Comments on Cisco IOS hints and tricks: Static DHCP assignment for clients without client-...

I wanted to be absolutely sure, so I started Wires...

2008-09-03T08:32:00.000+02:00

I wanted to be absolutely sure, so I started Wireshark and captured DHCP packets generated by Linux and Cisco IOS (or Windows XP). The results are here: by default Linux does not include Client identifier in DHCP packets, so Cisco IOS cannot match it with the pool configuration; you have to use mac-address.

instead of using hardware-address you can use clie...

2008-08-30T17:38:00.000+02:00

instead of using hardware-address you can use client-identifier in the DHCP pool options. To see what client-identifier your machines have do a show ip dhcp bind *, and you can use that parameter in the pool's configuration

@selcuk: this is what I've tried to do, but for wh...

2008-06-26T07:04:00.000+02:00

@selcuk: this is what I've tried to do, but for whatever reason, my dhclient.conf file worked while the machine was running but got ignored/overwritten (I don't remember which one any more) during the boot process. After a few hours, I gave up and found an IOS solution (after all, I'm a router-, not a Linux person :)

@anonymous: that's exactly what I'm doing, but if you see just the MAC address without the 01. prefix in the bindings, you don't know whether it's a host with broken Client-ID calculation (that happens as well) in which case you copy the value in client-id parameter, or a host not using the Client-ID at all forcing you to use hardware-address parameter.

My preffered way to solve this problem is define d...

2008-06-25T22:27:00.000+02:00

My preffered way to solve this problem is define dynamic DHCP pool then look into
show ip dhcp server bindings
to know how the client was recognized.

For most of the modern linux distributions, you ca...

2008-06-25T08:48:00.000+02:00

For most of the modern linux distributions, you can use /etc/dhcp3/dhclient.conf to send whatever client-id you want to the dhcp server. This way you do not have to change the configuration when you replace your server's or desktop's network card.

I added the following line to the conf file;
send dhcp-client-identifier 01:xx:xx:xx:xx:xx:xx (Replace xx with the mac address you want to use)