Re: Static IP outside of router DHCP range

"ohaya" <ohaya@xxxxxxx> wrote in message news:1eXtm.172704$8B7.31264@xxxxxxxxxxxxxxx


ohaya wrote:



Smarty wrote:

"ohaya" <ohaya@xxxxxxx> wrote in message news:xAVtm.45849$JG1.27409@xxxxxxxxxxxxxxx



Smarty wrote:

"VanguardLH" <V@xxxxxxxxx> wrote in message news:h987jc$ea5$1@xxxxxxxxxxxxxxxxxxxx

Smarty wrote:

The interest in Mac addresses I stated was merely
to explore the ironic fact that each of my 8 media player boxes has a
clearly defined MAC address which my video server "could" use to facilitate
and stabilize my re-boot problem, yet there is no (apparent) way to take
advantage of them. This would avoid the need for DHCP entirely, whereas now
each of these 8 devices has to initiate a DHCP, then BootP process which can
take tens of minutes after a power glitch. I am hoping that fixing the video
server IP statically will at least avoid the problem of the clients finding
the server after a server IP address change.




As I recall (been a long time), the clients that use BootP will pull
their code from a configured server. So once you fix to a static IP
address for the server, DHCP isn't involved anymore. Well, it's still
involved for the clients if they are still using DHCP but you could
change them to static IP addresses, too, and complete get rid of DHCP.
However, I don't think DHCP is what is taking so long. Do the clients
actually still want to use BootP to get an IP address assigned to them
if they were also using a static IP address? Unless you actually need
DHCP from the router, you could turn it off in the router and use static
IP addresses for all your hosts. With them all using static IP
addresses, none of them would need to use DHCP and probably not BootP.





Unfortunately my 8 clients are little $50 boxes with an Ethernet port and yellow, red, and white outputs for composite NTSC video and stereo audio, but no provisions whatsoever to flash their NVRAM. I think they are actually PROM'ed with soldered-in firmware, and they have no ability to have static IP assignments in their boot code. My 8 boxes have the so-called "Rev 1.0" boot ROM which makes them the least capable of all the ones which Hauppage offers. They are vintage-1995 hardware.

So I have no way to either reserve IP addresses based on Mac addresses, nor do I have a way to set them up as static.

I still am wondering if my Netgear switches truly have any "memory" of the ports associated with specific IP addresses of the connected clients, as they have no reset or reboot function as far as I know. It seems that removing power from the switches and then bringing them back up again does force a "reboot" of some type, since they seem to connect and work quickly after the power is re-cycled. I know that switches create a routing table so as to not multicast / flood all of the ports when a device is only present at one port. It just is not clear to me under what circumstances this table is updated, or for that matter built from scratch.

Thanks once again for your assistance.




Hi,

A bit weird idea, but maybe instead of using those Netgear switches, use a hub? That should eliminate any concerns that the hub is persisting information about which client/IP/MAC is on which port?

Jim

P.S. BTW, what's the model # of the Netgear switch(es)?



Thanks Jim. I will try the hub idea. Weird or not, it may solve my problem........
The Netgear switches here are model G5605 10/100/1000 Mbit/sec Gigabit 5 port switches.



Hi,

I'm assuming that you meant "GS605", rather than "G5605" :)?

Jim



Hi,

Assuming that it is a "GS605", according to Netgear, that has a 4K "MAC Database".

According to this (not a Netgear page):

http://www.tejasnetworks.com/technology/tech_packet_ernet-swit-macadd.shtml

it says:

"Every switch has a limitation to the number of MAC addresses that can be stored in the table. A large MAC address table size ensures that the node's MAC address tables don't get filled up during peak-traffic. There is also a provision for aging of learned entries. At times, Ethernet nodes (which are identified by their MAC addresses) can shift from one port to another. In this case, aging is required to ensure that the MAC address table reflects the current topology. The aging time is configurable in accordance to 802.1d."

I'm guessing that unmanaged, consumer-grade switches like the GS605 assume that you just live with the built-in "aging", and that if you want a switch that allows you to clear that MAC database/table, you'll need to go to a managed switch (one that you can connect into and to which you can issue commands).

If you're curious, you might try to check with Netgear support, or maybe post on their forums:

http://forum1.netgear.com/

and MAYBE someone there can tell you what the aging algorithm or period is. It looks like most consumer type stuff just says it supports aging, but doesn't say what that is.

In any event, it doesn't look like there'd be any way to programmatically clear the database, so you may be stuck with what you're doing, powering the switch(es) off/on...

Jim



Jim,

I have really learned a lot from your replies, and thank you for your kind assistance. These Netgear switches (sorry for the typo in the model number) are indeed cheap consumer switches, and I did not expect to find any way to change their aging out process. The Netgears were on sale at Newegg and I bought a bunch of them, but never expected that the specific port management performance made any difference. In this case it appears to matter.

I have a better system now that I have the video server pinned to a fixed IP. I can live with it the way it is, since I am not prepared to make any big investments in a new router, managed switches, etc.

Thanks once again. Your explanations have been excellent.

.

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