DHCP Configuration Trouble

[wrong12]

I have a 2600 Router, that accept the command
ip forward-protocol udp bootpc, but does not
accept (does not show in the configuration) the
command ip forward-protocol udp bootps; therebefore
my DHCP configuration doesn't work.

what can i check or how i can fic this situación

 

[burtsbees]

I believe with the ip helper-address command.

Burt

 

[ADB100]

As Burt says you need to add the 'ip helper-address x.x.x.x' command on the interfaces where the DHCP clients are (x.x.x.x should be the DHCP server).

By default as soon as you configure IP helpers there are 9 UDP broadcast types that are forwarded to the helper, Leaving them all enabled can cause issues so once you have configured your IP helper(s) I recommend disabling the non-DHCP/BOOTP protocols:

no ip forward-protocol udp tftp
no ip forward-protocol udp nameserver
no ip forward-protocol udp domain
no ip forward-protocol udp time
no ip forward-protocol udp netbios-ns
no ip forward-protocol udp netbios-dgm
no ip forward-protocol udp tacacs

HTH

Andy

 

[wrong12]

Thanks Burt/Andy.

I'm wasn´t specific when explained the situación. My router have in each logic interface the ip helper command.
In fact, I working with six Vlan's and i have six ip helper command (twice, beacuse I have 2 dhcp server).
The problem is with the ip forward-protocol udp bootps command. When I submit this command, the router just accept, but it doesn't in its configuration. Do you think that this action is product by the corrupt IOS?

 

[burtsbees]

Are you saying that the command simply does not show up when you do a "sh run"? Or are you saying that it appears the router accepts the command, but it does not forward the bootp requests through the router?

Burt

 

[wrong12]

Is correct Burt, the router accepts the command but I suppose that it does not foward the bootp request. For aditional information, the router does not show the command in the sh run execution.

 

[ADB100]

Is correct Burt, the router accepts the command but I suppose that it does not foward the bootp request. For aditional information, the router does not show the command in the sh run execution.

The reason it doesn't appear in the configuration is it is there by default, it would only appear if you disabled it and then it would be preceded by 'no' indicationg it was disabled. Read what I posted in my previous post.

Andy

 

[voltron1011]

Yes, there's a lot of commands on routers and switches that won't show up in the config lines. This is usually the commands that are 'on' by default.

 

[burtsbees]

Yes---I was asking what indication you are getting that the router is not forwarding bootp requests?

Burt

 

[plshlpme]

do you have
"service dhcp "

in your config?

 

[wrong12]

Hi,

I need some help with this topic. In my office we have a sofware for printer monitoring across network. But I have my network seperated by VLANS, therefore I only can monotoring the printers that are in the same vlans. How could I do for access all the printers in the entire networks? I try with a trunk ports, but it does not work.

 

[plshlpme]

your pc would have to be allowed to talk to all vlans.. are some of your vlans not being routed? or is this pc denied access to some of them?