Linux Distributed Switch Architecture with Local Option82 ISC DHCP server/DHCP relay
glenn.satchell at uniq.com.au
glenn.satchell at uniq.com.au
Mon Nov 23 21:48:49 UTC 2020
Hi Remi
So it looks like the circuit-id is not matching. Can you do a packet
trace and verify the exact content of the circuit-id values? Perhaps
there is a trailing non-print character? Is it possible the initial
packet is getting through - the one without the added circuit-id?
I can see the customer's hardware limitations, but it seems to me a
different switch with inbuilt dhcp-relay would make this a very simple
solution. :(
regards,
Glenn
On 2020-11-23 22:31, remi rsd wrote:
> Hello Simon. Thanks for your messages.
> Some news from the field.
>
>
> Option82 was effectively "sold" to the customer. Mandatory.
> Switch cannot be replaced by another one.
> For the moment, I would like to avoid any monitoring daemon.
>
>
> I applied your recommendation about declaring shared-network (and
> hacked a
> bit dhcrelay for debugging purpose):
> effectively, now DHCPd receive relayed packets with circuit-id
>
>
> I found also this http://www.miquels.cistron.nl/isc-dhcpd/
> Added the patch patch in order to log circuit-id info.
>
> Then I updated my config:
>
>
> first try:
>
> stash-agent-options true;
>
> log-facility local7;
>
> if exists agent.circuit-id
> {
> log (info, concat("Lease for ", option agent.circuit-id));
> }
>
> host port1 {
> host-identifier option agent.circuit-id "port1";
> fixed-address 192.168.1.31;
> }
>
> host port2 {
> host-identifier option agent.circuit-id "port2";
> fixed-address 192.168.1.32;
> }
>
> host port3 {
> host-identifier option agent.circuit-id "port3";
> fixed-address 192.168.1.33;
> }
>
> host port4 {
> host-identifier option agent.circuit-id "port4";
> fixed-address 192.168.1.34;
> }
>
> shared-network my_bridge {
> subnet 172.20.31.0 netmask 255.255.255.0 {}
> subnet 172.20.32.0 netmask 255.255.255.0 {}
> subnet 172.20.33.0 netmask 255.255.255.0 {}
> subnet 172.20.34.0 netmask 255.255.255.0 {}
>
> subnet 192.168.1.0 netmask 255.255.255.0 {
> option routers 192.168.1.20;
> option broadcast-address 192.168.1.255;
> option domain-name-servers 192.168.1.20;
> option domain-name "bus-1";
> }
> }
>
> Result:
> "DHCPDISCOVER from 28:d2:44:50:a5:05 via dsa_br0: network my_bridge: no
> free
> leases"
>
> => No lease
>
> If I add a default pool, lease provided and a log for circuit-id is
> displayed, confirming that DHCPd received packet from relay agent
>
>
> I tried another way:
>
> shared-network my_bridge {
> subnet 172.20.31.0 netmask 255.255.255.0 {}
> subnet 172.20.32.0 netmask 255.255.255.0 {}
> subnet 172.20.33.0 netmask 255.255.255.0 {}
> subnet 172.20.34.0 netmask 255.255.255.0 {}
>
> subnet 192.168.1.0 netmask 255.255.255.0 {
> option routers 192.168.1.20;
> option broadcast-address 192.168.1.255;
> option domain-name-servers 192.168.1.20;
> option domain-name "bus-1";
>
>
> class "port1" {
> match if option agent.circuit-id = "port1";
> }
> pool {
> allow members of "port1";
> range 192.168.1.31;
> }
>
> class "port2" {
> match if option agent.circuit-id = "port2";
> }
> pool {
> allow members of "port2";
> range 192.168.1.32;
> }
>
> class "port3" {
> match if option agent.circuit-id = "port3";
> }
> pool {
> allow members of "port3";
> range 192.168.1.33;
> }
>
> class "port4" {
> match if option agent.circuit-id = "port4";
> }
> pool {
> allow members of "port4";
> range 192.168.1.34;
> }
> }
> }
>
> Result:
> "DHCPDISCOVER from 28:d2:44:50:a5:05 via dsa_br0: network my_bridge: no
> free
> leases"
>
> => same result, no lease.
>
>
> The difference with the example un in the link above is the HW address.
> Is it really necessary to declare HW address of device ? Circut-id
> match is
> not enough ?
>
>
>
>
>
>
> --
> Sent from: http://isc-dhcp-users.2343191.n4.nabble.com/
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