Re: DHCP server not responding to clients on other subnets

The DHCP server is authorized by the DC (it does distribute addresses to
clients sitting on its subnet).

When I do my tests I shutdown the other DHCP server (or I disconnect it from
the network, which, I guess, it is the same thing).

I apologize for the length of the post, I copied here below the Ethereal
output concerning the two frames DHCP inform and DHCP ack between a client
workstation and the server. It looks like the router (Cisco, IP address
157.150.88.1)) is actually propagating the DHCP request and the DHCP server
(IP address 157.150.91.56) seems getting it and replying, but then on the
client workstation I get the message "DHCP server unreachable".




No. Time Source Destination Protocol Info
46 19.240503 157.150.88.1 157.150.91.56 DHCP
DHCP Inform - Transaction ID 0xc46233ab

Frame 46 (342 bytes on wire, 342 bytes captured)
Ethernet II, Src: Cisco_c1:a0:c0 (00:14:1b:c1:a0:c0), Dst: Intel_9f:28:de
(00:04:23:9f:28:de)
Destination: Intel_9f:28:de (00:04:23:9f:28:de)
Address: Intel_9f:28:de (00:04:23:9f:28:de)
.... ...0 .... .... .... .... = Multicast: This is a UNICAST frame
.... ..0. .... .... .... .... = Locally Administrated Address: This
is a FACTORY DEFAULT address
Source: Cisco_c1:a0:c0 (00:14:1b:c1:a0:c0)
Address: Cisco_c1:a0:c0 (00:14:1b:c1:a0:c0)
.... ...0 .... .... .... .... = Multicast: This is a UNICAST frame
.... ..0. .... .... .... .... = Locally Administrated Address: This
is a FACTORY DEFAULT address
Type: IP (0x0800)
Internet Protocol, Src: 157.150.88.1 (157.150.88.1), Dst: 157.150.91.56
(157.150.91.56)
User Datagram Protocol, Src Port: bootps (67), Dst Port: bootps (67)
Bootstrap Protocol
Message type: Boot Request (1)
Hardware type: Ethernet
Hardware address length: 6
Hops: 1
Transaction ID: 0xc46233ab
Seconds elapsed: 0
Bootp flags: 0x0000 (Unicast)
0... .... .... .... = Broadcast flag: Unicast
.000 0000 0000 0000 = Reserved flags: 0x0000
Client IP address: 10.18.146.213 (10.18.146.213)
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: 157.150.88.1 (157.150.88.1)
Client MAC address: Intel_4d:8e:bb (00:11:11:4d:8e:bb)
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option 53: DHCP Message Type = DHCP Inform
Option 61: Client identifier
Hardware type: Ethernet
Client MAC address: Intel_4d:8e:bb (00:11:11:4d:8e:bb)
Option 12: Host Name = "UNC2447"
Option 60: Vendor class identifier = "MSFT 5.0"
Option 55: Parameter Request List
1 = Subnet Mask
15 = Domain Name
3 = Router
6 = Domain Name Server
44 = NetBIOS over TCP/IP Name Server
46 = NetBIOS over TCP/IP Node Type
47 = NetBIOS over TCP/IP Scope
31 = Perform Router Discover
33 = Static Route
249 = Classless static routes
43 = Vendor-Specific Information
252 = Proxy autodiscovery
End Option
Padding

No. Time Source Destination Protocol Info
47 19.240653 157.150.91.56 10.18.146.213 DHCP
DHCP ACK - Transaction ID 0xc46233ab

Frame 47 (348 bytes on wire, 348 bytes captured)
Ethernet II, Src: Intel_9f:28:de (00:04:23:9f:28:de), Dst: Cisco_c1:a0:c0
(00:14:1b:c1:a0:c0)
Destination: Cisco_c1:a0:c0 (00:14:1b:c1:a0:c0)
Address: Cisco_c1:a0:c0 (00:14:1b:c1:a0:c0)
.... ...0 .... .... .... .... = Multicast: This is a UNICAST frame
.... ..0. .... .... .... .... = Locally Administrated Address: This
is a FACTORY DEFAULT address
Source: Intel_9f:28:de (00:04:23:9f:28:de)
Address: Intel_9f:28:de (00:04:23:9f:28:de)
.... ...0 .... .... .... .... = Multicast: This is a UNICAST frame
.... ..0. .... .... .... .... = Locally Administrated Address: This
is a FACTORY DEFAULT address
Type: IP (0x0800)
Internet Protocol, Src: 157.150.91.56 (157.150.91.56), Dst: 10.18.146.213
(10.18.146.213)
User Datagram Protocol, Src Port: bootps (67), Dst Port: bootpc (68)
Bootstrap Protocol
Message type: Boot Reply (2)
Hardware type: Ethernet
Hardware address length: 6
Hops: 0
Transaction ID: 0xc46233ab
Seconds elapsed: 0
Bootp flags: 0x0000 (Unicast)
0... .... .... .... = Broadcast flag: Unicast
.000 0000 0000 0000 = Reserved flags: 0x0000
Client IP address: 10.18.146.213 (10.18.146.213)
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: 157.150.88.1 (157.150.88.1)
Client MAC address: Intel_4d:8e:bb (00:11:11:4d:8e:bb)
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option 53: DHCP Message Type = DHCP ACK
Option 54: Server Identifier = 157.150.91.56
Option 1: Subnet Mask = 255.255.254.0
Option 15: Domain Name = "unctad.unctad.org"
Option 3: Router = 10.18.146.1
Option 6: Domain Name Server
IP Address: 157.150.64.76
IP Address: 192.168.200.3
IP Address: 192.168.201.3
Option 44: NetBIOS over TCP/IP Name Server
IP Address: 157.150.64.77
IP Address: 157.150.64.203
End Option




"Phillip Windell" wrote:

You have to get rid of the old DHCP Server completely,...it cannot even be
powered up n the LAN,...or the Client will try to connect to it. Clients always
try the last DHCP they contacted and will always ask for the same IP Specs they
had "last time".

When you create Scopes, always use the entire full range of the subnet,...then
reduce it down to the addresses you wish to grant by using the Exclusions.

[Example]
Range: 10.18.146.1 --- 10.18.146.254
Exclusion #1 10.18.146.1 -- 10.18.146.99
Exclusion #2 10.18.146.201 -- 10.18.146.254
Options <whatever>

This will grant address to clients in the range of 10.18.146.100 --
10.18.146.200. If you run low on addresses and need more, then just shorten the
Exclusions.

Windows DHCP must be authorized by the DC before it can give out addresses.

--
Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com

The views expressed (as annoying as they are, and as stupid as they sound), are
my own and not those of my employer, or Microsoft, or anyone else associated
with me, including my cats.
-----------------------------------------------------
Understanding the ISA 2004 Access Rule Processing
http://www.isaserver.org/articles/ISA2004_AccessRules.html

Troubleshooting Client Authentication on Access Rules in ISA Server 2004
http://download.microsoft.com/download/9/1/8/918ed2d3-71d0-40ed-8e6d-fd6eeb6cfa07/ts_rules.doc

Microsoft Internet Security & Acceleration Server: Partners
http://www.microsoft.com/isaserver/partners/default.asp
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