[67312] in North American Network Operators' Group
Re: Cisco: limit number of DHCP addresses per VC?
daemon@ATHENA.MIT.EDU (Jesper Skriver)
Sat Feb 7 17:54:08 2004
Date: Sat, 7 Feb 2004 23:53:26 +0100
From: Jesper Skriver <jesper@skriver.dk>
To: "Claydon, Tom" <Tom.Claydon@DobsonTelco.net>
Cc: "'nanog@merit.edu'" <nanog@merit.edu>
Mail-Followup-To: Jesper Skriver <jesper@skriver.dk>,
"Claydon, Tom" <Tom.Claydon@DobsonTelco.net>,
"'nanog@merit.edu'" <nanog@merit.edu>
In-Reply-To: <0E01363A875D25439211F10E850316C73C935D@entmail.dobsontelco.net>
Errors-To: owner-nanog-outgoing@merit.edu
On Wed, Feb 04, 2004 at 08:38:27AM -0600, Claydon, Tom wrote:
> Question for the list:
>
> Cisco introduced a command in 12.3T to limit DHCP leases on ATM unnumbered
> interfaces (ip dhcp limit lease per interface). This feature works fine on
> our 7206VXR, but my problem is that this is a global command. The Redback we
> were using before had us spoiled by allowing us to specify max DHCP leases
> per ATM VC! We would like to put other ATM VC's on this router that have
> different DHCP lease requirements.
>
> Is there any way of limiting DHCP leases per VC? Cisco TAC said they didn't
> have a non-global version of the ip dhcp limit lease per interface command.
>
> Our DHCP server is running dhcpd 2.0p15, BTW.
You can use the option 82 in the DHCP packet to do this on the DHCP
server, something like
# By default limit all customers to 1 DHCP lease
class "customer" {
spawn with option agent.remote-id;
lease limit 1;
}
subclass "customer" __OPTION_82_STRING_FOR_CUSTOMER__ {
lease limit 2;
}
__OPTION_82_STRING_FOR_CUSTOMER__ will be something like
01:01:00:00:01:02:03:04:40:02:01:20
^^^^^^^^^^^ ^^^^^^^^^^^ ^^ ^^ ^^^^^
fixed NAS IP addr | | VCI
| VPI
Port in this case 4/0
So this customer's pvc is 2/288 on ATM4/0 on the NAS with address
1.2.3.4
/Jesper
--
Jesper Skriver, jesper(at)skriver(dot)dk - CCIE #5456
One Unix to rule them all, One Resolver to find them,
One IP to bring them all and in the zone to bind them.
