Configuring dhcp on controllers

[Rosa Ladeira]

Network environment:

2 AIR-WLC2106-K9

2 AIR-WLC2112-K9

7 AIR-CAP35202-I-A-K9

10 AIR-LAP1131AG-A-K9

9 AIR-LAP1252-AG-T-K9

Cisco6509-E

If controllers and APs have fixed IPs manually set, is it necessary to inform:

1. Primary and secondary DHCP Server IP on interface configuration ?

2. Conreoller Internal DHCP Scope and Leases?

3. WLAN advanced DHCP options (override, dhcp ip address)?

Thanks

Rosa

[Sebastian Helmer]

no nothing of all three when u have everything manually configured...

[Rosa Ladeira]

Thanks.

Is there any controller dhcp configutaion for clients (notebooks, smartphones) ?

[Scott Fella]

For your dynamic interfaces for clients, it's probably best practice to add your primary and secondary DHCP servers. Now with DSCP proxy enabled, the WLC will proxy the DSCP broadcast to those servers.  If you disable DSCP proxy, then you will need ip helpers on your svi to forward the DHCP request.  DHCP proxy might now work if a firewall is the DHCP server since they dont want to see DHCP request proxied.

-Scott

[Rosa Ladera]

Thanks Scott.

Since DSCP is equal zero on Mobility anchor config, it means dscp proxy is disable ?

There is no QOS configured?

Should I configure :

ip forward-protocol udp 5246

and

ip helper-address DHCP-IP-SERVER

on 6509 ports where controllers and APs are connected ?

By now, a Linux DHCP external server is offering IPs to clients:

class "Cisco AP c3500" {
        match if option vendor-class-identifier = "Cisco AP c3500";
        option vendor-class-identifier "Cisco AP c3500";
        vendor-option-space CiscoAPs;
        option CiscoAPs.server-address DHCP-IP-SERVER;
    }

should DHCP-IP-SERVER be specified as 4 decimal numbers ou f104xxyyzzaa notation ?

Thanks

[Rosa Ladera]

Scott I have a few questions based on the fact that controllers ports are connected to NX7000 interfaces.

1. I have understood that it would be desirable to configure ip forward-protocol udp 5246 and ip helper-address DHCP-IP-SERVER on interfaces where ap-manager controller port has been connected.

2. NX-OS offers ip dhcp snooping set. Have those commands the same effect ?

3. when clients (mobiles and hosts) look for a DHCP IP address it will be sufficient for avoidding brodcast floods configure snooping on its vlan?

[Rosa Ladera]

How can I avoid brodcast floods from clients (mobiles and hosts) looking  for a DHCP IP address ?

It would be sufficient configure ip dhcp snooping on clients vlan?