How does a network/router recognize new IP addresses?

How does a network/router recognize new IP addresses?

Post by Dave Harm » Sun, 12 Dec 1999 04:00:00

I'm having difficulty getting some IP addresses recognized. I have a
subnet of 16 registered addresses, let's call it to

I have a box set up right now with, 3, and 4 all on eth0
(each with a web site), using as the gateway. Works a
treat, and has been working this way for almost a year.

I've got a new machine with RH 6.1. Thee NICs,
(connects to the gateway), (connects to a dmz) and one
with a local address. I plug in the new box and I can ping the 13 & 14
addresses from the web no problem. But even though I add
to the first nic I'm unable to ping that address, except on the local
network where it works fine. (the old box has been disconnected
entirely - there's no ip address conflict).

From what I can gather a router somewhere upstream of me is
supposed to periodically broadcast an ARP request to my subnet. I'm
trying to find out from my ISP if this is the case, and if so how
often. I tried adding an ARP entry for on that nic but it
didn't seem to make any difference. I understand I'd also have to do
this for any machines I want to add on the local subnet, but right now
I can't even get a single box to work correctly.

Am I on the right track? I'd appreciate any help at all. Thanks.


Dave Harms


How does a network/router recognize new IP addresses?

Post by dave » Sun, 12 Dec 1999 04:00:00

OK, hold on a sec. Problem narrowed down. It appears to have been a bad
routing table. So now I can talk to all the IP addresses on the machine
connected to the net, which is actually a firewall box.

Sometimes framing the question leads to the answer. Sorry for the first



1. New to Networking: WinNT network, Dynamic IP addressing, Passwords..?

Hello All,
I am currently starting a complete, fresh, install of Linux Slackware 3.3.  I
have purchased and installed an appropriate Token ring card that will work
with Linux.  I will have a Win95/Linux dual boot.  My computer here at work is
on a WinNT network with password protection to hook into network drives and
our IP addressing is allocated dynamically.  Can someone tell me what topics I
will need to address and what documents I should read up on so I can connect
to our network with Linux??  I have looked at some of the HOWTO's and they all
seem to assume a static IP address.  I have heard a  little about SAMBA, will
I need it or is it more for a server on a network?

TIA and I appreciate any input!!


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