DHCP snooping and ip helper interaction

From: Geert Nijs (Geert.Nijs@simac.be)
Date: Sat Mar 22 2008 - 12:32:47 ART


All,

Does a DHCP snooping configuration NEED an ip helper address defined on the
same switch ?

In my lab setup, DHCP breaks when i configure dhcp snooping without ip helper
address.
Setup:

Access = C3750 , 12.2(25)SE2
Distribution= C6500, sup720, 12.2(18)SXF8

ACCESS
int vlan 100
 ip address 1.1.1.250 255.255.255.0 <- for management of the
switch !

int gi1/0/49 <--- uplink (is dhcp trusted)
 ip dhcp trust

ip dhcp snooping vlan 100 <- activate snooping
on access

DISTRIBUTION
int vlan 100
 ip address 1.1.1.2 255.255.255.0
 standby 1 ip 1.1.1.1
 ip helper-address 192.168.1.1

Without dhcp snooping on the access, the config works. Clients get an ip
address.
Once i enable dhcp snooping on the access, dhcp doesn't work anymore ??

regards,
Geert Nijs

  ________________________________
disclaimer : http://webservices.simac.be/disclaimer.htm



This archive was generated by hypermail 2.1.4 : Tue Apr 01 2008 - 07:53:54 ART