Problem with ip helper

[crm114]

I have a 5412 running 15.08.0013 software.

i have 4 vlans. this is the core routing switch. i have configured ip helper on 3 vlans because the dhcp server is in the fourth vlan and doesn't need any help.

i have set the primary vlan to vlan 200, not left it at vlan 1.

when a user connects to a port in vlan 200 they get an ip address that belongs to vlan 201. If i disable the scope for vlan 201 they get an ip address for vlan 202. If i disable the 3 scopes, they get an address for vlan 200.

Could this be related to setting the primary vlan to 200?

thanks,

[Fredrik Lönnman]

Paste some relevant conf. What is a "primary vlan"?

[crm114]

primary vlan is a config that takes some of the function off the default vlan.

[paulgear]

The primary VLAN only affects which VLAN the switch itself gets DHCP on; it doesn't have anything to do with client DHCP. (See http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?lang=en&cc=us&objectID=c02099292&jumpid=reg_R1002_USEN for more details.)

Set "dhcp-relay option 82 replace ip" on your switch. (Unless it's already set and you removed it from the config; it would be better if you uploaded your entire switch config.)

[Fredrik Lönnman · Accepted solution]

also, what DHCP server are you running and how is it configured? I've seen some Windows DHCP servers configured with "supernet" that gave out IPs from wrong scopes when using ip-helper.

[crm114]

You were right, the scopes were all added under a super scopes option on the dhcp server.

thanks.