DHCP table doesn't show Sun workstations

[Michael Moeller]

Hi,

does somebody know why the router (Linksys RV042) sometimes deletes
my Sun machines from its dhcp table? Networking doesn't get
interrupted, though. PCs and Macs always appear as they should.

Regards,
Michael

[Edward Kroeze]

Post by Michael Moeller
Hi,
does somebody know why the router (Linksys RV042) sometimes deletes
my Sun machines from its dhcp table? Networking doesn't get interrupted,
though. PCs and Macs always appear as they should.

Could it be a difference in DHCP-address lease refresh time on the Sun
machines compared to the other ones?
Or maybe a firewall configuration (on the Suns?) that causes the Linksys not
to detect the Sun machines anymore after the inital address lease?

Regards,

Edward

[Michael Moeller]

Post by Edward Kroeze

Post by Michael Moeller
Hi,
does somebody know why the router (Linksys RV042) sometimes deletes
my Sun machines from its dhcp table? Networking doesn't get
interrupted, though. PCs and Macs always appear as they should.

Could it be a difference in DHCP-address lease refresh time on the Sun
machines compared to the other ones?
Or maybe a firewall configuration (on the Suns?) that causes the Linksys
not to detect the Sun machines anymore after the inital address lease?
Regards,
Edward

Good questions. The Suns are older SPARCs recommissioned for some
programming tasks with Sol 2.6 "out of the box". I haven't configured
any firewall. I think there isn't one by default. At least ftp, rlogin,
ircd, etc. works without further ado.

Dhcp table says lease refresh time is the same for all machines.

To put it in other words: why does the router, if it has a problem
regarding older Lance Ethernet cards, cross them off its dhcp table
while keeping them connected? To me this makes no sense.

Regards
Michael

[Bruce Esquibel]

Post by Michael Moeller
To put it in other words: why does the router, if it has a problem
regarding older Lance Ethernet cards, cross them off its dhcp table
while keeping them connected? To me this makes no sense.

Just a shot in the dark but are the sparcs configured to use dhcp?

I've noticed on some low end/consumer routers, it only counts dhcp clients,
if they actually were assigned an address via dhcp. If the machine is using
a static address within the range of ip addresses dhcp is using, it seems to
be present until the renew time, then fades away from the table.

I always figured it did that to initially lockout the ip address so it's not
issued and when it tried to renew the lease, it then figures out it's static
then drops it from the dhcp table of clients.

It's still there, just not in the dhcp client table.

Probably varies router to router but the 2wire brand seems to do that also.

On those, if you have a mix of dhcp clients and static ones, the view of the
"home network" via it's admin web interface is next to worthless.

-bruce
***@ripco.com

[Michael Moeller]

Post by Bruce Esquibel

Post by Michael Moeller
To put it in other words: why does the router, if it has a problem
regarding older Lance Ethernet cards, cross them off its dhcp table
while keeping them connected? To me this makes no sense.

Just a shot in the dark but are the sparcs configured to use dhcp?
I've noticed on some low end/consumer routers, it only counts dhcp clients,
if they actually were assigned an address via dhcp. If the machine is using
a static address within the range of ip addresses dhcp is using, it seems to
be present until the renew time, then fades away from the table.
I always figured it did that to initially lockout the ip address so it's not
issued and when it tried to renew the lease, it then figures out it's static
then drops it from the dhcp table of clients.
It's still there, just not in the dhcp client table.
Probably varies router to router but the 2wire brand seems to do that also.
On those, if you have a mix of dhcp clients and static ones, the view of the
"home network" via it's admin web interface is next to worthless.
-bruce

The SPARCs are configured to use dhcp. However, during setup of the OS
you are asked to assign an IP to the machine. I choosed a valid one
in some distance to the ones normally used by dhcp just to continue with
the setup. I didn't inform the router about this. Can it be the router
knows of the SPARCs static IP despite dhcp? If this is the case you
probably gave the right explanation.

Regards,
Michael

[Bruce Esquibel]

Post by Michael Moeller
The SPARCs are configured to use dhcp. However, during setup of the OS
you are asked to assign an IP to the machine. I choosed a valid one
in some distance to the ones normally used by dhcp just to continue with
the setup. I didn't inform the router about this. Can it be the router
knows of the SPARCs static IP despite dhcp? If this is the case you
probably gave the right explanation.

Well, if "ifconfig -a" on the sparcs are only showing one ip on the
interface(s), I suppose it's possible the original ip address you assigned
is "stuck" in the router.

I haven't used one of the Linksys you have, but again on the 2wire routers
there is some flaw with the way it does discovery and stores the tables. It
seems on those, it sees a mac address, obtains the ip info, stores both but
only uses the ip address in the menus.

The problem there is, if you have 2 (or more) ip addresses assigned to the
interface, it really confuses the shit out of it. Everything works fine but
displaying either the "home network" or firewall table, one or the other
shows up, never both but sometimes neither.

A similar problem occurs when the mac address changes but the ip address is
the same. Like if had two machines you were testing, one at a time, assigned
the same ip address to both. The 2wire associates the mac address to the ip
of the 1st machine and when that is down and the other machine is up, it
works but it's not likely you'll find it in any of the tables.

Again it works fine as far as routing, it's just the display tables for
dhcp, the "home network" and firewall are wrong.

Besides doing a factory reset to clear it, on the 2wire there is an extended
admin menu that contains a clear function for all the tables.

I'm just saying in your case it's probably just a bug in the router similar
to the 2wire with the dhcp table. It's just a display/management problem.

-bruce
***@ripco.com

[Michael Moeller]

Post by Bruce Esquibel

Post by Michael Moeller
The SPARCs are configured to use dhcp. However, during setup of the OS
you are asked to assign an IP to the machine. I choosed a valid one
in some distance to the ones normally used by dhcp just to continue with
the setup. I didn't inform the router about this. Can it be the router
knows of the SPARCs static IP despite dhcp? If this is the case you
probably gave the right explanation.

Well, if "ifconfig -a" on the sparcs are only showing one ip on the
interface(s), I suppose it's possible the original ip address you assigned
is "stuck" in the router.
I haven't used one of the Linksys you have, but again on the 2wire routers
there is some flaw with the way it does discovery and stores the tables. It
seems on those, it sees a mac address, obtains the ip info, stores both but
only uses the ip address in the menus.
The problem there is, if you have 2 (or more) ip addresses assigned to the
interface, it really confuses the shit out of it. Everything works fine but
displaying either the "home network" or firewall table, one or the other
shows up, never both but sometimes neither.
A similar problem occurs when the mac address changes but the ip address is
the same. Like if had two machines you were testing, one at a time, assigned
the same ip address to both. The 2wire associates the mac address to the ip
of the 1st machine and when that is down and the other machine is up, it
works but it's not likely you'll find it in any of the tables.
Again it works fine as far as routing, it's just the display tables for
dhcp, the "home network" and firewall are wrong.
Besides doing a factory reset to clear it, on the 2wire there is an extended
admin menu that contains a clear function for all the tables.
I'm just saying in your case it's probably just a bug in the router similar
to the 2wire with the dhcp table. It's just a display/management problem.
-bruce

Thank you for clarifiying this. "Bug in the router" was in fact my first
unaware assumption which seems to prove true under the circumstances.

I tried to upgrade the firmware but the installer didn't work. There is
a cgi script issue I can't be bothered to track down at the moment.

Regards,
Michael

[Michael Moeller]

Post by Michael Moeller

Post by Bruce Esquibel

Post by Michael Moeller
The SPARCs are configured to use dhcp. However, during setup of the OS
you are asked to assign an IP to the machine. I choosed a valid one
in some distance to the ones normally used by dhcp just to continue with
the setup. I didn't inform the router about this. Can it be the router
knows of the SPARCs static IP despite dhcp? If this is the case you
probably gave the right explanation.

Well, if "ifconfig -a" on the sparcs are only showing one ip on the
interface(s), I suppose it's possible the original ip address you assigned
is "stuck" in the router.
I haven't used one of the Linksys you have, but again on the 2wire routers
there is some flaw with the way it does discovery and stores the tables. It
seems on those, it sees a mac address, obtains the ip info, stores both but
only uses the ip address in the menus.
The problem there is, if you have 2 (or more) ip addresses assigned to the
interface, it really confuses the shit out of it. Everything works fine but
displaying either the "home network" or firewall table, one or the other
shows up, never both but sometimes neither.
A similar problem occurs when the mac address changes but the ip address is
the same. Like if had two machines you were testing, one at a time, assigned
the same ip address to both. The 2wire associates the mac address to the ip
of the 1st machine and when that is down and the other machine is up, it
works but it's not likely you'll find it in any of the tables.
Again it works fine as far as routing, it's just the display tables for
dhcp, the "home network" and firewall are wrong.
Besides doing a factory reset to clear it, on the 2wire there is an extended
admin menu that contains a clear function for all the tables.
I'm just saying in your case it's probably just a bug in the router similar
to the 2wire with the dhcp table. It's just a display/management problem.
-bruce

Thank you for clarifiying this. "Bug in the router" was in fact my first
unaware assumption which seems to prove true under the circumstances.
I tried to upgrade the firmware but the installer didn't work. There is
a cgi script issue I can't be bothered to track down at the moment.
Regards,
Michael

Just for the sake of completeness: deleting the line

<static IP> <workstation-name> loghost

from /etc/inet/hosts solves all the problems. Now dhcp can add the IP to
this file and the machine gets properly listed in the routers dhcp table.

Regards,
Michael