Short version - IPCOP is haning out DHCP addresses VERY VERY slowly - like
on every 10 minutes.
I did not find any Rogue devices. I unplugged the 3 WAPs I added last week
and still not go.
Watching what is going on via the web interface it IS giving out addresses -
but REAL REAL slow. I had 4 IP addresses doled out to computers that had
gotten an IP from DHCP before- but during that time I had a laptop that
tried to get an IP via DHCP and it timed out and failed. The another DHCP
address was given out - but not to this laptop. Seems like a file might be
corrupted - how do I rest / erase the DHCP cache of addresses?
Not sure why - but I also suspect my config file. Not sure if it changed or
if it is right. Here is what the DHCP.CONF file in /etc has:
ddns-update-style none;
deny bootp; #default
authoritative;
subnet 10.0.0.0 netmask 255.255.0.0 #GREEN
{
range 10.0.2.50 10.0.2.255;
option subnet-mask 255.255.0.0;
option domain-name "altamont.ipcop";
option routers 10.0.0.1;
option domain-name-servers 10.0.0.1;
default-lease-time 3600;
max-lease-time 7200;
} #GREEN
host fix0 # Sperintendent Laptop - WIRED
{
hardware ethernet 00:0f:1f:cd:33:44;
fixed-address 10.0.0.31;
}
I use 10.0.X.X IP's and I am running a class B so the subnet should be
255.255.0.0
The range of IP's is OK: I noticed that when I ran the Rogue DHCP checker
program it ALWAYS picked up the HIGHEST IP in the range - even if I change
the range and gave it MORE Ip's to hand out.
I ran a Wireshark while a box was trying to get an IP and the only DHCP
packets I saw were DHCP Discovery packets from 0.0.0.0 to 255.255.255.255
with a transaction IP number and that is it. It is almost like the DHCP
server is not responding. No DHCP Offer / DHCP Requests or DHCP Ack packets
that I could see.
But when I check the leases - it looks like the server has doled out another
one - VERY VERY SLOW!
Thank in advance for any help!
-----Original Message-----
From: tech-geeks-boun...@tech-geeks.org
[mailto:tech-geeks-boun...@tech-geeks.org] On Behalf Of Aaron Hackney
Sent: Sunday, September 26, 2010 1:39 PM
To: Tech-Geeks Mailing List
Subject: Re: [tech-geeks] IPCop - DHCP not responding.
If you are running Cisco switches, verify that spanning-tree portfast
is enabled on all non-switch uplink ports.
Run wireshark on an effected workstation. Examine the following traffic:
DHCP discovery (From Workstation)
DHCP Offer (From Server)
DHCP Request (From Workstation)
DHCP Ack (From Server)
This may give you some deeper insight as to what is going on behind the
scenes.
As to what may have changed: A change in the network topology (A
switching loop, let's say or too many switches in line) could have
changed the time it takes a broadcast to propagate. Your DHCP server,
for what ever reason, may have exhausted it's scope (I've seen this
behavior with a misbehaving NIC and/or malware). Just brainstorming
for you....
HTH
-A
On Sat, Sep 25, 2010 at 10:45 PM, Charlie Kinsella
<ckinse...@dixonschools.org> wrote:
> Did you add any new switches in the building? Aside from the wireless any
> new anything?
>
> Charles Kinsella
> Technology Director
> Dixon Public Schools
> ckinse...@dixonschools.org
> (815) 284-7725
>
>
> ________________________________
>
> Maybe I am not being clear. The DHCP server is not dishing out ANY
> addresses to ANY device that is contacting it. I tried a few IPods and a
> few workstations and when I set them to automatic discover / DHCP - they
try
> for a while and then fail. The PC boxes tell me I have a limited
connection
> and when I check the IP "assigned" to the box it is a 169.X.X.X address
> which is not really an assigned address - but what a windows box will plug
> in if the DHCP process fails.
>
> Now the weird parts
> - This was all working fine before late Thursday / Friday AM
> - From what I can tell the DHCP server IS up and running
> - When I use the Microsoft Rogue DHCP tool to see if there is more than
one
> DHCP server on the network it sees the one DHCP server (The IPCop box) AND
> it reports a valid IP that the DHCP server would be handing out
> - When I down the DHCP server and run the Rogue DHCP server tool I see NO
> DHCP servers on the network.
>
> So - the DHCP is there, it is running, it is handing out IP's to the Rogue
> DHCP server tool
> BUT
> No device / PC etc. is successful in communicating with the DHCP server
and
> assigning an IP that the server is providing.
>
> Any ideas would be GREATLY appreciated!
>
>
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>
--
"Don't ask yourself what the world needs. Ask yourself what makes you
come alive and then go do that. Because what the world needs is people
who have come alive." -Dr. Howard Thurman
******************************
Aaron Keith Hackney
aa...@aaronkeithstudios.com
Cell 210.325.2196
******************************
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