Multilple leases with same client identifier
Christian Kratzer
ck-lists at cksoft.de
Wed Oct 24 20:25:41 UTC 2012
Hi,
we have a setup where we have customer cpe getting several leases for the specific vlans they are on for management, voip or internet access etc...
Most CPE we have tested either have a different ethernet hardware address on each vlan and/or they send a different uid for each of the vlans.
We have one specific device that sends identical ethernet addresses and uid for all the requests the different vlans.
When the device requests 3 leases one for each vlan it is on. The DHCP server releases the previously assigned leases as it assumes that the device has moved to a another network.
For n requests in n different vlans we get left with one valid and and n-1 released leases. We noticed when trying to query the leases by ip over omapi.
I have traced the releasing of the leases to find_lease() in dhcp.c
| if (uid_lease -> subnet -> shared_network != share) {
| #if defined (DEBUG_FIND_LEASE)
| log_info ("wrong network segment: %s",
| piaddr (uid_lease -> ip_addr));
| #endif
| goto n_uid;
| }
I have two questions:
1. Can I safely claim that the CPE is violating the specs by advertising equal identical uid for multiple concurrent leases.
2. Any ideas for a workaround until we get the cpe fixed ? Perhaps we could ignore the uid for the specific vendor ?
Greetings
Christian Kratzer
CK Software GmbH
--
Christian Kratzer CK Software GmbH
Email: ck at cksoft.de Wildberger Weg 24/2
Phone: +49 7032 893 997 - 0 D-71126 Gaeufelden
Fax: +49 7032 893 997 - 9 HRB 245288, Amtsgericht Stuttgart
Web: http://www.cksoft.de/ Geschaeftsfuehrer: Christian Kratzer
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