Untrustworthy DHCP leases

Untrustworthy DHCP leases

Post by gerr » Mon, 10 Jul 2000 04:00:00

I'm trying to find out how linux (newbie to linux) handles untrustworthy
DHCP leases.

In particular, MediaOne chooses to change subnets on your line from time to
time even though valid leases are outstanding. An example:

July 7th they switched me from

IP      24.128.253.x


IP      24.91.40.x

Unfortunately, I still had a lease and my "old" gateway was unreachable.

At the time, I was connected via a LinkSys router which actually believed
M1's lease information. I could have waited 36 hours (about 1/2 the lease
duration) and the linksys probably would have renewed and received a proper

I'm considering making my linux box the router. How does Linux (Mandrake
7.1) deal with loss of connectivity?

So far I've found, in this situation:

Linksys Routers - die until they renew or reset
UGate routers - same
Win9x - same
Win2k - renews if connection is lost

Clearly, M1 shouldn't do this but they do. Does Linux behave like Win2k or
could a simple script be scheduled to ping the gateway (it would have to
figure that out from the lease) and force a release/renue if the gateway

There are networks with multiple DHCP servers and multiple gateways so I
doubt I must re-invent the wheel <G>


NO_SPAM added to my email address to confuse robots


1. no dhcp leases in leases file


I don't know if this is the right forum to ask a question like the
following, so please tell me if this not the right place, further I'm quite
a freebsd newbie so please forgive me asking this if it seems to be

The question is:

I've installed a dhcp server as described in the freebsd handbook on my
freshly installed FBSD 4.6 box and it works perfectly: my windows clients
all get their ip-adresses and stuff - but the leases do not appear in the
/var/db/hdcpd.leases file - afaik they should appear there ... would you
please explain to me what's the problem...??

Thanks in advance, bye

Max Wiertz

2. GS reliably crashes Linux with the following input:

3. How to Release a DHCP lease with dhclient?

4. Minimal NIS on AIX 3.1.5

5. Solaris (8) DHCP client: wait forever, no lease and single user mode

6. syslog local0-7

7. DHCP - lease re-new needs NETWORK RESTART ?!?

8. Bridged OpenBSD v3.1 Firewall Problem

9. DHCP not renewing lease

10. DHCP not renegotiating after a lease expiration

11. DHCP Lease

12. DHCP Leased Time

13. 1 * UNJcchBaj-Pump renewing DHCP lease?