Ip-helper question

Jan Rockstedt · ‎03-16-2009

Hi all,

We have two ip-helper on our vlan 5.

It seems to take the first one every time and the DHCP scope are always full.

Any sugestion what we should do?

interface Vlan5

ip address 10.12.4.2 255.255.252.0

ip helper-address 10.12.1.41

ip helper-address 10.12.1.42

Regards Jan

Jon Marshall · ‎03-16-2009

Jan

The router/L3 switch uses both ip-helper's at the same time so it will forward a request to both DHCP servers. If you have split the scope for vlan 5 across both servers then it shouldn't matter if the first one has run out as the client will receive an offer from the second DHCP server.

Jon

Jan Rockstedt · ‎03-16-2009

Jon,

The

ip helper-address 10.12.1.41 = 10.12.6.1 - 254

ip helper-address 10.12.1.42 = 10.12.7.1 - 254

So it use both every time for request ip number... strange... why the 41 is full every time.

Jan

Jon Marshall · ‎03-16-2009

Jan

Usually the client will use the first DHCP offer it gets. Is there any difference between the servers in terms of

1) CPU usuage

2) Memory

3) Network utilisation on the NIC.

Perhaps the .41 server is just a faster server to respond.

Jon

Jan Rockstedt · ‎03-16-2009

There is, 41 is faster then 42.

Thanks Jan