G
++++++++++++
Switch Config:
; J4904A Configuration Editor; Created on release #I.10.77

hostname "HP2848-a71111"
time timezone -300
time daylight-time-rule Continental-US-and-Canada
no web-management
web-management ssl
interface 39
disable
exit
sntp server 172.20.1.10
ip routing
timesync sntp
sntp unicast
snmp-server community "public" Operator
vlan 1
name "DEFAULT_VLAN"
untagged 1,45-48
ip address dhcp-bootp
no untagged 2-44
exit
vlan 100
name "DataVLAN"
untagged 2-16
ip address 172.20.100.1 255.255.255.0
ip helper-address 172.20.1.10
exit
vlan 10
name "ServerVLAN"
untagged 17-44
ip address dhcp-bootp
ip helper-address 172.20.1.10
exit
dhcp-snooping
dhcp-snooping authorized-server 172.20.1.10
dhcp-snooping vlan 10 100
interface 43
dhcp-snooping trust
exit
ip ssh
password manager
password operator



=============================================
D E B U G
++++++++++
Switch DHCP Debug to session:
DSNP DHCP DISCOVER: port 10, vid 100, from 000BDB-C2C503 requested:
169.254.61.153, udp forwarder also handling packet.
DSNP DHCP OFFER: port 43, vid 10, from 005056-812222 to 001818-FF4444 from
server-id: 172.20.1.10 offered: 172.20.100.2 lease time 3600 seconds, allow:
output port 41.
DSNP DHCP DISCOVER: port 10, vid 100, from 000BDB-C23333 requested:
169.254.61.153, allow: broadcast on untrusted input port to trusted output
ports.
DSNP DHCP DISCOVER: port 10, vid 100, from 000BDB-C23333 requested:
169.254.61.153, udp forwarder also handling packet.
DSNP DHCP OFFER: port 43, vid 10, from 005056-812222 to 001818-FF4444 from
server-id: 172.20.1.10 offered: 172.20.100.2 lease time 3600 seconds, allow:
output port 41.


==============================================
DHCP Server Wireshark:
++++++++++++++++++++++++
No. Time Source Destination Protocol Info
1 0.000000 172.20.100.1 172.20.1.10 DHCP DHCP Discover - Transaction ID 0x9bc005b4

Frame 1 (356 bytes on wire, 356 bytes captured)
Ethernet II, Src: HewlettP_a7:11:11 (00:11:0a:a7:11:11), Dst: Vmware_81:22:22 (00:50:56:81:22:22)
Internet Protocol, Src: 172.20.100.1 (172.20.100.1), Dst: 172.20.1.10 (172.20.1.10)
User Datagram Protocol, Src Port: bootpc (68), Dst Port: bootps (67)
Bootstrap Protocol
Message type: Boot Request (1)
Hardware type: Ethernet
Hardware address length: 6
Hops: 1
Transaction ID: 0x9bc005b4
Seconds elapsed: 5
Bootp flags: 0x0000 (Unicast)
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 0.0.0.0 (0.0.0.0)
Relay agent IP address: 172.20.100.1 (172.20.100.1)
Client MAC address: DellEsgP_c2:33:33 (00:0b:db:c2:33:33)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option: (t=53,l=1) DHCP Message Type = DHCP Discover
Option: (t=116,l=1) DHCP Auto-Configuration [TODO]
Option: (t=61,l=7) Client identifier
Option: (t=50,l=4) Requested IP Address = 169.254.61.153
Option: (t=12,l=9) Host Name = "VLAN100CLIENT"
Option: (t=60,l=8) Vendor class identifier = "MSFT 5.0"
Option: (t=55,l=11) Parameter Request List
Option: (t=43,l=2) Vendor-Specific Information
Option: (t=82,l=12) Agent Information Option
End Option

No. Time Source Destination Protocol Info
2 0.001597 172.20.1.10 172.20.100.1 DHCP DHCP Offer - Transaction ID 0x9bc005b4

Frame 2 (342 bytes on wire, 342 bytes captured)
Ethernet II, Src: Vmware_81:22:22 (00:50:56:81:22:22), Dst: Cisco_ff:44:44 (00:18:18:ff:44:44)
Internet Protocol, Src: 172.20.1.10 (172.20.1.10), Dst: 172.20.100.1 (172.20.100.1)
User Datagram Protocol, Src Port: bootps (67), Dst Port: bootps (67)
Bootstrap Protocol
Message type: Boot Reply (2)
Hardware type: Ethernet
Hardware address length: 6
Hops: 0
Transaction ID: 0x9bc005b4
Seconds elapsed: 0
Bootp flags: 0x0000 (Unicast)
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 172.20.100.2 (172.20.100.2)
Next server IP address: 172.20.1.10 (172.20.1.10)
Relay agent IP address: 172.20.100.1 (172.20.100.1)
Client MAC address: DellEsgP_c2:33:33 (00:0b:db:c2:33:33)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option: (t=53,l=1) DHCP Message Type = DHCP Offer
Option: (t=1,l=4) Subnet Mask = 255.255.255.0
Option: (t=58,l=4) Renewal Time Value = 30 minutes
Option: (t=59,l=4) Rebinding Time Value = 52 minutes, 30 seconds
Option: (t=51,l=4) IP Address Lease Time = 1 hour
Option: (t=54,l=4) DHCP Server Identifier = 172.20.1.10
Option: (t=3,l=4) Router = 172.20.100.1
Option: (t=6,l=4) Domain Name Server = 172.20.1.10
Option: (t=44,l=4) NetBIOS over TCP/IP Name Server = 172.20.1.10
Option: (t=46,l=1) NetBIOS over TCP/IP Node Type = H-node
End Option
Padding

No. Time Source Destination Protocol Info
3 6.992187 172.20.100.1 172.20.1.10 DHCP DHCP Discover - Transaction ID 0x9bc005b4

Frame 3 (356 bytes on wire, 356 bytes captured)
Ethernet II, Src: HewlettP_a7:11:11 (00:11:0a:a7:11:11), Dst: Vmware_81:22:22 (00:50:56:81:22:22)
Internet Protocol, Src: 172.20.100.1 (172.20.100.1), Dst: 172.20.1.10 (172.20.1.10)
User Datagram Protocol, Src Port: bootpc (68), Dst Port: bootps (67)
Bootstrap Protocol
Message type: Boot Request (1)
Hardware type: Ethernet
Hardware address length: 6
Hops: 1
Transaction ID: 0x9bc005b4
Seconds elapsed: 12
Bootp flags: 0x0000 (Unicast)
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 0.0.0.0 (0.0.0.0)
Relay agent IP address: 172.20.100.1 (172.20.100.1)
Client MAC address: DellEsgP_c2:33:33 (00:0b:db:c2:33:33)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option: (t=53,l=1) DHCP Message Type = DHCP Discover
Option: (t=116,l=1) DHCP Auto-Configuration [TODO]
Option: (t=61,l=7) Client identifier
Option: (t=50,l=4) Requested IP Address = 169.254.61.153
Option: (t=12,l=9) Host Name = "VLAN100CLIENT"
Option: (t=60,l=8) Vendor class identifier = "MSFT 5.0"
Option: (t=55,l=11) Parameter Request List
Option: (t=43,l=2) Vendor-Specific Information
Option: (t=82,l=12) Agent Information Option
End Option

No. Time Source Destination Protocol Info
4 6.994812 172.20.1.10 172.20.100.1 DHCP DHCP Offer - Transaction ID 0x9bc005b4

Frame 4 (342 bytes on wire, 342 bytes captured)
Ethernet II, Src: Vmware_81:22:22 (00:50:56:81:22:22), Dst: Cisco_ff:44:44 (00:18:18:ff:44:44)
Internet Protocol, Src: 172.20.1.10 (172.20.1.10), Dst: 172.20.100.1 (172.20.100.1)
User Datagram Protocol, Src Port: bootps (67), Dst Port: bootps (67)
Bootstrap Protocol
Message type: Boot Reply (2)
Hardware type: Ethernet
Hardware address length: 6
Hops: 0
Transaction ID: 0x9bc005b4
Seconds elapsed: 0
Bootp flags: 0x0000 (Unicast)
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 172.20.100.2 (172.20.100.2)
Next server IP address: 172.20.1.10 (172.20.1.10)
Relay agent IP address: 172.20.100.1 (172.20.100.1)
Client MAC address: DellEsgP_c2:33:33 (00:0b:db:c2:33:33)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option: (t=53,l=1) DHCP Message Type = DHCP Offer
Option: (t=1,l=4) Subnet Mask = 255.255.255.0
Option: (t=58,l=4) Renewal Time Value = 30 minutes
Option: (t=59,l=4) Rebinding Time Value = 52 minutes, 30 seconds
Option: (t=51,l=4) IP Address Lease Time = 1 hour
Option: (t=54,l=4) DHCP Server Identifier = 172.20.1.10
Option: (t=3,l=4) Router = 172.20.100.1
Option: (t=6,l=4) Domain Name Server = 172.20.1.10
Option: (t=44,l=4) NetBIOS over TCP/IP Name Server = 172.20.1.10
Option: (t=46,l=1) NetBIOS over TCP/IP Node Type = H-node
End Option
Padding
==============================================

[Shadow13]

Remove teh DHCP snooping then try again just to isolate the issue.

[Josh Boyer]

Hello brakerm19,

I dont see DHCP-Relay enabled in your switch configuration. Can you confirm that his is enabled as it is required for DHCP-Relay to function.

http://ftp.hp.com/pub/networking/software/AdvTraff-Oct2005-59908853-Chap07-IProuting.pdf

page 25

"Minimum Requirements for DHCP Relay Operation
In order for the DHCP Relay agent to work, the following steps must be
completed:
1. DHCP Relay is enabled on the routing switch
2. A DHCP server is servicing the routing switch
3. IP Routing is enabled on the routing switch
4. There is a route from the DHCP server to the routing switch and back
5. An IP Helper address is configured on the routing switch, set to the IP
address of the DHCP server on the VLAN that is connected to the DHCP
Client.
Enabling DHCP Relay
To enable the DHCP Relay function for the routing switch, at the Config CLI
context level, enter the command:
ProCurve(config)# dhcp-relay"

Regards,

[brakerm19]

I found my issue.

My default gateway for my DHCP server was set to 172.20.1.1 (internet firewall router) and not 172.20.1.254 (VLAN 10 IP Management address on the Switch)

This is why it seems the DHCP was forwarding the offer to the wrong MAC address.

On the ProCurve 2848 DHCP-Relay is on by default.

Thanks for the input.

[Josh Boyer]

Hi Brakerm,

Glad you found your issue.

Sorry my information was not accurate however HP did not mention in there documentation that DHCP-Relay was enabled and not visable in the show run on this switch.

The documentation I quoted was for 2600/2800/4100 series switches.

Did you see this in any documentation you read? How did you determine it was on by default? Just woundering so I can ensure I don't make the same suggestion in the future for a switch that has this enabled by default.

Regards,