2930F DHCP with several address pools?

[staffanu]

We're currently using a linux server to run isc dhcpd but want to migrate to use one of our 2930F switches in order to retire some hardware. The dhcp server should allocate addresses in any of three networks. There is no difference between the networks so any client is happy with any address in one of them. For isc dhcpd, the config file has one "shared-network" section containing three "subnet" declarations.

When trying this on the 2930F, I set up three pools since I could not figure out a way to assign more than one subnet or address range to a single pool. The switch has an address on each of the subnets. However, only one pool is used for addresses, so when deploying this configuration we quickly run out of addresses.

Does anyone understand what's going on? Is this not supported or did I misunderstand someting? The relevant part of the config file at the end of the post.

Thanks,

Staffan

dhcp-server pool "MYNET25"
authoritative
default-router "x.x.25.129"
dns-server "x.x.27.200,x.x.27.201"
domain-name "mynet.org"
lease 00:00:15
network x.x.25.128 255.255.255.128
range x.x.25.132 x.x.25.254
exit
dhcp-server pool "MYNET26"
authoritative
default-router "x.x.26.129"
dns-server "x.x.27.200,x.x.27.201"
domain-name "mynet.org"
lease 00:00:15
network x.x.26.128 255.255.255.128
range x.x.26.132 x.x.26.254
exit
dhcp-server pool "MYNET27"
authoritative
default-router "x.x.27.254"
dns-server "x.x.27.200,x.x.27.201"
domain-name "mynet.org"
lease 00:00:15
network x.x.27.0 255.255.255.0
range x.x.27.1 x.x.27.199
exit
vlan 1
dhcp-server
ip address x.x.27.203 255.255.255.0
ip address x.x.25.131 255.255.255.128
ip address x.x.26.131 255.255.255.128
exit
dhcp-server conflict-logging
dhcp-server enable

[akg7]

Hello,

Multiple pools is possible but why vlan1 has multiple IP assignments?

 A vlan can have only one subnet of IP address.

Thanks!

[staffanu]

So exactly what do you mean when you say that a vlan can have only one subnet? In general this is certainly possible, so I assume you mean that the switch is only capable of serving dhcp addresses for one subnet per vlan?

If this is the case a workaround would be to have three different vlans for the dhcp service, and to untag the vlans again by using two switch ports, but that really seems like an ugly workaround...

Staffan