Joined: 09 Jul 2006 Posts: 71 Location: Nanaimo BC Canada
Posted: Tue Jul 25, 2006 13:19 Post subject: Use NVRAM for client lease DB
Under Services, DHCP server...you can check off Use NVRAM for client lease DB...what is the purpose of this setting...other than the obvious....where would the DB be located if you did not check this off...or would there be no DB created at all?
Joined: 07 Jun 2006 Posts: 1488 Location: the Netherlands
Posted: Tue Jul 25, 2006 13:26 Post subject:
Sounds to me it saves the db on nvram (duh) which would save your leases even when the router is rebooted or loses power. _________________ Firmware: DD-WRT v24-sp2 (latest available) mega
WRT320N
Doesn't seem to be working in the 07/24 release of V23 SP2 anyway. I noticed that nvram now contains "static_leases" and the server is no longer looking at /tmp/dnsmasq.conf. When I tried to change it back to the former mode it just throws an error on saving the Services.asp page. This has apparently been corrected, so I'll try again after today's build becomes available.
Joined: 09 Jul 2006 Posts: 71 Location: Nanaimo BC Canada
Posted: Tue Jul 25, 2006 19:16 Post subject:
Thanx lawnmowerguy1 and rickross,
It seems the 07/24 release does not report clients for me...release renew doesnt have any affect on the router report...maybe rebooting a client may. I cant enable SSHd either...just get an "error on page" that refers to 'dhcpd_usenvram' is null or not an object when I check off SSHd and hit Save...strange...but it is Beta so I cant complain....
I'm using the 5/16/06 build of SP1. Under DHCP Server, I have the option to check "Use JFFS2 for client lease DB". It is currently disabled. With that in mind, where are my leases stored now? On the NVRAM? They seem to be plenty stable and survive resets, etc, but is there a better place to store them? Should I enable storage on JFFS2? Move them to my Samba share? If so, how would I go about moving them there? Or should I leave well enough alone? I'll be migrating to SP2 here shortly, so will that offer different options? This is a bit confusing. Any help is appreciated. Thanks.
this hasn't been fixed has it? i downloaded the 7-24 release and still see the problem. it's marked as "fixed" in the bugtracker.
i can set the dhcpd_usenvram=1 as suggested above... but i need to do more than just that (ie enter my MAC, hostname, IP for dhcpd, turn on ssh, etc...
I am just curious, what is the benefit to using the "Use NVRAM for client lease DB" option? Turning it off frees up a large chunk of memory. OK, so with this option turned off, the lease database is lost on reboot. What is the benefit for storing the lease database so the client does not have to renew its IP when the router reboots?
I am just curious, what is the benefit to using the "Use NVRAM for client lease DB" option?
Hummm, how interesting that there are members of this forum that use this option, but have no idea why they are using this option. OK. so after a few days of evaluatiing whether or not to use this option, I will reply to my own post:
What is the benefit of storing the lease database in nvram? There is no benefit. When the router reboots the lease database is lost. Big deal! So the client has to renew its lease with the DHCP server and may be issued a different IP address. Big deal! The benefit in NOT enabling this option? You save a large chunk of memory.
Perhaps there is a benefit to storing the Client Lease Data Base in the NVRAM, or JFFS (the other option) if you have static IP leases. Anyone played around with that? If the DB isn't stored, do the static leases get reassigned after reboot? We'll have to see! _________________ Clear 4G Wimax.
Linksys WRT54G-TM w/14929 std-nokaid, fan-cooled, 2 GB SD mod, Primary Router.
Linksys WRT54G v.3 w/15230 std-nokaid, Client Bridge.
Linksys E2000 w/15200 "Big"
Linksys WRT54G v.4
La Fonera 2100, fan-cooled
Linksys WRT54G v.3.1
Linksys WRT54G v.1.1
Linksys WRT54GS v.1
2x Linksys WRT54G v.2.2
Ahh, I finally see the light. I guess the only reason why anyone would need to enable this option is for static address allocation, otherwise it is a waste of memory if all you have is dynamic clients.
this feature is useless for small home-lan´s and i can explan you why.
a client lease db holds the ip, mac addresses and lease time of all clients having a dynamic ip address. when the router reboots this db is lost. so if you are in a very big lan with many clients it can easily happen that client gets an ip address that was already assignet to a different client before the reboot. you can fix this by rebooting all clients or wait until the lease time is over.
static leases are stored elsewhere - not in the client lease db.
I've been trying to answer this for myself. I know its an old post. But is this the case? Is storing the client lease db in either place practially useless for home lans? _________________ Jim
Netgear R7000
Kong's 24800M OC to 1200,800
Previously:
Asus RT-N66U
Linksys E3000
Linksys WRT54GS Version 2.1
Buffalo WHR-HP-G54
Linksys WRT54G Version 1.1
This issue seems to persist in r29440 for Asus RT-AC68U. In my case, with "Use NVRAM for client lease DB" checked, my wl0.1 clients do not get a DHCP-assigned IP address; they get address 169.254.x.y.
I guess the only reason why anyone would need to enable this option is for static address allocation, otherwise it is a waste of memory if all you have is dynamic clients.