12-05-2008 06:17 AM - edited 03-06-2019 02:49 AM
Hi All,
I have a dhcp server on w2k3 and one scope for one LAN .
I want to have another scope on the same dhcp server for a 2nd Vlan and I did the IP helper and ip broadcast on the 2nd Vlan interface but it is not working.
No PC gets IP in the second scope.
Thaks,
Vlad
12-05-2008 06:23 AM
Please post your router config.
Thanks
Scott
12-05-2008 06:27 AM
Make sure that your vlan 2 SVI shows up and that the ports that the PCs are attached two are access ports of vlan 2. Otherwise, if this is the case, please do as Scott suggested and post the switch or router config.
HTH,
John
12-05-2008 06:40 AM
I ve done all these ...and routing is also enabled.
No idea tho' what s wrong
Thx,
Vlad
12-05-2008 06:34 AM
Scott ,
this is what I ve configured
This is a L3 Switch 4507.
interface Vlan7
ip address 172.20.19.1 255.255.255.0
no ip unreachables
no ip proxy-arp
load-interval 30
end
#sh run int vlan 60
Building configuration...
interface Vlan60
ip address 172.16.6.254 255.255.255.0
ip helper-address 172.51.19.254
ip directed-broadcast
end
The DHCP server is in Vlan 7 and has a scope for Vlan 60.
There is no ACL anywhere that could block any tcp or udp traffic.
Thanks,
Vlad
12-05-2008 06:35 AM
sorry the ip helper is 172.20.19.254 not as I copy pasted it.
12-05-2008 06:36 AM
Make sure you have ip routing enabled. Can you ping VLAN 60 from a system in Vlan 7, like the DHCP server?
Oh, and is your scope enabled on the server?
HTH,
John
12-05-2008 06:43 AM
I can ping the SVI in 60 from the DHCP in 7 and scope is also active.
thx
Vlad
12-05-2008 07:59 AM
Vlad
Can you post
"sh ip int brief"
"sh ip route"
sh int ?? where ?? is the interface that you have a PC plugged into on vlan 60.
Jon
12-05-2008 09:12 AM
Jon,
I assume this is what u are interested in:
172.16.0.0/16 is variably subnetted
172.16.6.0/24 is directly connected, Vlan60
Vlan60 172.16.6.254 YES manual up up
interface GigabitEthernet3/6
switchport access vlan 60
switchport mode access
switchport nonegotiate
load-interval 30
no snmp trap link-status
spanning-tree portfast
Thanks,
Vlad
12-05-2008 09:18 AM
Hello vlad
not sure why you need "ip directed broadcast" on vlan 60 interface ! ip helper actually converts your dhcp broadcasts to a unicast message.. in any case, run a sniffer on the PC, and see what happens.. See if you get any updates back from the dhcp server.. do you see any error logs on the server ? make sure you specify a dhcp exclude address for 172.16.6.254 , which is the vlan 60 SVI interface !
Raj
12-08-2008 05:06 AM
Hello Raj,
I know the ip-helper converts the broadcast to unicast , but I could not get it to work so I tried.
Anyway , if I hardcode an IP address on a PC in that Vlan I can ping the DHCP and viceversa.
I will wireshark it and let you know.
Thanks,
Vlad
12-05-2008 09:20 AM
Vlad
If you take a PC in the subnet that is not getting addresses from the DHCP server and you hard code an IP address of that subnet on the PC, can the PC then ping the DHCP server?
HTH
Rick
12-08-2008 05:40 AM
Rick,
The server and the PC can ping one another.
I have wireshark it and I see the request from the PC but no arp from the DHCp server.
Anyway,
I dont know if I mentioned it , but on the same server I have another DHCP scope in vlan 7.
Thx,
Vlad
12-08-2008 06:23 AM
Vlad,
Same configuration made it in my lab its working fine . check changes what i made in configuration.
interface Vlan7
ip address 172.20.19.1 255.255.255.0
end
interface Vlan60
ip address 172.16.6.254 255.255.255.0
ip helper-address 172.20.19.254
no ip directed-broadcast
end
interface GigabitEthernet3/6
switchport access vlan 60
switchport mode access
sw host
Regards
Ram
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